Hux feels himself growing almost comfortable, and shakes himself to remind himself where he is. A level editor has been included with the game to allow you to expand upon the game. Solo stands from his chair. “I’m getting hungry,” he says, and, leveling a smile at Hux, “What do you want to eat?” Hux blinks up at him. This table summarizes the modal behaviour: Examples: List contents of an archive: Extract contents of an archive into the current directory: Create an archive of the current directory: When used in the cpio style, the find command can be used to get a list of files to be archived: Copy current directory tree to another location: The target directory must exist beforehand! This demo includes a tutorial and lets you try five different layouts available in the full game.
He hands a plate to Hux and another to the beast, settling in the pilot’s chair with his own. However, there are many instances when you may end up deleting files and folders by mistake. The hairy creature roars and adjusts itself in its seat, flipping switches and pushing buttons and preparing to leave hyperspace. September 24, 2016 – New York 2:30-9pm EST Arts on Site – 12 St. Both servers below flip flop details because they are virtuals sharing the same serial number.
They won't come with a 10 year warranty (that's Ploom's own warranty and why they charge $250) but they will come with a 3 year manufacturers warranty, which is a solid warranty for the price. The host id is ordinarily seen in hexadecimal as the output of the Solaris hostid command. The shouting is coming from some other source, he realizes as it begins again. Here I am just sharing few tips to find the server serial number from Oracle Solaris. He feels a rush of adrenaline at the thought that every single one of these people, his peers, have put their lives in his hands. “We are the top students at the Academy.
Provided is an integral 3D humic acid-carbon hybrid foam composed of multiple pores and pore walls, wherein pore walls contain single-layer or few-layer humic acid sheets chemically bonded by a carbon material at their edges and have a carbon material-to-humic acid weight ratio from 1/200 to 1/2, wherein the few-layer humic acid sheets have 2-10 layers of stacked substantially hexagonal carbon planes having an inter-plane spacing d.sub.002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction and the single-layer or few-layer humic acid sheets contain 0.01% to 25% by weight of non-carbon elements wherein said humic acid is selected from oxidized humic acid, reduced humic acid, fluorinated humic acid, chlorinated humic acid, brominated humic acid, iodized humic acid, hydrogenated humic acid, nitrogenated humic acid, doped humic acid, chemically functionalized humic acid, or a combination thereof.
1. An integral 3D humic acid-carbon hybrid foam composed of multiple pores and pore walls, wherein said pore walls contain single-layer or few-layer humic acid sheets chemically bonded by a carbon material at their edges and have a carbon material-to-humic acid weight ratio from 1/200 to 1/2, wherein few-layer is defined as having two to ten atomic layers and wherein said few-layer humic acid sheets have stacked substantially hexagonal carbon planes having an inter-plane spacing d.sub.002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction and said single-layer or few-layer humic acid sheets contain 0.01% to 25% by weight of non-carbon elements wherein said humic acid is selected from oxidized humic acid, reduced humic acid, fluorinated humic acid, chlorinated humic acid, brominated humic acid, iodized humic acid, hydrogenated humic acid, nitrogenated humic acid, doped humic acid, chemically functionalized humic acid, or a combination thereof.
4. The integral 3D humic acid-carbon hybrid foam of claim 1, wherein said foam contains a content of non-carbon elements in the range of 0.01% to 20% by weight and said non-carbon elements include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen, or boron.
5. The integral 3D humic acid-carbon hybrid foam of claim 1, wherein said pore walls contain fluorinated humic acid and said foam contains a fluorine content from 0.01% to 15% by weight.
6. The 3D humic acid-carbon hybrid foam of claim 1, wherein said pore walls contain oxidized humic acid and said foam contains an oxygen content from 0.01% to 20% by weight.
8. The 3D humic acid-carbon hybrid foam of claim 1, which is in a continuous-length roll sheet form having a thickness from 100 nm to 10 cm and a length of at least 2 meters and is produced by a roll-to-roll process.
9. The 3D humic acid-carbon hybrid foam of claim 1, wherein said foam has an oxygen content or non-carbon content less than 1% by weight, and said pore walls have stacked hexagonal carbon planes having an inter-planar spacing from 0.3354 nm to 0.35 nm, a thermal conductivity of at least 250 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,500 S/cm per unit of specific gravity.
10. The 3D humic acid-carbon hybrid foam of claim 1, wherein said foam has an oxygen content or non-carbon content less than 0.01% by weight and said pore walls contain stacked hexagonal carbon planes having an inter-planar spacing from 0.3354 nm to 0.34 nm, a thermal conductivity of at least 300 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,000 S/cm per unit of specific gravity.
11. The 3D humic acid-carbon hybrid foam of claim 1, wherein said foam has an oxygen content or non-carbon content no greater than 0.01% by weight and said pore walls contain stacked hexagonal carbon planes having an inter-planar spacing from 0.3354 nm to 0.336 nm, a thermal conductivity of at least 350 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,500 S/cm per unit of specific gravity.
12. The 3D humic acid-carbon hybrid foam of claim 1, wherein said foam has pore walls containing stacked hexagonal carbon planes having an inter-planar spacing from 0.3354 nm to 0.336 nm, a thermal conductivity greater than 400 W/mK per unit of specific gravity, and/or an electrical conductivity greater than 4,000 S/cm per unit of specific gravity.
18. A method to separate oil from water, said method comprising the steps of: a. providing an oil-absorbing element comprising the integral 3D humic acid-carbon hybrid foam of claim 1; b. contacting an oil-water mixture with said element, which absorbs the oil from the mixture; c. retreating the element from the mixture and extracting the oil from the element; and d. reusing the element.
19. A method to separate an organic solvent from a solvent-water mixture or from a multiple-solvent mixture, said method comprising the steps of: a. providing an organic solvent-absorbing or solvent-separating element comprising the integral 3D humic acid-carbon hybrid foam of claim 1; b. bringing said element in contact with an organic solvent-water mixture or a multiple-solvent mixture containing a first solvent and at least a second solvent; c. allowing said element to absorb the organic solvent from the mixture or separate said first solvent from said at least second solvent; d. retreating the element from the mixture and extracting the organic solvent or first solvent from the element; and e. reusing the element.
21. The thermal management device of claim 20, which contains a device selected from a heat exchanger, heat sink, heat pipe, high-conductivity insert, conductive plate between a heat sink and a heat source, heat-spreading component, heat-dissipating component, thermal interface medium, or thermoelectric or Peltier cooling device.
[0001] The present invention relates generally to the field of carbon/graphite foams and, more particularly, to a new form of porous carbon material herein referred to as an integral 3D humic acid-carbon hybrid foam and a method of producing same.
[0002] Carbon is known to have five unique crystalline structures, including diamond, fullerene (0-D nano graphitic material), carbon nano-tube or carbon nano-fiber (1-D nano graphitic material), graphene (2-D nano graphitic material), and graphite (3-D graphitic material).
[0003] The carbon nano-tube (CNT) refers to a tubular structure grown with a single wall or multi-wall. Carbon nano-tubes (CNTs) and carbon nano-fibers (CNFs) have a diameter on the order of a few nanometers to a few hundred nanometers. Their longitudinal, hollow structures impart unique mechanical, electrical and chemical properties to the material. The CNT or CNF is a one-dimensional nano carbon or 1-D nano graphite material. However, CNTs are difficult to produce and are extremely expensive. Further, CNTs are known to be difficult to disperse in a solvent or water and difficult to mix with other materials. These characteristics have severely limited their scope of application.
[0004] A single-layer graphene sheet is composed of carbon atoms occupying a two-dimensional hexagonal lattice. Multi-layer graphene is a platelet composed of more than one graphene plane. Individual single-layer graphene sheets and multi-layer graphene platelets are herein collectively called nano graphene platelets (NGPs) or graphene materials. NGPs include pristine graphene (essentially 99% of carbon atoms), slightly oxidized graphene 5% by weight of oxygen), and graphene oxide (.gtoreq.5% by weight of oxygen).
[0005] NGPs have been found to have a range of unusual physical, chemical, and mechanical properties. For instance, graphene was found to exhibit the_highest intrinsic strength and highest thermal conductivity of all existing materials. Although practical electronic device applications for graphene (e.g., replacing Si as a backbone in a transistor) are not envisioned to occur within the next 5-10 years, its application as a nano filler in a composite material and an electrode material in energy storage devices is imminent. The availability of processable graphene sheets in large quantities is essential to the success in exploiting composite, energy, and other applications for graphene.
[0006] Our research group was among the first to discover graphene [B. Z. Jang and W. C. Huang, "Nano-scaled Graphene Plates," U.S. patent application Ser. No. 10/274,473, submitted on Oct. 21, 2002; now U.S. Pat. No. 7,071,258 (Jul. 4, 2006)]. The processes for producing NGPs and NGP nanocomposites were previously reviewed by us [Bor Z. Jang and A Zhamu, "Processing of Nano Graphene Platelets (NGPs) and NGP Nanocomposites: A Review," J. Materials Sci. 43 (2008) 5092-5101]. Four main prior-art approaches have been followed to produce NGPs. Their advantages and shortcomings are briefly summarized as follows:
[0007] The first approach (FIG. 1) entails treating natural graphite powder with an intercalant and an oxidant (e.g., concentrated sulfuric acid and nitric acid, respectively) to obtain a graphite intercalation compound (GIC) or, actually, graphite oxide (GO). [William S. Hummers, Jr., et al., Preparation of Graphitic Oxide, Journal of the American Chemical Society, 1958, p. 1339.] Prior to intercalation or oxidation, graphite has an inter-graphene plane spacing of approximately 0.335 nm (L.sub.d=1/2d.sub.002=0.335 nm). With an intercalation and oxidation treatment, the inter-graphene spacing is increased to a value typically greater than 0.6 nm. This is the first expansion stage experienced by the graphite material during this chemical route. The obtained GIC or GO is then subjected to further expansion (often referred to as exfoliation) using either a thermal shock exposure or a solution-based, ultrasonication-assisted graphene layer exfoliation approach.
[0008] In the thermal shock exposure approach, the GIC or GO is exposed to a high temperature (typically 800-1,050.degree. C.) for a short period of time (typically 15 to 60 seconds) to exfoliate or expand the GIC or GO for the formation of exfoliated or further expanded graphite, which is typically in the form of a "graphite worm" composed of graphite flakes that are still interconnected with one another. This thermal shock procedure can produce some separated graphite flakes or graphene sheets, but normally the majority of graphite flakes remain interconnected. Typically, the exfoliated graphite or graphite worm is then subjected to a flake separation treatment using air milling, mechanical shearing, or ultrasonication in water. Hence, approach 1 basically entails three distinct procedures: first expansion (oxidation or intercalation), further expansion (or "exfoliation"), and separation.
[0009] In the solution-based separation approach, the expanded or exfoliated GO powder is dispersed in water or aqueous alcohol solution, which is subjected to ultrasonication. It is important to note that in these processes, ultrasonification is used after intercalation and oxidation of graphite (i.e., after first expansion) and typically after thermal shock exposure of the resulting GIC or GO (after second expansion). Alternatively, the GO powder dispersed in water is subjected to an ion exchange or lengthy purification procedure in such a manner that the repulsive forces between ions residing in the inter-planar spaces overcome the inter-graphene van der Waals forces, resulting in graphene layer separations.
[0010] There are several major problems associated with this conventional chemical production process: [0011] (1) The process requires the use of large quantities of several undesirable chemicals, such as sulfuric acid, nitric acid, and potassium permanganate or sodium chlorate. [0012] (2) The chemical treatment process requires a long intercalation and oxidation time, typically 5 hours to five days. [0013] (3) Strong acids consume a significant amount of graphite during this long intercalation or oxidation process by "eating their way into the graphite" (converting graphite into carbon dioxide, which is lost in the process). It is not unusual to lose 20-50% by weight of the graphite material immersed in strong acids and oxidizers. [0014] (4) The thermal exfoliation requires a high temperature (typically 800-1,200.degree. C.) and, hence, is a highly energy-intensive process. [0015] (5) Both heat- and solution-induced exfoliation approaches require a very tedious washing and purification step. For instance, typically 2.5 kg of water is used to wash and recover 1 gram of GIC, producing huge quantities of waste water that need to be properly treated. [0016] (6) In both the heat- and solution-induced exfoliation approaches, the resulting products are GO platelets that must undergo a further chemical reduction treatment to reduce the oxygen content. Typically even after reduction, the electrical conductivity of GO platelets remains much lower than that of pristine graphene. Furthermore, the reduction procedure often involves the utilization of toxic chemicals, such as hydrazine. [0017] (7) Furthermore, the quantity of intercalation solution retained on the flakes after draining may range from 20 to 150 parts of solution by weight per 100 parts by weight of graphite flakes (pph) and more typically about 50 to 120 pph. During the high-temperature exfoliation, the residual intercalate species retained by the flakes decompose to produce various species of sulfuric and nitrous compounds (e.g., NO.sub.x and SO.sub.x), which are undesirable. The effluents require expensive remediation procedures in order not to have an adverse environmental impact.
[0018] In 2002, our research team succeeded in isolating single-layer and multi-layer graphene sheets from partially carbonized or graphitized polymeric carbons, which were obtained from a polymer or pitch precursor [B. Z. Jang and W. C. Huang, "Nano-scaled Graphene Plates," U.S. patent application Ser. No. 10/274,473, submitted on Oct. 21, 2002; now U.S. Pat. No. 7,071,258 (Jul. 4, 2006)]. Mack, et al ["Chemical manufacture of nanostructured materials" U.S. Pat. No. 6,872,330 (Mar. 29, 2005)] developed a process that involved intercalating graphite with potassium melt and contacting the resulting K-intercalated graphite with alcohol, producing violently exfoliated graphite containing NGPs. The process must be carefully conducted in a vacuum or an extremely dry glove box environment since pure alkali metals, such as potassium and sodium, are extremely sensitive to moisture and pose an explosion danger. This process is not amenable to the mass production of NGPs.
[0019] Small-scale production of ultra-thin graphene sheets on a substrate can be obtained by thermal decomposition-based epitaxial growth and a laser desorption-ionization technique. [Walt A. DeHeer, Claire Berger, Phillip N. First, "Patterned thin film graphite devices and method for making same" U.S. Pat. No. 7,327,000 B2 (Jun. 12, 2003)] Epitaxial films of graphite with only one or a few atomic layers are of technological and scientific significance due to their peculiar characteristics and great potential as a device substrate. However, these processes are not suitable for mass production of isolated graphene sheets for composite materials and energy storage applications.
[0020] Another process for producing graphene, in a thin film form (typically <2 nm in thickness), is the catalytic chemical vapor deposition process. This catalytic CVD involves catalytic decomposition of hydrocarbon gas (e.g. C.sub.2H.sub.4) on Ni or Cu surface to form single-layer or few-layer graphene. With Ni or Cu being the catalyst, carbon atoms obtained via decomposition of hydrocarbon gas molecules at a temperature of 800-1,000.degree. C. are directly deposited onto Cu foil surface or precipitated out to the surface of a Ni foil from a Ni--C solid solution state to form a sheet of single-layer or few-layer graphene (less than 5 layers). The Ni- or Cu-catalyzed CVD process does not lend itself to the deposition of more than 5 graphene planes (typically <2 nm) beyond which the underlying Ni or Cu layer can no longer provide any catalytic effect. The CVD graphene films are extremely expensive.
[0021] Yang, et al. ["Two-dimensional Graphene Nano-ribbons," J. Am. Chem. Soc. 130 (2008) 4216-17] synthesized nano graphene sheets with lengths of up to 12 nm using a method that began with Suzuki-Miyaura coupling of 1,4-diiodo-2,3,5,6-tetraphenyl-benzene with 4-bromophenylboronic acid. The resulting hexaphenylbenzene derivative was further derivatized and ring-fused into small graphene sheets. This is a slow process that thus far has produced very small graphene sheets.
[0022] Hence, an urgent need exists to have a new class of carbon nano materials that are comparable or superior to graphene in terms of properties, but can be produced more cost-effectively, faster, more scalable, and in a more environmentally benign manner. The production process for such a new carbon nano material requires a reduced amount of undesirable chemical (or elimination of these chemicals all together), shortened process time, less energy consumption, reduced or eliminated effluents of undesirable chemical species into the drainage (e.g., sulfuric acid) or into the air (e.g., SO.sub.2 and NO.sub.2). Furthermore, one should be able to readily make this new nano material into a foam structure that is relatively conductive thermally and electrically.
[0023] Generally speaking, a foam or foamed material is composed of pores (or cells) and pore walls (a solid material). The pores can be interconnected to form an open-cell foam. As an example, graphene foam is composed of pores and pore walls that contain a graphene material. There are three major methods of producing graphene foams, which are all tedious, energy-intensive, and slow:
[0024] The first method is the hydrothermal reduction of graphene oxide hydrogel that typically involves sealing graphene oxide (GO) aqueous suspension in a high-pressure autoclave and heating the GO suspension under a high pressure (tens or hundreds of atm) at a temperature typically in the range of 180-300.degree. C. for an extended period of time (typically 12-36 hours). A useful reference for this method is given here: Y. Xu, et al. "Self-Assembled Graphene Hydrogel via a One-Step Hydrothermal Process," ACS Nano 2010, 4, 4324-4330. There are several major issues associated with this method: (a) The high pressure requirement makes it an impractical method for industrial-scale production. For one thing, this process cannot be conducted on a continuous basis. (b) It is difficult, if not impossible, to exercise control over the pore size and the porosity level of the resulting porous structure. (c) There is no flexibility in terms of varying the shape and size of the resulting reduced graphene oxide (RGO) material (e.g. it cannot be made into a film shape). (d) The method involves the use of an ultra-low concentration of GO suspended in water (e.g. 2 mg/mL=2 g/L=2 kg/kL). With the removal of non-carbon elements (up to 50%), one can only produce less than 2 kg of graphene material (RGO) per 1000-liter suspension. Furthermore, it is practically impossible to operate a 1000-liter reactor that has to withstand the conditions of a high temperature and a high pressure. Clearly, this is not a scalable process for mass production of porous graphene structures.
[0025] The second method is based on a template-assisted catalytic CVD process, which involves CVD deposition of graphene on a sacrificial template (e.g. Ni foam). The graphene material conforms to the shape and dimensions of the Ni foam structure. The Ni foam is then etched away using an etching agent, leaving behind a monolith of graphene skeleton that is essentially an open-cell foam. A useful reference for this method is given here: Zongping Chen, et al., "Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapour deposition," Nature Materials, 10 (June 2011) 424-428. There are several problems associated with such a process: (a) the catalytic CVD is intrinsically a very slow, highly energy-intensive, and expensive process; (b) the etching agent is typically a highly undesirable chemical and the resulting Ni-containing etching solution is a source of pollution. It is very difficult and expensive to recover or recycle the dissolved Ni metal from the etchant solution. (c) It is challenging to maintain the shape and dimensions of the graphene foam without damaging the cell walls when the Ni foam is being etched away. The resulting graphene foam is typically very brittle and fragile. (d) The transport of the CVD precursor gas (e.g. hydrocarbon) into the interior of a metal foam can be difficult, resulting in a non-uniform structure, since certain spots inside the sacrificial metal foam may not be accessible to the CVD precursor gas.
[0026] The third method of producing graphene foam also makes use of a sacrificial material (e.g. colloidal polystyrene particles, PS) that is coated with graphene oxide sheets using a self-assembly approach. For instance, Choi, et al. prepared chemically modified graphene (CMG) paper in two steps: fabrication of free-standing PS/CMG films by vacuum filtration of a mixed aqueous colloidal suspension of CMG and PS (2.0 .mu.m PS spheres), followed by removal of PS beads to generate 3D macro-pores [B. G. Choi, et al., "3D Macroporous Graphene Frameworks for Supercapacitors with High Energy and Power Densities," ACS Nano, 6 (2012) 4020-4028.]. Choi, et al. fabricated well-ordered free-standing PS/CMG paper by filtration, which began with separately preparing a negatively charged CMG colloidal and a positively charged PS suspension. A mixture of CMG colloidal and PS suspension was dispersed in solution under controlled pH (=2), where the two compounds had the same surface charges (zeta potential values of +13.+-.2.4 mV for CMG and +68.+-.5.6 mV for PS). When the pH was raised to 6, CMGs (zeta potential=-29.+-.3.7 mV) and PS spheres (zeta potential=+51.+-.2.5 mV) were assembled due to the electrostatic interactions and hydrophobic characteristics between them, and these were subsequently integrated into PS/CMG composite paper through a filtering process. This method also has several shortcomings: (a) This method requires very tedious chemical treatments of both graphene oxide and PS particles. (b) The removal of PS by toluene also leads to weakened macro-porous structures. (c) Toluene is a highly regulated chemical and must be treated with extreme caution. (d) The pore sizes are typically excessively big (e.g. several .mu.m), too big for many useful applications.
[0027] The above discussion clearly indicates that every prior art method or process for producing graphene and graphene foams has major deficiencies. Thus, it is an object of the present invention to provide a new class of foam material that is thermally and electrically conducting and mechanically robust and to provide a cost-effective method of producing this class of foam.
[0028] Humic acid (HA) is an organic matter commonly found in soil and can be extracted from the soil using a base (e.g. KOH). HA can also be extracted, with a high yield, from a type of coal called leonardite, which is a highly oxidized version of lignite coal. HA extracted from leonardite contains a number of oxygenated groups (e.g. carboxyl groups) located around the edges of the graphene-like molecular center (SP.sup.2 core of hexagonal carbon structure). This material is slightly similar to graphene oxide (GO) which is produced by strong acid oxidation of natural graphite. HA has a typical oxygen content of 5% to 42% by weight (other major elements being carbon and hydrogen). HA, after chemical or thermal reduction, has an oxygen content of 0.01% to 5% by weight. For claim definition purposes in the instant application, humic acid (HA) refers to the entire oxygen content range, from 0.01% to 42% by weight. The reduced humic acid (RHA) is a special type of HA that has an oxygen content of 0.01% to 5% by weight.
[0029] The present invention is directed at a new class of graphene-like 2D materials (i.e. humic acid) that surprisingly can be used in a combination with carbon to form a hybrid foam. Thus, another object is to provide a cost-effective method of producing such a nano carbon foam (specifically, integral 3D humic acid-carbon hybrid foam) in large quantities. This method or process does not involve the use of an environmentally unfriendly chemical. This method enables the flexible design and control of the porosity level and pore sizes.
[0030] It is another object of the present invention to provide a humic acid-derived hybrid foam that exhibits a thermal conductivity, electrical conductivity, elastic modulus, and/or strength comparable to or greater than those of the conventional graphite foams, carbon foams, or graphene foams.
[0031] Yet another object of the present invention is to provide (a) a reduced humic acid-based hybrid foam that contains essentially all carbon only (<5% by weight of non-carbon content, preferably <1%, and further preferably <0.1%) and preferably have a meso-scaled pore size range (2-50 nm); and (b) humic acid foams that contain at least 5% by weight (typically from 5% to 42% by weight and most typically from 5% to 20%) of non-carbon elements that can be used for a broad array of applications.
[0032] Another object of the present invention is to provide products (e.g. devices) that contain an integral 3D humic acid-carbon foam of the present invention and methods of operating these products.
[0033] The present invention provides an integral 3D humic acid-carbon hybrid foam composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer humic acid sheets chemically bonded by a carbon material at their edges and have a carbon material-to-humic acid weight ratio from 1/200 to 1/2, wherein the few-layer humic acid sheets have 2-10 layers of stacked substantially hexagonal carbon planes having an inter-plane spacing d.sub.002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction and said single-layer or few-layer humic acid sheets contain 0.01% to 25% by weight of non-carbon elements, wherein humic acid is selected from oxidized humic acid, reduced humic acid, fluorinated humic acid, chlorinated humic acid, brominated humic acid, iodized humic acid, hydrogenated humic acid, nitrogenated humic acid, doped humic acid, chemically functionalized humic acid, or a combination thereof.
[0034] The hybrid foam typically has a density from 0.005 to 1.7 g/cm.sup.3, a specific surface area from 50 to 3,200 m.sup.2/g, a thermal conductivity of at least 200 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,000 S/cm per unit of specific gravity. Preferably, the hybrid foam has a density from 0.01 to 1.7 g/cm.sup.3 or an average pore size from 2 nm to 50 nm. In some preferred embodiments, the foam has a specific surface area from 200 to 3,000 m.sup.2/g or a density from 0.1 to 1.2 g/cm.sup.3.
[0035] In certain embodiments, the integral 3D humic acid-carbon hybrid foam contains a content of non-carbon elements in the range of 0.01% to 20% by weight and the non-carbon elements include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen, or boron.
[0036] In some embodiments, the pore walls contain fluorinated humic acid and said foam contains a fluorine content from 0.01% to 15% by weight. In certain other embodiments, the pore walls contain oxidized humic acid and the foam contains an oxygen content from 0.01% to 20% by weight.
[0037] The 3D humic acid-carbon hybrid foam can be in a continuous-length roll sheet form having a thickness from 100 nm to 10 cm and a length of at least 2 meters and may be produced by a roll-to-roll process.
[0038] In some embodiments, the 3D humic acid-carbon hybrid foam has an oxygen content or non-carbon content less than 1% by weight, and said pore walls have an inter-planar spacing less than 0.35 nm, a thermal conductivity of at least 250 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,500 S/cm per unit of specific gravity. Preferably, the hybrid foam has an oxygen content or non-carbon content less than 0.01% by weight and the pore walls contain stacked hexagonal carbon planes having an inter-planar spacing less than 0.34 nm, a thermal conductivity of at least 300 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,000 S/cm per unit of specific gravity.
[0039] Further preferably, the foam has an oxygen content or non-carbon content no greater than 0.01% by weight and the pore walls contain stacked hexagonal carbon planes having an inter-planar spacing less than 0.336 nm, a thermal conductivity of at least 350 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,500 S/cm per unit of specific gravity. Still more preferably, the foam has pore walls containing stacked hexagonal carbon planes having an inter-planar spacing less than 0.336 nm, a thermal conductivity greater than 400 W/mK per unit of specific gravity, and/or an electrical conductivity greater than 4,000 S/cm per unit of specific gravity. In some embodiments, the pore walls contain stacked hexagonal carbon planes having an inter-planar spacing less than 0.337 nm and a mosaic spread value less than 1.0.
[0040] Preferably, the pore walls contain a 3D network of interconnected hexagonal carbon planes, or the foam contains meso-scaled pores having a pore size from 2 nm to 50 nm.
[0041] The present invention also provides an oil-removing or oil-separating device containing the 3D humic acid-carbon hybrid foam as an oil-absorbing element. Also provided is a solvent-removing or solvent-separating device containing the 3D humic acid-carbon hybrid foam of as a solvent-absorbing or solvent-separating element.
[0042] The invention also provides a method to separate oil from water. The method comprises the steps of: (a) providing an oil-absorbing element comprising the integral 3D humic acid-carbon hybrid foam; (b) contacting an oil-water mixture with the element, which absorbs the oil from the mixture; (c) retreating the element from the mixture and extracting the oil from the element; and (d) reusing the element.
[0043] Additionally, the invention provides a method to separate an organic solvent from a solvent-water mixture or from a multiple-solvent mixture. The method comprises the steps of: (a) providing an organic solvent-absorbing or solvent-separating element comprising the integral 3D humic acid-carbon hybrid foam; (b) bringing the element in contact with an organic solvent-water mixture or a multiple-solvent mixture containing a first solvent and at least a second solvent; (c) allowing the element to absorb the organic solvent from the mixture or separate the first solvent from the at least second solvent; (d) retreating the element from the mixture and extracting the organic solvent or first solvent from the element; and (e) reusing the element.
[0045] The present invention provides a method of producing an integral 3D humic acid-carbon hybrid foam. This method is stunningly simple. The method comprises: (A) forming a solid shape of humic acid-polymer particle mixture; and (B) pyrolyzing the solid shape of humic acid-polymer particle mixture to thermally reduce said humic acid into reduced humic acid sheets and, essentially concurrently, thermally convert the polymer into pores and carbon or graphite that bonds reduced humic acid sheets to form the integral 3D humic acid-carbon hybrid foam.
[0046] Preferably, step (A) comprises: (i) dispersing humic acid in water or a solvent to form a suspension and dispersing multiple polymer particles in this suspension to form a slurry; and (ii) dispensing the slurry and removing water or solvent to form a solid shape of humic acid-polymer particle mixture. Such a step enables humic acid molecules or sheets to wrap around polymer particles (fully coated and embraced by humic acid).
[0047] Preferably, the integral 3D humic acid-carbon hybrid foam is in a film, sheet, paper, filament, rod, powder, ingot, or bulk form of essentially any reasonable shape.
[0048] The polymer particles preferably include plastic or rubber beads, pellets, spheres, wires, fibers, filaments, discs, ribbons, or rods, having a diameter or thickness from 10 nm to 10 mm (preferably from 100 nm to 1 mm). In some embodiments, the polymer particles are selected from solid particles of a thermoplastic, thermoset resin, rubber, semi-penetrating network polymer, penetrating network polymer, natural polymer, or a combination thereof.
[0051] In the invented method, the step of pyrolyzing can include carbonizing the polymer particles at a temperature from 200.degree. C. to 2,500.degree. C. to obtain reduced humic acid-carbon foam, or carbonizing the polymer particles at a temperature from 200.degree. C. to 2,500.degree. C. to obtain reduced humic acid-carbon foam and then graphitizing the reduced humic acid-carbon foam from 2,500.degree. C. to 3,200.degree. C. to obtain graphitized humic acid-carbon foam.
[0052] In certain embodiments, the shaping step includes melting the polymer particles to form a polymer melt mixture with humic acid sheets dispersed therein, forming the polymer melt mixture into a desired shape and solidifying the desired shape into a humic acid-polymer composite structure.
[0053] In certain embodiments, the shaping step includes dissolving the polymer particles in a solvent to form a polymer solution mixture with humic acid sheets dispersed therein, forming the polymer solution mixture into a desired shape, and removing the solvent to solidify the desired shape into a humic acid-polymer composite structure.
[0055] In desired embodiments where humic acid molecules or sheets wrap around (fully coat and embrace) the polymer particles, the shaping step includes forming a mass of said graphene-coated or graphene-embedded polymer particles into a compacted object. The compacted object may be in a form selected from a rod, sheet, film, fiber, powder, ingot, or block.
[0056] FIG. 1 A flow chart showing the most commonly used prior art process of producing highly oxidized graphene (NGPs) that entails tedious chemical oxidation/intercalation, rinsing, and high-temperature exfoliation procedures.
[0057] FIG. 2 A flow chart showing the presently invented process for producing integral 3D humic acid-carbon hybrid foam.
[0058] FIG. 3 Schematic of the heat-induced conversion of polymer into carbon, which bonds humic acid sheets together to form a 3D HA-carbon hybrid foam. The compacted structure of humic acid-coated polymer particles is converted into a highly porous structure.
[0059] FIG. 4(A) Thermal conductivity values vs. specific gravity of a 3D integral HA-carbon foam produced by the presently invented process, a meso-phase pitch-derived graphite foam, and a Ni foam-template assisted CVD graphene foam.
[0061] FIG. 5 Thermal conductivity values of 3D HA-carbon hybrid foam and pristine graphene foam (prepared by casting with a blowing agent and then heat treating) plotted as a function of the final (maximum) heat treatment temperature.
[0063] FIG. 7 The amount of oil absorbed per gram of integral 3D HA-carbon hybrid foam, plotted as a function of the oxygen content in the foam having a porosity level of approximately 98% (oil separation from oil-water mixture).
[0064] FIG. 8 The amount of oil absorbed per gram of integral 3D HA-carbon hybrid foam, plotted as a function of the porosity level (given the same oxygen content).
[0065] FIG. 9 The amount of chloroform absorbed out of a chloroform-water mixture, plotted as a function of the degree of fluorination.
[0067] Humic acid (HA) is an organic matter commonly found in soil and can be extracted from the soil using a base (e.g. KOH). HA can also be extracted from a type of coal called leonardite, which is a highly oxidized version of lignite coal. HA extracted from leonardite contains a number of oxygenated groups (e.g. carboxyl groups) located around the edges of the graphene-like molecular center (S1.sup.32 core of hexagonal carbon structure). This material is slightly similar to graphene oxide (GO) which is produced by strong acid oxidation of natural graphite. HA has a typical oxygen content of 5% to 42% by weight (other major elements being carbon, hydrogen, and nitrogen). Example of a typical humic acid, having a variety of components including quinone, phenol, catechol and sugar moieties, is given in Scheme 1 below (source: Stevenson F. J. "Humus Chemistry: Genesis, Composition, Reactions," John Wiley & Sons, New York 1994).
[0068] The present invention provides an integral 3D humic acid-carbon hybrid foam and a method of producing such a hybrid foam. This method is stunningly simple, but effective, of low cost, and environmentally benign. As schematically illustrated in FIG. 2, the method comprises: (A) forming a solid shape of humic acid-polymer particle mixture; and (B) pyrolyzing the solid shape of humic acid-polymer particle mixture to thermally reduce humic acid into reduced humic acid sheets and, essentially concurrently, thermally convert the polymer into pores and carbon or graphite that bonds reduced humic acid sheets to form the integral 3D humic acid-carbon hybrid foam.
[0069] Preferably, step (A) comprises: (i) dispersing humic acid in water or a solvent to form a suspension (or solution) and dispersing multiple polymer particles in this suspension or solution to form a slurry; and (ii) dispensing the slurry and removing water or solvent to form a solid shape of humic acid-polymer particle mixture. Such a step enables humic acid molecules or sheets to wrap around polymer particles (polymer particles being fully coated and embraced by humic acid). Humic acid (HA) is readily dissolved in water and a wide variety of polar solvents, such as methanol and ethanol.
[0070] Preferably, upon heat treatments, the solid shape is transformed into an integral 3D humic acid-carbon hybrid foam, which can be in a film, sheet, paper, filament, rod, powder, ingot, or bulk form of essentially any desired shape.
[0071] The method can include forming humic acid-embraced particles into a desired shape of humic acid-polymer composite structure. This forming step can be as simple as a compacting step that just mechanically packs humic acid-coated or embedded polymer particles into a desired shape. Alternatively, this forming step can entail melting the polymer particles to form a polymer matrix with humic acid molecules or sheets dispersed therein. Such a humic acid-polymer structure can be in any practical shape or dimensions (fiber, rod, plate, cylinder, or any regular shape or odd shape).
[0072] The humic acid-polymer compact or composite structure is then pyrolyzed to thermally reduce humic acid into reduced humic acid (RHA) and, concurrently, thermally convert the polymer into carbon or graphite that bonds the reduced humic acid sheets together to form the integral 3D RHA-carbon hybrid foam. The non-carbon content of RHA can be varied between approximately 0.01% by weight and 5% by weight, depending upon the maximum heat treatment temperature involved.
[0075] These polymers (both high and low carbon yields), when heated at a temperature of 300-2,500.degree. C., are converted into a carbon material, which is preferentially nucleated near humic acid (HA) sheet edges. Such a carbon material naturally bridges the gaps between HA sheets, forming interconnected electron-conducting pathways. In actuality, the resulting HA-carbon hybrid foam is composed of integral 3D network of carbon-bonded HA sheets, enabling continuous transport of electrons and phonons (quantized lattice vibrations) between HA sheets or domains without interruptions. When further heated at a temperature higher than 2,500.degree. C., the carbon phase can get graphitized to further increase both the electric conductivity and thermal conductivity. The amount of non-carbon elements is also decreased to typically below 1% by weight (down to 0.01%) if the graphitization time exceeds 1 hour.
[0076] It may be noted that an organic polymer typically contains a significant amount of non-carbon elements, which can be reduced or eliminated via heat treatments. As such, pyrolyzation of a polymer causes the formation and evolution of volatile gas molecules, such as CO.sub.2 and H.sub.2O, which lead to the formation of pores in the resulting polymeric carbon phase. However, such pores also have a high tendency to get collapsed if the polymer is not constrained when being carbonized (the carbon structure can shrink while non-carbon elements are being released). We have surprising discovered that the humic acid sheets wrapped around a polymer particle are capable of constraining the carbon pore walls from being collapsed. In the meantime, some carbon species also permeate to the gaps between humic acid sheets where these species bond the humic acid sheets together. The pore sizes and pore volume (porosity level) of the resulting 3D integral humic acid-carbon foam mainly depend upon the starting polymer size and the carbon yield of the polymer.
[0077] It may be further noted that a certain desired degree of hydrophilicity can be imparted to the pore walls of the humic acid -carbon hybrid foam if the non-carbon element content (H and O) is from 2 to 20% by weight. These features enable separation of oil from water by selectively absorbing oil from an oil-water mixture. In other words, such a HA-carbon hybrid foam material is capable of recovering oil from water, helping to clean up oil-spilled river, lake, or ocean. The oil absorption capacity is typically from 50% to 500% of the foam's own weight. This is a wonderfully useful material for environmental protection purposes.
[0079] It may be noted that the HA-carbon foam may be subjected to compression during and/or after the graphitization treatment. This operation enables us to adjust the graphene sheet orientation and the degree of porosity.
[0080] In order to characterize the structure of the graphitic materials produced, X-ray diffraction patterns were obtained with an X-ray diffractometer equipped with CuKcv radiation. The shift and broadening of diffraction peaks were calibrated using a silicon powder standard. The degree of graphitization, g, was calculated from the X-ray pattern using the Mering's Eq, d.sub.002=0.3354 g+0.344 (1-g), where d.sub.002 is the interlayer spacing of graphite or graphene crystal in nm. This equation is valid only when d.sub.002 is equal or less than approximately 0.3440 nm. In the present study, the graphene-like (HA or RHA) foam walls having a d.sub.002 higher than 0.3440 nm reflects the presence of oxygen-containing functional groups (such as --OH, >O, and --COOH on graphene molecular plane surfaces or edges) that act as a spacer to increase the inter-graphene spacing.
[0081] Another structural index that can be used to characterize the degree of ordering of the stacked and bonded RHA planes in the foam walls of graphene and conventional graphite crystals is the "mosaic spread," which is expressed by the full width at half maximum of a rocking curve (X-ray diffraction intensity) of the (002) or (004) reflection. This degree of ordering characterizes the graphite or graphene crystal size (or grain size), amounts of grain boundaries and other defects, and the degree of preferred grain orientation. A nearly perfect single crystal of graphite is characterized by having a mosaic spread value of 0.2-0.4. Most of our RHA walls have a mosaic spread value in this range of 0.2-0.4 (if produced with a heat treatment temperature (HTT) no less than 2,500.degree. C.). However, some values are in the range of 0.4-0.7 if the HTT is between 1,500 and 2,500.degree. C., and in the range of 0.7-1.0 if the HTT is between 300 and 1,500.degree. C.
[0082] In-depth studies using a combination of SEM, TEM, selected area diffraction , X-ray diffraction, AFM, Raman spectroscopy, and FTIR indicate that the humic acid-carbon foam walls are composed of several large graphene planes (with length/width typically >>20 nm, more typically >>100 nm, often >>1.mu.m, and, in many cases, >>10 .mu.m). This is quite unexpected since the lateral dimensions (length and width) of original humic acid sheets or molecules, prior to being heat treated, are typically <20 nm and more typically <10 nm. This implies that a plurality of HA sheets or molecules can be merged edge to edge through covalent bonds with one another, into a larger (longer or wider) sheet.
[0083] These large graphene-like planes also can be stacked and bonded along the thickness direction (crystallographic c-axis direction) often through not just the van der Waals forces (as in conventional graphite crystallites), but also covalent bonds, if the final heat treatment temperature is lower than 2,500.degree. C. In these cases, wishing not to be limited by theory, but Raman and FTIR spectroscopy studies appear to indicate the co-existence of sp.sup.2 (dominating) and sp.sup.3 (weak but existing) electronic configurations, not just the conventional sp.sup.2 in graphite.
[0084] The integral 3D HA-carbon hybrid foam is composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer HA sheets chemically bonded by a carbon material having a carbon material-to-HA weight ratio from 1/100 to 1/2, wherein the few-layer HA sheets have 2-10 layers of stacked graphene-like HA planes having an inter-plane spacing 4.sub.002 from 0.3354 nm to 0.36 nm as measured by X-ray diffraction and the single-layer or few-layer graphene-like HA sheets contain 0.01% to 25% by weight of non-carbon elements (more typically <15%). A plurality of single-layer or few-layer HA sheets embracing the underlying polymer particles can overlap with one another to form a stack of graphene-like sheets. The stack can have a thickness greater than 5 nm and, in some cases, greater than 10 nm.
[0085] The integral 3D HA-carbon hybrid foam typically has a density from 0.001 to 1.7 g/cm.sup.3, a specific surface area from 50 to 3,000 m.sup.2/g, a thermal conductivity of at least 200 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,000 S/cm per unit of specific gravity. In a preferred embodiment, the pore walls contain stacked graphene-like RHA planes having an inter-planar spacing d.sub.002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction.
[0086] Many of the HA sheets can be merged edge to edge through covalent bonds with one another, into an integrated RHA entity. The gaps between the free ends of those unmerged sheets or shorter merged sheets are bonded by the carbon phase converted from the polymer particles. Due to these unique chemical composition (including oxygen or hydrogen content, etc.), morphology, crystal structure (including inter-planar spacing), and structural features (e.g. degree of orientations, few defects, chemical bonding and no gap between graphene-like sheets, and substantially no interruptions along graphene plane directions), the HA-carbon hybrid foam has a unique combination of outstanding thermal conductivity, electrical conductivity, mechanical strength, and stiffness (elastic modulus).
[0087] The aforementioned features and characteristics make the integral 3D HA-carbon hybrid foam an ideal element for a broad array of engineering and biomedical applications. For instance, for thermal management purposes alone, the graphene-carbon foam can be used in the following applications: [0088] a) The HA-carbon hybrid foam, being compressible and of high thermal conductivity, is ideally suited for use as a thermal interface material (TIM) that can be implemented between a heat source and a heat spreader or between a heat source and a heat sink. [0089] b) The hybrid foam can be used as a heat spreader per se due to its high thermal conductivity. [0090] c) The hybrid foam can be used as a heat sink or heat dissipating material due to his high heat-spreading capability (high thermal conductivity) and high heat-dissipating capability (large number of surface pores inducing massive air-convection micro or nano channels). [0091] d) The light weight (low density adjustable between 0.001 and 1.8 g/cm.sup.3), high thermal conductivity per unit specific gravity or per unit of physical density, and high structural integrity (HA sheets being bonded by carbon) make this hybrid foam an ideal material for a durable heat exchanger.
[0093] A heat exchanger is a device used to transfer heat between one or more fluids; e.g. a gas and a liquid separately flowing in different channels. The fluids are typically separated by a solid wall to prevent mixing. The presently invented graphene-carbon hybrid foam material is an ideal material for such a wall provided the foam is not a totally open-cell foam that allows for mixing of fluids. The presently invented method enables production of both open-cell and closed-cell foam structures. The high surface pore areas enable dramatically faster exchange of heats between the two or multiple fluids.
[0094] Heat exchangers are widely used in refrigeration systems, air conditioning units, heaters, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, and sewage treatment. A well-known example of a heat exchanger is found in an internal combustion engine in which a circulating engine coolant flows through radiator coils while air flows past the coils, which cools the coolant and heats the incoming air. The solid walls (e.g. that constitute the radiator coils) are normally made of a high thermal conductivity material, such as Cu and Al. The presently invented HA-carbon foam having either a higher thermal conductivity or higher specific surface area is a superior alternative to Cu and Al, for instance.
[0095] There are many types of heat exchangers that are commercially available: shell and tube heat exchanger, plate heat exchangers, plate and shell heat exchanger, adiabatic wheel heat exchanger, plate fin heat exchanger, pillow plate heat exchanger, fluid heat exchangers, waste heat recovery units, dynamic scraped surface heat exchanger, phase-change heat exchangers, direct contact heat exchangers, and microchannel heat exchangers. Every one of these types of heat exchangers can take advantage of the exceptional high thermal conductivity and specific surface area of the presently invented foam material.
[0096] The presently invented solid HA-carbon foam can also be used in a heat sink. Heat sinks are widely used in electronic devices for heat dissipation purposes. The central processing unit (CPU) and battery in a portable microelectronic device (such as a notebook computer, tablet, and smart phone) are well-known heat sources. Typically, a metal or graphite object (e.g. Cu foil or graphite foil) is brought into contact with the hot surface and this object helps to spread the heat to an external surface or outside air (primarily by conduction and convection and to a lesser extent by radiation).. In most cases, a thin thermal interface material (TIM) mediates between the hot surface of the heat source and a heat spreader or a heat-spreading surface of a heat sink. (The presently invented HA-carbon foam can also be used as a TIM.)
[0097] A heat sink usually consists of a high-conductivity material structure with one or more flat surfaces to ensure good thermal contact with the components to be cooled, and an array of comb or fin like protrusions to increase the surface contact with the air, and thus the rate of heat dissipation. A heat sink may be used in conjunction with a fan to increase the rate of airflow over the heat sink. A heat sink can have multiple fins (extended or protruded surfaces) to improve heat transfer. In electronic devices with limited amount of space, the shape/arrangement of fins must be optimized such that the heat transfer density is maximized. Alternatively or additionally, cavities (inverted fins) may be embedded in the regions formed between adjacent fins. These cavities are effective in extracting heat from a variety of heat generating bodies to a heat sink.
[0098] Typically, an integrated heat sink comprises a heat collection member (core or base) and at least one heat dissipation member (e.g. a fin or multiple fins) integral to the heat collection member (base) to form a finned heat sink. The fins and the core are naturally connected or integrated together into a unified body without using an externally applied adhesive or mechanical fastening means to connect the fins to the core. The heat collection base has a surface in thermal contact with a heat source (e.g. a LED), collects heat from this heat source, and dissipates heat through the fins into the air.
[0099] As illustrative examples, FIG. 10 provides a schematic of two heat sinks: 300 and 302. The first one contains a heat collection member (or base member) 304 and multiple fins or heat dissipation members (e.g. fin 306) connected to the base member 304. The base member 304 is shown to have a heat collection surface 314 intended to be in thermal contact with a heat source. The heat dissipation member or fin 306 is shown to have at least a heat dissipation surface 320.
[0100] A particularly useful embodiment is an integrated radial heat sink 302 comprising a radial finned heat sink assembly that comprises: (a) a base 308 comprising a heat collection surface 318; and (b) a plurality of spaced parallel planar fin members (e.g. 310, 312 as two examples) supported by or integral with the base 308, wherein the planar fin members (e.g. 310) comprise the at least one heat dissipation surface 322. Multiple parallel planar fin members are preferably equally spaced.
[0101] The presently invented HA-carbon hybrid foam, being highly elastic and resilient, is itself a good thermal interface material and a highly effective heat spreading element as well. In addition, this high-conductivity foam can also be used as an inserts for electronic cooling and for enhancing the heat removal from small chips to a heat sink. Because the space occupied by high conductivity materials is a major concern, it is a more efficient design to make use of high conductivity pathways that can be embedded into a heat generating body. The elastic and highly conducting solid graphene foam herein disclosed meets these requirements perfectly.
[0102] The high elasticity and high thermal conductivity make the presently invented solid HA-carbon hybrid foam a good conductive thick plate to be placed as a heat transfer interface between a heat source and a cold flowing fluid (or any other heat sink) to improve the cooling performance. In such arrangement, the heat source is cooled under the thick HA-carbon foam plate instead of being cooled in direct contact with the cooling fluid. The thick plate of HA-carbon foam can significantly improve the heat transfer between the heat source and the cooling fluid by way of conducting the heat current in an optimal manner. No additional pumping power and no extra heat transfer surface area are required.
[0103] The solid HA-carbon foam is also an outstanding material to construct a heat pipe. A heat pipe is a heat transfer device that uses evaporation and condensation of a two-phase working fluid or coolant to transport large quantities of heat with a very small difference in temperature between the hot and cold interfaces. A conventional heat pipe consists of sealed hollow tube made of a thermally conductive metal such as Cu or Al, and a wick to return the working fluid from the evaporator to the condenser. The pipe contains both saturated liquid and vapor of a working fluid (such as water, methanol or ammonia), all other gases being excluded. However, both Cu and Al are prone to oxidation or corrosion and, hence, their performance degrades relatively fast over time. In contrast, the solid HA-carbon foam is chemically inert and does not have these oxidation or corrosion issues. The heat pipe for electronics thermal management can have a solid graphene foam envelope and wick, with water as the working fluid. HA-carbon/methanol may be used if the heat pipe needs to operate below the freezing point of water, and HA-carbon/ammonia heat pipes may be used for electronics cooling in space.
[0104] Peltier cooling plates operate on the Peltier effect to create a heat flux between the junction of two different conductors of electricity by applying an electric current. This effect is commonly used for cooling electronic components and small instruments. In practice, many such junctions may be arranged in series to increase the effect to the amount of heating or cooling required. The solid graphene foam may be used to improve the heat transfer efficiency.
[0105] The solid HA-carbon foam can be made to contain microscopic pores (<2 nm) or meso-scaled pores having a pore size from 2 nm to 50 nm. The solid HA-carbon hybrid foam can also be made to contain micron-scaled pores (1-500 .mu.m). Based on well-controlled pore size alone, the instant HA-carbon foam can be an exceptional filter material for air or water filtration.
[0106] Further, the humic acid (HA) pore wall chemistry and carbon phase chemistry can be independently controlled to impart different amounts and/or types of functional groups to either or both of the HA sheets and the carbon binder phase (e.g. as reflected by the percentage of O, F, N, H, etc. in the foam). In other words, the concurrent or independent control of both pore sizes and chemical functional groups at different sites of the internal structure provide unprecedented flexibility or highest degree of freedom in designing and making HA-carbon hybrid foams that exhibit many unexpected properties, synergistic effects, and some unique combination of properties that are normally considered mutually exclusive (e.g. some part of the structure is hydrophobic and other part hydrophilic; or the foam structure is both hydrophobic and oleophilic). A surface or a material is said to be hydrophobic if water is repelled from this material or surface and that a droplet of water placed on a hydrophobic surface or material will form a large contact angle. A surface or a material is said to be oleophilic if it has a strong affinity for oils and not for water. The present method allows for precise control over hydrophobicity, hydrophilicity, and oleophilicity.
[0107] The present invention also provides an oil-removing, oil-separating, or oil-recovering device, which contains the presently invented 3D HA-carbon hybrid foam as an oil-absorbing or oil-separating element. Also provided is a solvent-removing or solvent-separating device containing the 3D HA-carbon hybrid foam as a solvent-absorbing element.
[0108] A major advantage of using the instant HA-carbon hybrid foam as an oil-absorbing element is its structural integrity. Due to the notion that HA sheets are chemically bonded by the carbon material, the resulting foam would not get disintegrated upon repeated oil absorption operations. In contrast, we have discovered that graphene-based oil-absorbing elements prepared by hydrothermal reduction, vacuum-assisted filtration, or freeze-drying get disintegrated after absorbing oil for 2 or 3 times. There is just nothing (other than weak van der Waals forces existing prior to first contact with oil) to hold these otherwise separated graphene sheets together. Once these graphene sheets are wetted by oil, they no longer are able to return to the original shape of the oil-absorbing element.
[0109] Another major advantage of the instant technology is the flexibility in designing and making oil-absorbing elements that are capable of absorbing oil up to an amount as high as 400 times of its own weight yet still maintaining its structural shape (without significant expansion). This amount depends upon the specific pore volume of the foam, which can be controlled mainly by the ratio between the amount of original carrier polymer particles and the amount of HA molecules or sheets prior to the heat treatment.
[0110] The invention also provides a method to separate/recover oil from an oil-water mixture (e.g. oil-spilled water or waste water from oil sand). The method comprises the steps of (a) providing an oil-absorbing element comprising an integral HA-carbon hybrid foam; (b) contacting an oil-water mixture with the element, which absorbs the oil from the mixture; and (c) retreating the oil-absorbing element from the mixture and extracting the oil from the element. Preferably, the method comprises a further step of (d) reusing the element.
[0111] Additionally, the invention provides a method to separate an organic solvent from a solvent-water mixture or from a multiple-solvent mixture. The method comprises the steps of (a) providing an organic solvent-absorbing element comprising an integral HA-carbon hybrid foam; (b) bringing the element in contact with an organic solvent-water mixture or a multiple-solvent mixture containing a first solvent and at least a second solvent; (c) allowing this element to absorb the organic solvent from the mixture or absorb the first solvent from the at least second solvent; and (d) retreating the element from the mixture and extracting the organic solvent or first solvent from the element. Preferably, the method contains an additional step (e) of reusing the solvent-absorbing element.
[0112] The following examples are used to illustrate some specific details about the best modes of practicing the instant invention and should not be construed as limiting the scope of the invention.
[0113] One experiment entails dispersing 5% by weight of PP powder in a humic acid-water solution (5% HA) to obtain a slurry. The slurry was then spray-dried to form powder of HA-coated PP particles. The HA-coated PP particles were then compacted in a mold cavity to form a green compact, which was then heat-treated in a sealed crucible at 350.degree. C. and then at 600.degree. C. for 2 hours to produce an integral HA-carbon hybrid foam.
[0114] Although polypropylene (PP) is herein used as an example, the solid polymer particles for HA-carbon hybrid foam production are not limited to PP. It could be any polymer (thermoplastic, thermoset, rubber, wax, mastic, gum, organic resin, etc.) provided the polymer can be made into a particulate form (fine powder particles having a diameter preferably in the range of 10 nm-10 .mu.m, further preferably 20 nm-1 .mu.m). It may be noted that un-cured or partially cured thermosetting resins (such as epoxide and imide-based oligomers or rubber) can be made into a particle form at room temperature or lower (e.g. cryogenic temperature). Hence, even partially cured thermosetting resin particles can be used as solid polymer particles.
[0115] In an experiment, 100 grams of ABS powder, as solid polymer particles, were mixed into a humic acid-ethanol solution to form a slurry. The slurry was cast on a glass surface to form HA-polymer films (20-200 .mu.m thick), which were then carbonized to prepare HA-carbon foam samples under different temperature and compression conditions.
[0116] In one example, PAN fiber segments (2 mm long as the polymer particles) were dispersed in a HA-methanol solution to form a slurry, which was oven dried to form a mass of HA-coated PAN fiber powder. The HA-coated PAN fibers were then compacted and melted together to form several composite films. The films were subjected to heat treatments at 250.degree. C. for 1 hour (in room air), 350.degree. C. for 2 hours, and 1,000.degree. C. for 2 hours (under an argon gas atmosphere) to obtain RHA-carbon foam layers. Half of the carbonized foam layers were then heated to 2,850.degree. C. and maintained at this temperature for 0.5 hours to obtain graphitized RHA-carbon foam.
[0117] Particles of cured phenolic resin were dispersed in a HA-water suspension to form a slurry, which was spray-dried to form a slurry. A mass of HA-coated resin particles was compressed to form a green compact, which was then infiltrated with a small amount of petroleum pitch. Separately, another green compact of HA-coated resin particles was prepared under comparable conditions, but no pitch infiltration was attempted. The two compacts were then subjected to identical pyrolysis treatments.
[0118] Slurry coating and drying was used to prepare HA-coated polymer particles. Subsequently, a mass of HA-coated PE pellets and a mass of HA-coated nylon beads were separately compacted in a mold cavity and briefly heated above the melting point of PE or nylon and then rapidly cooled to form two green compacts. For comparison purposes, two corresponding compacts were prepared from a mass of un-coated PE pellets and a mass of un-coated nylon beads. These 4 compacts were then subjected to pyrolyzation (by heating the compacts in a chamber from 100.degree. C. to 650.degree. C.). The results were very surprising. The compacts of HA-coated polymer particles were found to be converted to graphene-carbon hybrid foam structures having dimensions comparable to the dimensions of the original compacts (3 cm.times.3 cm.times.0.5 cm). SEM examination of these structures indicates that carbon phases are present near the edges of HA sheets and these carbon phases act to bond the HA sheets together. The carbon-bonded HA sheets form a skeleton of HA-carbon hybrid pore walls having pores being present in what used to be the space occupied by the original polymer particles, as schematically illustrated in FIG. 3.
[0119] In contrast, the two compacts from un-coated pellets or beads shrank to become essentially two solid masses of carbon having a volume approximately 15%-20% of the original compact volumes. These highly shrunk solid masses are practically pore-free carbon materials; they are not a foam material.
[0120] The experiment began with preparation of `Theron-sized rubber particles. A mixture of methylhvdro dimethyl-siloxane polymer (20 g) and polydimethylsiloxane, vinyldimethyl terminated polymer (30 g) was obtained by using a homogenizer under ambient conditions for 1 minute. Tween 80 (4.6 g) was added and the mixture was homogenized for 20 seconds. Platinum-divinyttetramethyldisiloxane complex (0.5 gin 15 g methanol) was added and mixed for 10 seconds. This mixture was added to 350 g of distilled water and a stable latex was obtained by homogenization for 15 minutes. The latex was heated to 60.degree. C. for 15 hours. The latex was then de-emulsified with anhydrous sodium sulfate (2.0 g) and the silicone rubber particles were obtained by filtration under a vacuum, washing with distilled water, and drying under vacuum at 25.degree. C. The particle size distribution of the resulting rubber particles was 3-11 .mu.m.
[0121] Humic acid-coated rubber particles were obtained by spray-drying of HA-water-rubber slurry. The HA-coated rubber particles were then mixed with 5% by wt. of petroleum pitch (as a binder) and mechanically compacted together to form several composite sheets. The composite sheets were then subjected to heat treatments at 350.degree. C. for 1 hour, 650.degree. C. for 2 hours, and 1,000.degree. C. for 1 hour in a tube furnace to obtain HA-carbon foam layers.
[0122] In a typical procedure, a sheet of HA-carbon hybrid was fluorinated by vapors of chlorine trifluoride in a sealed autoclave reactor to yield fluorinated HA-carbon hybrid film. Different durations of fluorination time were allowed for achieving different degrees of fluorination. Sheets of fluorinated HA-carbon foam were then separately immersed in containers each containing a chloroform-water mixture. We observed that these foam sheets selectively absorb chloroform from water and the amount of chloroform absorbed increases with the degree of fluorination until the fluorine content reaches 7.2% by wt. (FIG. 9).
[0123] Several pieces of HA-carbon foam prepared in Example 3 were immersed in a 30% H.sub.2O.sub.2-water solution for a period of 2-48 hours to obtain oxidized HA-carbon foams, having a controlled oxygen content of 2-25% by weight.
[0124] Some oxidized HA-carbon foam samples were mixed with different proportions of urea and the mixtures were heated in a microwave reactor (900 W) for 0.5 to 5 minutes. The products were washed several times with deionized water and vacuum dried. The products obtained were nitrogenated HA-carbon foam. The nitrogen contents were from 3% to 17.5 wt. %, as measured by elemental analysis.
[0125] It may be noted that different functionalization treatments of the HA-carbon hybrid foam were for different purposes. For instance, oxidized HA-carbon hybrid foam structures are particularly effective as an absorber of oil from an oil-water mixture (i.e. oil spilled on water and then mixed together). In this case, the integral 3D HA (0-15% by wt. oxygen)-carbon foam structures are both hydrophobic and oleophilic (FIG. 7 and FIG. 8). A surface or a material is said to be hydrophobic if water is repelled from this material or surface and that a droplet of water placed on a hydrophobic surface or material will form a large contact angle. A surface or a material is said to be oleophilic if it has a strong affinity for oils and not for water.
[0126] Different contents of 0, F, and/or N also enable the presently invented HA-carbon hybrid foams to absorb different organic solvents from water, or to separate one organic solvent from a mixture of multiple solvents.
[0127] Graphite oxide as prepared by oxidation of graphite flakes with sulfuric acid, nitrate, and permanganate according to the method of Hummers [U.S. Pat. No. 2,798,878, Jul. 9, 1957]. Upon completion of the reaction, the mixture was poured into deionized water and filtered. The graphite oxide was repeatedly washed in a 5% solution of HCl to remove most of the sulphate ions. The sample was then washed repeatedly with deionized water until the pH of the filtrate was neutral. The slurry was spray-dried and stored in a vacuum oven at 60.degree. C. for 24 hours. The interlayer spacing of the resulting laminar graphite oxide was determined by the Debey-Scherrer X-ray technique to be approximately 0.73nm (7.3 A). A sample of this material was subsequently transferred to a furnace pre-set at 650.degree. C. for 4 minutes for exfoliation and heated in an inert atmosphere furnace at 1200.degree. C. for 4 hours to create a low density powder comprised of few-layer reduced graphene oxide (RGO). Surface area was measured via nitrogen adsorption BET. This powder was subsequently dry mixed at a 1%-25% loading level with ABS, PE, PP, and nylon pellets, respectively, and compounded using a 25mm twin screw extruder to form composite sheets. These composite sheets were then pyrolyzed.
[0128] Meso-carbon microbeads (MCMBs) were supplied from China Steel Chemical Co., Kaohsiung, Taiwan. This material has a density of about 2.24 g/cm.sup.3 with a median particle size of about 16 .mu.m. MCMB (10 grams) were intercalated with an acid solution (sulfuric acid, nitric acid, and potassium permanganate at a ratio of 4:1:0.05) for 48-96 hours. Upon completion of the reaction, the mixture was poured into deionized water and filtered. The intercalated MCMBs were repeatedly washed in a 5% solution of HCl to remove most of the sulphate ions. The sample was then washed repeatedly with deionized water until the pH of the filtrate was no less than 4.5. The slurry was then subjected ultrasonication for 10-100 minutes to produce GO suspensions. TEM and atomic force microscopic studies indicate that most of the GO sheets were single-layer graphene when the oxidation treatment exceeded 72 hours, and 2- or 3-layer graphene when the oxidation time was from 48 to 72 hours.
[0129] The GO sheets contain oxygen proportion of approximately 35%-47% by weight for oxidation treatment times of 48-96 hours. GO sheets were suspended in water. Baking soda (5-20% by weight), as a chemical blowing agent, was added to the suspension just prior to casting. The suspension was then cast onto a glass surface. Several samples were cast, some containing a blowing agent and some not. The resulting GO films, after removal of liquid, have a thickness that can be varied from approximately 10 to 500 p.m. Several sheets of the GO film, with or without a blowing agent, were then subjected to heat treatments that involve a heat temperature of 80-500.degree. C. for 1-5 hours, which generated a graphene foam structure.
[0130] Recognizing the possibility of the high defect population in GO sheets acting to reduce the conductivity of individual graphene plane, we decided to study if the use of pristine graphene sheets (non-oxidized and oxygen-free, non-halogenated and halogen-free, etc.) can lead to a graphene foam having a higher thermal conductivity. Pristine graphene sheets were produced by using the direct ultrasonication process (also known as the liquid-phase exfoliation in the art).
[0131] In a typical procedure, five grams of graphite flakes, ground to approximately 20 .mu.m or less in sizes, were dispersed in 1,000 mL of deionized water (containing 0.1% by weight of a dispersing agent, Zonyl.RTM. FSO from DuPont) to obtain a suspension. An ultrasonic energy level of 85 W (Branson S450 Ultrasonicator) was used for exfoliation, separation, and size reduction of graphene sheets for a period of 15 minutes to 2 hours. The resulting graphene sheets are pristine graphene that have never been oxidized and are oxygen-free and relatively defect-free. There are no other non-carbon elements.
[0132] Various amounts (1%-30% by weight relative to graphene material) of chemical bowing agents (N, N-Dinitroso pentamethylene tetramine or 4.4`-Oxybis (benzenesulfonyl hydrazide) were added to a suspension containing pristine graphene sheets and a surfactant. The suspension was then cast onto a glass surface. Several samples were cast, including one that was made using CO.sub.2 as a physical blowing agent introduced into the suspension just prior to casting. The resulting graphene films, after removal of liquid, have a thickness that can be varied from approximately 10 to 100 .mu.m. The graphene films were then subjected to heat treatments at a temperature of 80-1,500.degree. C. for 1-5 hours, which generated a graphene foam.
[0133] The procedure was adapted from that disclosed in open literature: Chen, Z. et al. "Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapor deposition," Nat. Mater. 10, 424-428 (2011). Nickel foam, a porous structure with an interconnected 3D scaffold of nickel was chosen as a template for the growth of graphene foam. Briefly, carbon was introduced into a nickel foam by decomposing CH.sub.4 at 1,000.degree. C. under ambient pressure, and graphene films were then deposited on the surface of the nickel foam. Due to the difference in the thermal expansion coefficients between nickel and graphene, ripples and wrinkles were formed on the graphene films. In order to recover (separate) graphene foam, Ni frame must be etched away. Before etching away the nickel skeleton by a hot HCl (or FeCl.sub.3) solution, a thin layer of poly(methyl methacrylate) (PMMA) was deposited on the surface of the graphene films as a support to prevent the graphene network from collapsing during nickel etching. After the PMMA layer was carefully removed by hot acetone, a fragile graphene foam sample was obtained. The use of the PMMA support layer is critical to preparing a free-standing film of graphene foam; only a severely distorted and deformed graphene foam sample was obtained without the PMMA support layer. This is a tedious process that is not environmentally benign and is not scalable.
[0134] Pitch powder, granules, or pellets are placed in a aluminum mold with the desired final shape of the foam. Mitsubishi ARA-24 meso-phase pitch was utilized. The sample is evacuated to less than 1 torr and then heated to a temperature approximately 300.degree. C. At this point, the vacuum was released to a nitrogen blanket and then a pressure of up to 1,000 psi was applied. The temperature of the system was then raised to 800.degree. C. This was performed at a rate of 2 degree C./min. The temperature was held for at least 15 minutes to achieve a soak and then the furnace power was turned off and cooled to room temperature at a rate of approximately 1.5 degree C./min with release of pressure at a rate of approximately 2 psi/min. Final foam temperatures were 630.degree. C. and 800.degree. C. During the cooling cycle, pressure is released gradually to atmospheric conditions. The foam was then heat treated to 1050.degree. C. (carbonized) under a nitrogen blanket and then heat treated in separate runs in a graphite crucible to 2500.degree. C. and 2800.degree. C. (graphitized) in Argon.
[0135] For comparison, a self-assembled graphene hydrogel (SGH) sample was prepared by a one-step hydrothermal method. In a typical procedure, the SGH can be easily prepared by heating 2 mg/mL of homogeneous graphene oxide (GO) aqueous dispersion sealed in a Teflon-lined autoclave at 180.degree. C. for 12 h. The SGH containing about 2.6% (by weight) graphene sheets and 97.4% water has an electrical conductivity of approximately 5.times.10.sup.-3 S/cm. Upon drying and heat treating at 1,500.degree. C., the resulting graphene foam exhibits an electrical conductivity of approximately 1.5.times.10.sup.-1 S/cm, which is 2 times lower than those of the presently invented graphene foams produced by heat treating at the same temperature.
[0136] Samples from various conventional carbon or graphene foam materials were machined into specimens for measuring the thermal conductivity. The bulk thermal conductivity of meso-phase pitch-derived foam ranged from 67 W/mK to 151 W/mK. The density of the samples was from 0.31-0.61 g/cm.sup.3. When weight is taken into account, the specific thermal conductivity of the pitch derived foam is approximately 67/0.31=216 and 151/0.61=247.5 W/mK per specific gravity (or per physical density).
[0137] The compression strength of the samples having an average density of 0.51 g/cm.sup.3 was measured to be 3.6 MPa and the compression modulus was measured to be 74 MPa. By contrast, the compression strength and compressive modulus of the presently invented RHA-carbon foam samples having a comparable physical density are 6.1 MPa and 110 MPa, respectively.
[0138] Shown in FIG. 4(A) are the thermal conductivity values vs. specific gravity of the 3D HA-carbon foam, meso-phase pitch-derived graphite foam, and Ni foam template-assisted CVD graphene foam. These data clearly demonstrate the following unexpected results: [0139] 1) The 3D integral HA-carbon foams produced by the presently invented process exhibit significantly higher thermal conductivity as compared to both meso-phase pitch-derived graphite foam and Ni foam template-assisted CVD graphene, given the same physical density. [0140] 2) This is quite surprising in view of the notion that CVD graphene is essentially pristine graphene that has never been exposed to oxidation and should have exhibited a high thermal conductivity compared to our HA-carbon hybrid foam. The carbon phase of the hybrid foam is in general of low degree of crystallinity (some being amorphous carbon) and, thus, has much lower thermal or electrical conductivity as compared with graphene alone. However, when the carbon phase is coupled with RHA sheets to form an integral structure produced by the presently invented method, the resulting hybrid foam exhibits a higher thermal conductivity as compared to an all-pristine graphene foam. These exceptionally high thermal conductivity values observed with the RHA-carbon hybrid foams herein produced are much to our surprise. This is likely due to the observation that the otherwise isolated RHA sheets are now bonded by a carbon phase, providing a bridge for the uninterrupted transport of electrons and phonons. [0141] 3) The specific conductivity of the presently invented hybrid foam materials exhibits values from 250 to 500 W/mK per unit of specific gravity; but those of other types of foam materials are typically lower than 250 W/mK per unit of specific gravity. [0142] 4) Summarized in FIG.5 are thermal conductivity data for a series of 3D HA-carbon foams and a series of pristine graphene-derived foams, both plotted over the final (maximum) heat treatment temperatures. In both types of materials, the thermal conductivity increases monotonically with the final HTT. However, the presently invented process enables the cost-effective and environmentally benign production of HA-carbon foams that outperform pristine graphene foams. This is another unexpected result. [0143] 5) FIG.4(B) shows the thermal conductivity values of the presently invented hybrid foam and hydrothermally reduced GO graphene foam. Electrical conductivity values of 3D HA-carbon foam and the hydrothermally reduced GO graphene foam are shown in FIG.6. These data further support the notion that, given the same amount of solid material, the presently invented HA-carbon foam is intrinsically most conducting, reflecting the significance of continuity in electron and phonon transport paths. The carbon phase bridges the gaps or interruptions between HA sheets.
[0144] The internal structures (crystal structure and orientation) of several series of HA-carbon foam materials were investigated using X-ray diffraction. The X-ray diffraction curve of natural graphite typically exhibits a peak at approximately 2.theta.=26.degree., corresponds to an inter-graphene spacing (d.sub.002) of approximately 0.3345 nm. The RHA walls of the hybrid foam materials exhibit a d.sub.002 spacing typically from 0.3345 nm to 0.40 nm, but more typically up to 0.34 nm.
[0145] With a heat treatment temperature of 2,750.degree. C. for the foam structure under compression for one hour, the d.sub.002 spacing is decreased to approximately to 0.3354 nm, identical to that of a graphite single crystal. In addition, a second diffraction peak with a high intensity appears at 2.theta.=55.degree. corresponding to X-ray diffraction from (004) plane. The (004) peak intensity relative to the (002) intensity on the same diffraction curve, or the I(004)/I(002) ratio, is a good indication of the degree of crystal perfection and preferred orientation of graphene-like planes. The (004) peak is either non-existing or relatively weak, with the I(004)/I(002) ratio <0.1, for all graphitic materials heat treated at a temperature lower than 2,800.degree. C. The I(004)/I(002) ratio for the graphitic materials heat treated at 3,000-3,250.degree. C. (e.g., highly oriented pyrolytic graphite, HOPG) is in the range of 0.2-0.5. In contrast, a graphene foam prepared with a final HTT of 2,750.degree. C. for one hour exhibits a I(004)/I(002) ratio of 0.78 and a Mosaic spread value of 0.21, indicating the pore walls being a practically perfect graphite single crystal with a good degree of preferred orientation (if prepared under a compression force).
[0146] The "mosaic spread" value is obtained from the full width at half maximum of the (002) reflection in an X-ray diffraction intensity curve. This index for the degree of ordering characterizes the graphite or graphene crystal size (or grain size), amounts of grain boundaries and other defects, and the degree of preferred grain orientation. A nearly perfect single crystal of graphite is characterized by having a mosaic spread value of 0.2-0.4. Some of our graphene foams have a mosaic spread value in this range of 0.3-0.6 when produced using a final heat treatment temperature no less than 2,500.degree. C.
[0147] The following are a summary of some of the more significant results: [0148] 1) The presently invented HA-carbon hybrid foam materials typically exhibit significantly higher structural integrity (e.g. compression strength, elasticity, and resiliency) and higher thermal and electrical conductivities as compared to their graphene counterparts produced by the conventional, prior art methods. [0149] 2) It is of significance to point out that all the prior art processes for producing graphite foams or graphene foams appear to provide only macro-porous foams having a physical density in the range of approximately 0.2-0.6 g/cm.sup.3, with pore sizes being typically too large (e.g. from 20 to 300 .mu.m) for most of the intended applications. In contrast, the instant invention provides processes that generate HA-carbon foams having a density that can be as low as 0.001 g/cm.sup.3 and as high as 1.7 g/cm.sup.3. The pore sizes can be varied from microscopic (<2 nm), through meso-scaled (2-50 nm), and up to macro-scaled (e.g. from 1 to 500 .mu.m). This level of flexibility and versatility in designing various types of HA-carbon foams is unprecedented and un-matched by any prior art process. [0150] 3) The presently invented method also allows for convenient and flexible control over the chemical composition (e.g. F, O, and N contents, etc.) of foams, responsive to various application needs (e.g. oil recovery from oil-contaminated water, separation of an organic solvent from water or other solvents, heat dissipation, etc.). In conclusion, we have successfully developed an absolutely new, novel, unexpected, and patently distinct class of highly conducting humic acid-carbon hybrid foam materials, devices, and related processes of production. The chemical composition (% of oxygen, fluorine, and other non-carbon elements), structure (crystal perfection, grain size, defect population, etc.), crystal orientation, morphology, process of production, and properties of this new class of foam materials are fundamentally different and patently distinct from meso-phase pitch-derived graphite foam, CVD graphene-derived foam, and graphene foams from hydrothermal reduction of GO.
An autonomous vehicle includes an autonomous-driving system having at least one autonomous vehicle component disposed at a roof region of the autonomous vehicle. The autonomous vehicle further includes a thermal management system adapted to transmit a coolant in proximity to the autonomous vehicle component. The autonomous vehicle further includes a fluid management system having a catch basin secured to the roof region below the autonomous vehicle component. The fluid management system further includes a drain tube secured to the catch basin to receive coolant collected in the catch basin.
1. An autonomous vehicle comprising: an autonomous-driving system having at least one autonomous vehicle component disposed at a roof region of the autonomous vehicle; a thermal management system adapted to transmit a coolant in proximity to the autonomous vehicle component; and a fluid management system having a catch basin secured to the roof region below the autonomous vehicle component, and a drain tube secured to the catch basin to receive coolant collected in the catch basin.
2. The autonomous vehicle of claim 1, wherein the at least one autonomous vehicle component of the autonomous-driving system is an autonomous vehicle sensor.
3. The autonomous vehicle of claim 1, wherein the at least one autonomous vehicle component of the autonomous-driving system is an electrical component associated with an autonomous vehicle sensor.
4. The autonomous vehicle of claim 1, wherein the thermal management system includes at least one of a heat sink and a cooling plate disposed in contact with the autonomous vehicle component.
5. The autonomous vehicle of claim 4, wherein the thermal management system includes at least one closed-loop liquid cooling system disposed in contact with the at least one heat sink and cooling plate.
6. The autonomous vehicle of claim 1, wherein the catch basin defines a cavity adapted to receive the at least one autonomous vehicle component.
7. The autonomous vehicle of claim 1, wherein the drain tube is secured to the catch basin adjacent a catch basin drain opening, and wherein the drain tube extends from the roof region to a lower region of the autonomous vehicle.
8. The autonomous vehicle of claim 1, further comprising: at least one sensor adapted to sense a coolant property within the thermal management system; and a controller in communication with the at least one sensor and configured to communicate an indication of a fluid leakage to a user at a user interface.
9. A fluid management system for an autonomous vehicle, comprising: a catch basin adapted to be secured to a roof region of the vehicle in proximity to at least one autonomous vehicle component; and at least one drain tube secured to the catch basin adjacent a catch basin drain opening to receive coolant collected in the catch basin, the at least one drain tube extending from the roof region to a lower region of the vehicle.
10. The fluid management system of claim 9, wherein the catch basin defines a cavity adapted to receive the at least one autonomous vehicle component.
11. The fluid management system of claim 9, wherein the at least one drain tube extends through a pillar of the vehicle from the roof region of the vehicle to the lower region of the vehicle, and wherein the at least one drain tube is adapted to direct coolant from the catch basin through the pillar of the vehicle.
12. The fluid management system of claim 9, wherein the at least one drain tube includes a drainage outlet to permit fluid flow to an exterior of the vehicle.
13. The fluid management system of claim 9, wherein the at least one drain tube is connected to a retention basin disposed in the lower region of the vehicle.
14. The fluid management system of claim 9, wherein the at least one drain tube is a plurality of drain tubes, and wherein the plurality of drain tubes is connected to a retention basin disposed in the lower region of the vehicle.
15. A fluid control system for an autonomous vehicle, comprising: a closed-loop liquid cooling system adapted to transmit a coolant through a catch basin disposed at a roof region of the autonomous vehicle; at least one sensor adapted to sense a coolant property of the coolant within the closed-loop liquid cooling system; and a controller in communication with the at least one sensor and configured to communicate an indication of a fluid leakage to a user.
16. The fluid control system of claim 15, wherein the at least one sensor is disposed within a fluid conduit of the closed-loop liquid cooling system.
17. The fluid control system of claim 15, wherein the at least one sensor is disposed within the catch basin.
18. The fluid control system of claim 15, wherein the coolant property is a coolant pressure, and wherein the controller is adapted to communicate the indication of the fluid leakage in response to the sensor detecting a change in the coolant pressure within the closed-loop liquid cooling system.
19. The fluid control system of claim 15, wherein the controller is adapted to communicate the indication of the fluid leakage to the user at a user interface disposed within a cabin of the autonomous vehicle.
20. The fluid control system of claim 15, further comprising at least one drain tube secured to the catch basin adjacent a catch basin drain opening to receive coolant collected in the catch basin, the at least one drain tube extending from the roof region to a lower region of the autonomous vehicle.
[0001] This disclosure relates to fluid management for autonomous vehicle sensors, and more specifically, to a fluid management system for roof-mounted autonomous vehicle sensors.
[0002] A vehicle such as an automobile may be configured for autonomous driving operations. For example, the vehicle may include a central control unit or the like (e.g., a computing device having a processor and a memory) that receives data from various vehicle data collection devices such as sensors. The central control unit may also receive data such as navigation information from external data sources. The central control unit may provide instructions to various vehicle components such as actuators and the like that control steering, braking, acceleration, etc., to control vehicle operations without action, or with reduced action, by a human operator.
[0003] An autonomous vehicle includes an autonomous-driving system having at least one autonomous vehicle component disposed at a roof region of the autonomous vehicle. The autonomous vehicle further includes a thermal management system adapted to transmit a coolant in proximity to the autonomous vehicle component. The autonomous vehicle further includes a fluid management system having a catch basin secured to the roof region below the autonomous vehicle component. The fluid management system further includes a drain tube secured to the catch basin to receive coolant collected in the catch basin.
[0004] A fluid management system for an autonomous vehicle includes a catch basin adapted to be secured to a roof region of the vehicle in proximity to at least one autonomous vehicle component. The fluid management system further includes at least one drain tube secured to the catch basin adjacent a catch basin drain opening to receive coolant collected in the catch basin. The at least one drain tube extends from the roof region to a lower region of the vehicle.
[0005] A fluid control system for an autonomous vehicle includes a closed-loop liquid cooling system adapted to transmit a coolant through a catch basin disposed at a roof region of the autonomous vehicle. The fluid control system further includes at least one sensor adapted to sense a coolant property of the coolant within the closed-loop liquid cooling system. The fluid control system further includes a controller in communication with the at least one sensor and configured to communicate an indication of a fluid leakage to a user.
[0009] Referring now to FIG. 1, a vehicle 10 includes a roof panel 12 supported by pillars 14. The vehicle 10 may include an autonomous-driving system 16 having autonomous-driving components that provide semi-autonomous or autonomous driving features to the vehicle 10. These autonomous-driving components may connect to a vehicle network, and may send and receive information with the existing features of the vehicle. The autonomous-driving system 16 may include an electrical architecture and control system for automated driving functions. The autonomous-driving system 16 may receive input from various sensors, and may utilize driving algorithms to command braking, steering, acceleration, and other functions of the vehicle.
[0010] Referring to FIG. 2, the autonomous-driving system 16 may include a support structure 20 defining a cartridge 22 and a tray 24. The support structure 20 is adapted to support one or more autonomous vehicle components. For example, one or more autonomous vehicle sensors 26 may be disposed in and supported by the cartridge 22. The autonomous vehicle sensors 26 may be any sensor that may be mounted to the roof region of the vehicle 10 to provide semi-autonomous or autonomous driving features. Electrical components 28 required for the operation of the autonomous vehicle sensors 26 may be disposed in and supported on the tray 24. The electrical components 28 may include any component required for operation of the sensors 26, including but not limited to controller, cooling systems, or cabling.
[0011] The cartridge 22 may be composed of a carbon fiber composite material. Alternatively, the cartridge 22 may be a lightweight aluminum or any other lightweight panel to thereby allow the support structure 20 to support the plurality of sensors 26. The tray 24 may also be composed of a lightweight aluminum, or any other lightweight material, which provides support for the electrical components 28 on the tray 24. The areas defined by the cartridge 22 and the tray 24 may be optimized based on the relative sizes of the sensors 26 and the components 28, respectively. This allows the electrical components 28 for the sensors 26 to be disposed relatively close for optimal sensing.
[0012] In many implementations, autonomous vehicle sensors 26 and the electrical components 28 generate heat during operation. Furthermore, as the sensors 26 and the electrical components 28 are disposed at the roof 12 of the vehicle 10, the sensors 26 and electrical components 28 may further be heated by energy from the Sun. For example, on a 75.degree. F. (24.degree. C.) day, typical temperatures may be approximately 108.degree. F. (42.degree. C.).
[0013] As such, the vehicle 10 may be provided with a thermal management or cooling system 30 to assist in maintaining proper operating temperatures for components of the autonomous-driving system 16. The thermal management system 30, shown schematically in FIG. 1, may take various forms such as forced air or liquid cooling systems. The thermal management system 30 may include heat sinks or cooling plates mounted to, or in contact with, the sensors 26 and/or the electrical components 28. For example, the support structure 20 may act as a heat sink or cooling plate to receive heat from the electrical components 28. In another example, heat sinks and/or cooling plates may be mounted to, or in contact with, the support structure 20. In this way, heat generated by the sensors 26 and electrical components 28 may be transferred to the heat sinks and cooling plates.
[0014] In a preferred approach, the thermal management system 30 includes a closed-loop liquid cooling system. In this approach, a coolant is cycled (e.g., using a pump) through a fluid channel defining a coolant loop. The coolant may be, for example, a mixture of approximately 50% ethylene glycol and approximately 50% water. In some approaches, a corrosion inhibitor may be added to the mixture. Other coolants and coolant compositions are expressly contemplated.
[0015] At the roof 12 of the vehicle 10, the coolant loop runs proximate the sensors 26 and/or the electrical components 28 of the autonomous-driving system 16. In one approach, the coolant loop runs adjacent to the heat sinks or cooling plates mounted to, or in contact with, the sensors 26 and/or the electrical components 28. In another approach, the coolant loop runs adjacent to the support structure 20, to which the heat sinks or cooling plates may be mounted to or in contact with.
[0016] As the liquid coolant passes the heat sinks or cooling plates associated with the sensors 26 or electrical components 28, heat is transferred from the heat sinks or cooling plates to the coolant. In some applications, the coolant used to cool the sensors 26 and electrical components 28 may reach approximately 158.degree. F. (70.degree. C.). Upon transfer of heat to from the sensors 26 and electrical components 28, the coolant travels through the coolant loop to a heat exchanger, where heat is rejected to the ambient air.
[0017] To manage coolant flowing through the thermal management system 30, the autonomous vehicle 10 may be provided with a fluid management system 40. The fluid management system 40 includes a catch basin 42 installed at the roof 12 of the vehicle. The catch basin 42 may be disposed, for example, between a headliner of the vehicle 10 and an external roof structure of the vehicle 10.
[0018] In a preferred approach, the catch basin 42 is secured to the roof region 12 below one or more components of the autonomous-driving system 16. In this approach, the support structure 20 of the autonomous-driving system 16 may be disposed within the catch basin 42. For example, the sensors 26 or electrical components 28 of the support structure 20 may be received within a cavity of the catch basin 42. The catch basin 42 may have a continuous bottom on which the support structure 20 is installed or otherwise retained.
[0019] In another approach, the catch basin 42 defines a ring adapted to surround the sensors 26 and/or the electrical components 28. For example, the catch basin 42 may form a ring about the periphery of the support structure 20.
[0020] In either approach, the catch basin 42 is adapted to collect coolant or other fluid that may leak from the sensors 26 or electrical components 28 of the support structure 20. The catch basin 42 may be, for example, a shallow tray adapted to cover or attach to the underside of the areas serviced by the thermal management system 30. In the approach shown, the catch basin 42 is a generally square catch basin having upright walls surrounding the support structure 20 of the autonomous-driving system 16. The catch basin 42 may take any form suitable to captures leakage from the thermal management system 30, thereby reducing the likelihood of the heated coolant from entering the cabin of the vehicle. The catch basin 42 may be formed, for example, of a metal or plastic material suitable for retaining coolant, including heated coolant (e.g., coolant heated to approximately 158.degree. F. (70.degree. C.)).
[0021] The fluid management system 40 may further include one or more drain tubes 44 extending from the catch basin 42. The drain tubes 44 may be any flexible tube for allowing a fluid to flow there through. In a preferred approach, the drain tubes 44 are formed of aluminum, a synthetic rubber, or any other material suitable for transferring heated liquid coolant.
[0022] Each drain tube 44 may be secured to the catch basin 42 at drain openings 46 (shown in FIG. 2) disposed through a wall of the catch basin 42. The catch basin drain openings 46 may take any suitable shape and extend through the entire thickness of the catch basin 42 to permit fluid communication from inside the catch basin 42 to outside the catch basin 42. Furthermore, the drain openings 46 are preferably located at lower regions of the catch basin 42 so as to receive fluid collected in the catch basin 42. In a preferred approach, the catch basin 42 includes at least four drain openings 46 disposed at the corners of the catch basin 42. However, the catch basin 42 may be provided with one, two, three, or five or more drain openings 46. Furthermore, the drain openings 46 may be disposed at any suitable location of the catch basin 42.
[0023] The drain tubes 44 are configured to route a fluid collected in the catch basin 42 to a lower region of the vehicle 10. In the illustrated example of FIG. 1, the drain tubes 44 are disposed within the pillars 14 of the vehicle 10. For example, the drain tubes 44 may travel through the forward and rear pillars in the space empty space between the inner and outer body structure. From the pillars 14, the drain tubes 44 may travel down into the lower region of the body structure of the vehicle 10. As used herein, the lower region of the body structure of the vehicle refers to a region of the vehicle 10 below the lower ends of the pillars 14. For example, the lower region may be a region at or below the underbody of the vehicle 10. In this way, fluid traveling from the catch basin 42 through the drain tubes 44 may exit out underneath the vehicle 10.
[0024] Each drain tube 44 may be provided with a drainage outlet 48. In one approach, the drainage outlet permits fluid flow to the exterior of the vehicle 10. To regulate discharge, the drainage outlet may be provided with drainage valves. In this way, an end user or service technician may drain each drain tube 44 in a controlled process to dispose of leaked coolant.
[0025] In another approach, each drain tube is connected to an individual retention basin having an associated tube valve. In still another approach, each drain tube may be connected to a single collective retention basin. In still another approach, a forward set of drain tubes may be connected to a forward retention basin, and a rear set of drain tubes may be connected to a rear retention basin. Retention basins may be, for example, plastic tanks. In a preferred approach, a retention basin includes an overflow opening at the top such that, in the event of a tank overflow, retained fluid may drain out onto the ground rather than backing up into the drain tubes, and potentially backing up into the catch basin. In these approaches, the fluid routed by the drain tubes may be retained in one or more retention basins until the fluid may be safely disposed of. For example, the one or more retention basins may be provided with a drain plug disposed at the bottom (or other suitable location) of each basin. An end user or service technician may then drain the one or more retention basins in a controlled process to dispose of leaked coolant.
[0026] In a preferred approach, the fluid management system 40 may include one or more sensors 50. For example, as shown schematically in FIG. 1, one or more sensors 50 may be disposed within the thermal management system 30 (e.g., within the closed loop liquid cooling system). The sensors 50 may be any sensor capable of sensing a coolant property within closed loop liquid cooling system. In one approach, the sensors 50 are disposed within fluid conduit of the thermal management system 30 to detect one or more properties of fluid flow through the thermal management system 30. For example, the sensors 50 may be configured to detect a pressure drop in the coolant. The sensors 50 may further be configured to detect a temperature increase or sustained elevated temperature of the sensors 26 or electrical components 28 connected to the support structure 20. Detected coolant pressure drops or temperature increases may be indicative of one or more leaks in the thermal management system 30.
[0027] In another approach, one or more sensors may be located in the catch basin 42. In still another approach, one or more sensors may be located within one or more of the retention basins. Sensors within the catch basin 42 or the retention basins may be adapted to detect the presence of fluid, thereby indicating a fluid leak in the thermal management system 30. Such sensors may be pressure sensors, corrosion test structures, humidity sensors, or other sensors capable of sensing a leak in the thermal management system 30.
[0028] The autonomous vehicle 10 may be provided with a fluid control system. For example, a controller 52, shown schematically in FIG. 1, may be in communication with the sensors 50. The controller 52 may be adapted to continuously monitor the sensors 50 for indication of a leakage in the thermal management system 30.
[0029] In response to the sensors 50 detecting a leakage in the thermal management system 30, the controller 52 may be configured to discontinue service of the autonomous vehicle 10 until further user action is taken. For example, the controller 52 may be configured command the autonomous vehicle 10 to autonomously park in a safe manner and to shut down so as to prevent damage to the sensors 26 or electrical components 28.
[0030] The autonomous vehicle 10 may further be provided with a user interface 54 disposed, for example, in a cabin of the autonomous vehicle 10. The controller 52 may be configured to command the user interface 54 may provide a user an indication of a fluid leak detected in the thermal management system 30. The user interface 54 may include a visual or audio indicator. For example, the user interface 54 may be a graphical display. The user interface 54 may instead, or also, be an audible alarm. The controller 52 may be adapted to communicate the indication of the fluid leakage in response to one or more sensors 50 detecting a change in coolant pressure within the closed-loop liquid cooling system.
[0031] In this way, an autonomous vehicle with a thermal management system may be provided with a fluid management system for collecting leaked fluid, such as heated coolant fluid, from the roof of the vehicle and safely diverts the leaked fluid. The fluid management system described herein may reduce the risk of leaked fluid dripping into the passenger cabin of the vehicle.
[0032] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
The invention relates to a method for providing object-related service in a telecommunications network, specifically in an intelligent network. In accordance with the method, service programs (SLP) are stored in a network element and service is provided by starting in the network element a service program in the selection of which at least the service key contained in the service request is used as a criterion. In order for it to be possible to implement services tailored to subscribers of objects more easily than heretofore, (a) a set of features is first selected by means of the service key, and thereafter object-specifically a subset of said set, and (b) the object-specific service is provided by executing in succession at least some of the features belonging to said object-specific subset.
1. A method for providing object-specific service in a telecommunications network, specifically in an intelligent network, the method comprising the steps of: storing service programs in a network element of the network; providing service by starting in the network element a service program in the selection of which at least a service key contained in the service request is used as a criterion, an individual service comprising a set of service features; maintaining object-specific identifiers of the service features relating to an individual object; selecting a set of service features by means of the service key, and thereafter object-specific a subset of said set by means of said identifiers; and providing the object-specific service by executing in succession at least some of the service features belonging to said object-specific subset.
2. A method as claimed in claim 1, wherein the network element maintains a first data table storing the set of allowable service feature keys for each service key in use and at least one second data table storing object-related rows in each of which the keys of the service features relating to the object are stored, said set being selected on the basis of the service key from the first data table and said subject by selecting from the object-related row of the second data table at least some of the service features belonging to said set.
3. A method as claimed in claim 2, wherein information on whether the service feature is active or passive is stored for each feature relating to an object, all active features belonging to said set being selected for said subset.
4. A method as claimed in claim 2, wherein information on a relative order of execution of the service features is also stored in the object-related row.
5. A method as claimed in claim 4, wherein at least one of said second data tables is provided for each object class in use.
6. A method as claimed in claim 1, wherein the selection process performing the selection of said set and subset is first selected from among several possible processes on a basis of the service key.
7. A method as claimed in claim 5, wherein a dedicated selection process is constructed in the network element for each object class in use, said selection process being chosen according to the object class to which the service is being provided.
8. A method as claimed in claim 1, wherein at least calling subscribers and called subscribers are used as object classes.
9. A method as claimed in claim 2, wherein at least some of the service programs are implemented in such a way that the service program has at least two parallel modules executing different service features, for each of which a dedicated service key is provided.
10. A method as claimed in claim 9, wherein from an end of each parallel module, the execution of the service is branched off, on the basis of a key of the service feature next in turn, to the beginning of the module corresponding to said service feature.
11. A telecommunications network in which users can place call attempts, the telecommunications network comprising: at least one network element which is adapted to send service requests containing a service key and in which objects belonging to different classes can be identified; and at least one network element adapted to receive service requests and storing service programs, wherein the network element receiving service requests comprises first selection means for selecting a set of service features on a basis of the service key value contained in the service request received, object-specific stored data on the service features relating to an individual object, and second selection means for selecting from the object-related data at least some of the service features belonging to said set.
The access of the end user,(subscriber) to the network is handled by the CCAF (Call Control Agent Function). The access to the IN services is implemented by making additions to existing digital exchanges. This is done by using the basic call state model BCSM which describes the existing functionality used to process a call between two users. The BCSM is a high level state automaton description of the call control functions CCF required for establishing and maintaining a connection route between users. Functionality is added to this state model by using the service switching function SSF (cf. the partial overlap of the entities CCF and SSF in FIG. 1) so that it is possible to decide when it is necessary to call the services of the intelligent network (the IN services). After these IN services have been called, the service control function SCF that contains the service logic for the intelligent network handles the service-related processing (of the call attempt). The service switching function SSF thereby connects the call control function CCF to the service control function SCF and allows the service control function SCF to control the call control function CCF. For example, SCF can request that the SSF/CCF perform specific call or connection functions, for example charging or routing operations. The SCF can also send requests to the service data function SDF which handles the access to the service-related data and network data of the intelligent network. The SCF can thus for example request the SDF to retrieve specific service-related data or update this data.
The physical level architecture of the intelligent network describes how the functional entities described above are located in the physical entities of the network. The physical architecture of the intelligent network is illustrated in FIG. 2, where the physical entities are described as rectangles or circles and functional entities as ovals. The signalling connections are described by dashed lines and the actual transport which is for example speech, by continuous lines. The optional functional entities are denoted with dashed line.
The signalling network shown in the Figure is a network according to SS7 (Signalling System Number 7 is a well-known signalling system described in the CCITT (nowadays ITU-T) blue book Specifications of Signalling System No. 7, Melbourne 1988).
It should be possible to provide IN-based services to subscribers in fixed or mobile networks in a way enabling provision of individual service tailored to personal needs as far as possible. As stated previously, provisioning of a service is in practice initiated in such a way that the SSF sends to the SCF a standard IN service request. The service request can be sent at certain stages of the call setup. The international standards, however, specify only one identifier for the service request sent by the SSF wherewith the desired service logic can be selected in the SCP. This identifier is called the service key.
The generally known technique for providing tailored services is such that the final service logic program (SLP) is selected in the SCP by means of the service key value, in which case more than one values can point to the same service logic program or there may be a dedicated service logic program for each service key value.
This solution means that the service key values used in the SSP exchange must be used in the SCP exchange to select the service logic programs, even though the key is originally intended merely for identifying the service. The drawback with this solution is that the implementation of the network will be rendered far more difficult with the increase in services and features contained in them, as one strives at providing subscribers (or other objects) with services better tailored than heretofore to specific personal needs. In the future, an individual IN service may comprise for example 10 different service features, in which situation each subscriber can select a service suited to him, consisting of a desired subset of said features or a combination of all features. A subservice, for which the English term service feature (SF) is employed in the international standards, will be termed a feature in this context.
Hence, the problem must be solved how it is possible to indicate using the standard service key mechanism the specific subset of service features relating to an individual object, e.g. an individual subscriber, simultaneously keeping the network implementation and maintenance as simple as possible.
This object is achieved with the solution in accordance with the invention, which is defined in the independent claims.
The idea of the invention is to define for an individual service key value the set of features that are allowable, and first to select said set by means of the service key arriving in each case and thereafter to search object-specifically which features relating to said object and indicated as active belong to said set. Thereafter the service can be provided by executing the features found, or at least some of them.
By means of solution in accordance with the invention, a system can conveniently be achieved in which the set of features to be executed changes according to which service key value and which object are concemed. This affords more flexibility in producing the services, and enlarging the service selection available to subscribers will be simplified.
The solution in accordance with the invention also affords an advantageous solution in view of network management, since the SSP exchange can utilize a small number of different values as service keys on account of the fact that the SSP exchange only has to identify those subscribers who have a version of a given IN service or of a service belonging to a group of related IN services. In that situation, on the basis of said service key a process is selected in the SCP exchange that is capable of finding, by examining a subscriber-specific information element, what kind of service version said subscriber has.
When the call control of the SSP exchange detects that a subscriber is concerned who needs IN services, transfer of the control to the IN is triggered and processing of the call attempt is "frozen". The SSP exchange then sends to the SCP an Initial_DP message, which is a standard message between the SSF and SCP, generated by the SSF upon detecting at any detection point of the call state model that a service request is necessary (a detection point is a point in the call state model at which the control can be transferred to the IN). Initial_DP is thus the message that starts the dialog between the SSP and the SCP relating to the provision of each service. The information elements included in the message by the SSP exchange comprise at least the calling and called number and the service key.
When an initiation request for a service dialog--which arrives as a TC_BEGIN primitive (containing an Initial_DP message)--is received on a network element, a new instance of the receiving program SRP is created that will search the correct distributor program block, create an instance thereof for the use of said service request, and transmit a TCAP message to said instance. Thereafter the instance of the receiving program block is deleted. The distributor program instance receives all TCAP messages subsequently arriving from SSP. The search for the correct distributor program takes place in such a way that the receiving program block SRP reads from the header of the TC_BEGIN message either the identifier of the sending SSP network element (SPC, Signalling Point Code, or GT, Global Title) and additionally the identifier of the subsystem (SSN, SubSystem Number), or alternatively the relevant application context identifier AC, and searches on the basis thereof from the data table SRP_DT of the SRP level the name of the distributor program, MDP_NAME, corresponding to the INAP message set in question.
Since service logic needs are different for different object types, it is advantageous to implement the SCP network element in such a way that it has separate main program blocks for the logically distinct main object classes contained in the SSP exchanges. Said classes may include calling subscriber class, called subscriber class, destinations (beginning of dialled number), sub-destinations (the entire dialled number), routes, circuit groups, etc. Furthermore, the subscribers may be in different classes according to which network they belong to (for example a fixed network or mobile network). Objects in this context denote such network-related entities to which information can be attached in the network element--e.g. in the case of an intelligent network in an SSP network element--indicating, for an individual call attempt, whether a service request is to be sent to the network element offering services (which in the case of an intelligent network is an SCP network element).
As stated previously, each distributor program block utilizes the service key parameter that arrived in the service request message to define the receiving main program block. This means that for service requests relating to a given main object class (e.g. calling subscribers), the SSP exchange has to set a service key value that is different from the service key value of objects belonging to another class (e.g. called subscribers) (even though service of the same type is concemed). A wide variety of service key values may correspond to a given main program block, but the service key value sets relating to two different main programs may not overlap.
Each main object class has a dedicated data table FMPi_DT (i=1,2, . . . n). These data tables will be termed main tables in the following. Thus, the SCP network element has a dedicated main table for each main program block. Each main table has one data row for each object belonging to said class. For example, the data table (FMP1_DT) used by the main program block FMP1 relating to calling subscribers has one data row for each calling subscriber Ai (i=1, 2 . . . ), the data table (FMP2_DT) used by the main program FMP2 relating to called subscribers has one data row for each called subscriber Bi (i=1, 2 . . . ), the data table used by the main program relating to subdestination objects has one data row for each subdestination in use, the data table used by the main program relating to destination objects has one data row for each destination in use, etc.
In each row of the main tables, information is stored in the manner shown in FIG. 4, defining what kind of feature set said object has activated. An object identifier OI is stored at the beginning of each row R as a search key. The main program block searches the correct row from its data table by means of the value of the object identifier contained in the INAP message. The row contains successive subrecords SR, one for each feature. At the beginning of each subrecord, there is a field FK containing a feature key Fki (i=1,2 . . . ), indicating which feature is concemed. Thereafter the subrecord may have for example a status field ST, containing information on whether said feature is active or passive, and a priority field PR, containing a priority number. These priority numbers of subrecords indicate the relative order of execution of the features. Each subrecord further has at least field SLP, containing the identifier of the service logic program that executes said feature. The service logic programs form the lowest hierarchy level of the network element.
In practice, one feature implemented by a service logic program may be for example playing of an announcement to the subscriber ("play an announcement") or an operation by which the calling subscriber is requested to dial additional numbers ("prompt and collect user information"), or a connect operation (a CONNECT message is sent to the SSP exchange, by which the SSP exchange is requested to connect the call to a given address).
The FMP instance thus sends an Initial_DP message to the service program which has the highest priority and whose identifier the main program block read from the relevant subrecord of the object-related row. First, however, a separate request message REQREC is sent to said SLP instance, since the Initial_DP message must be sent in its standard format (ASN.1 format) in which its information content is not sufficient. The service logic program thus needs also other data in addition to that contained in the INAPmessage, for example the value of the feature key, which it receives in the request message.
FIG. 6 illustrates one possible structure of an acknowledgement message INFOREC sent by an SLP instance. The first field SLP_ID2 indicates the identifier of the sending SLP instance. The next field WAIT contains for example information on whether a response is awaited from the network before the service can be continued. The field FLAG_D contains a Boolean variable indicating whether the SLP instance terminates itself after sending of an acknowledgement message or not. The field LAST_REQ again contains the same information that the child has last received from the parent in said field (the grandparent thus also receives said information). The next field LAST_INFO again contains a Boolean variable indicating whether the SLP instance has completed the last feature of the request message it received. The next field Fk contains the key of the feature in which said message arrives as an acknowledgement. The field CC contains the termination code of the feature just completed. The field ECC can indicate slight errors for which a separate error message need not be sent. The field EndDlg contains information on in which way said SLP instance desires its grandparent to terminate said dialog. The dialog can have different ways of termination, for example depending on whether a message is desired to be sent to the network, or if a message is sent, what information elements are included in the TC_END primitive to be sent.
After receipt of the InitialDP message in the initial state block, the service proceeds to one of the feature modules FM. The start of a feature normally comprises a function block FB in which the information contained in the initiation message is processed.
FIG. 9 illustrates the functionality of the halt state block HSB. In addition to the above, what is essential is that this block can include functions that are inessential to the actual service logic (needed by the subscriber). Such functions include transmission and reception of data messages that are not network messages (INAP messages) but messages internal to the network element, wherewith for example the timeouts or acknowledgements performed within the network element are handled. The halt state block thus has one or more internal message transmission blocks IMT, wherefrom a message internal to the network element is transmitted and at least one delay state DS, in which a synchronous response (a specific INAP message) is awaited (which is hence called a synchronous halt state). Under the delay state there are additionally--as above--at least branches for processing (a) a timeout message indicating that one has awaited too long in the delay state, and (b) a termination message internal to the network element, wherewith the execution of the service is terminated for example on account of an error. If an internal timeout or termination message or for example an error message arriving from the network is received, the routine enters the end state block ESB directly. Thus, the branching variable used at the end of the halt state block is the type of the received message. (The figure shows the INAP messages of various types as one item.)
To find one or more features to be performed next, another data table FMP_DT2 (FIG. 4) common to a given set of main program blocks is used at the main program level. This data table indicates the mutual interaction of the features. The primary search keys in the data table are the feature key Fk and the termination code Tc. The table contains the possible features for each feature/termination code pair. In other words, the table always contains the set of features that is possible to perform next when the executed feature and its termination code are known. When the set of features that can succeed the feature just executed has been found in the table, the feature-having the highest priority in the object-related data row (or in data table FMP_DT1) is selected from among said features as the one to be executed next. When this feature has been executed, a termination code is again received in the acknowledgement message, and thus a new feature set is again found on the basis of the termination code and the feature key, and the feature to be executed next is selected from this set on the basis of the object-related data.
In the simplest case, the feature module (i.e., feature) comprises one function block, one messaging block and one stop state block (no halt state block). This is the situation for example if an initiation message arrives from the SSP exchange to the effect that the SCP network element need only send to the network a CONNECT type message (to which no synchronous response is awaited).
By means of the state blocks in accordance with the invention, service independent building blocks are formed for the reception of an initiation message (initial state block), reception of synchronous responses arriving from the network (halt state block), concatenation of features (stop state block), and for service termination operations that are the same irrespective of which service logic program is concerned (end state block). State blocks of the same type are similar in all service programs. Also the end state block terminating the service is called a state block, since in said block release messages must be sent to the network and a final response from the network (Calllnformation Report, a message that the system must be capable of receiving even after a release message has been sent to the network) must be awaited (in delay state). Termination operations are carried out in the end state block also in cases where a jump is made from the middle of the feature module directly to the end state block to terminate the service.
The above is a description of the implementation of services in a case where all features can be executed in immediate temporal succession. However, some services are of such a nature that this is not possible, but one must wait between two successive features before the execution of the service can be continued. The service may be such for example to calling subscribers who are credit customers, in which case the balance of the account must be checked in between during the call. During the service, one must possibly also await a specific event, for example the calling subscriber dialling more numbers. Even after all features have been executed, the SLP instance must possibly be kept alive because one must still await an asynchronous response from the network, for example information on the calling subscriber placing the receiver on hook.
It is advantageous to implement passing of such "idle time" in the service logic as a separate feature, in order that it can be constructed as a service independent building block. In accordance with a preferred embodiment of the invention, each service program has, in addition to the other feature modules, a special feature module for passing of such "idle time". This feature module is called the idle module.
Hence, a preferred additional embodiment of the invention includes special exception blocks enabling a leap to the end of the feature module and therefrom further to the start of the desired feature module, where the asynchronous response that has arrived is processed and from the end of which one can return, when necessary, to the start of the idle module. There is a dedicated exception block instance for each possible asynchronous response. The use of exception blocks has the advantage that thereby the code of the idle module IFM can be made identical in all service programs.
FIG. 11 illustrates the structure of an idle module IFM provided with exception blocks EB. From the halt state block HSB', in which all possible asynchronous responses can be received, the routine branches off after the message preprocessing block MB to a dedicated exception block instance EB according to the asynchronous response that has been received. As is shown in the figure for one exception block, in each exception block instance values are first given to parameters iERR and NextFk, and thereafter a jump is made directly to the start of the stop state block SSB located at the end of the feature module. The parameter iERR indicates whether the service logic has passed through the exception block and what kind of exceptional situation is concerned. The parameter NextFk again indicates the key of the service that is desired next.
If exception blocks of the kind described above are used, a test has been added to the stop state block SSB in which it is tested whether the stop state block is entered directly from an instance of an exception block and if so, what kind of exception is concerned. FIG. 12 illustrates such a stop state block which is otherwise similar to that shown in FIG. 10, but steps 98, 99 and 100 have been added to the start of the block, and steps 105a and 106 have been added after the reception of the request message. At the start of the block, it is first tested (step 98) whether the stop state block is entered from an exception block. This can be effected in such a way that the parameter iERR has otherwise the value zero, but in the exception state block it receives a value higher than zero. For example the value one can indicate that an asynchronous response has been received that requires processing in a dedicated feature module, and the value two can indicate that an asynchronous response (for example a termination message) has been received that requires termination of the service (jump to the end state block). Hence, it is tested in step 98 whether the value of parameter iERR is smaller than or equal to zero. If this is the case (that is, the stop state block has not been entered directly from the instance of the exception block), the execution of the feature proceeds in the manner described above. If the parameter has a value higher than zero, step 99 is proceeded to, in which it is tested whether the parameter has a value smaller than or equal to one (i.e. whether the value is exactly one). If the parameter has previously been given the value one, the routine proceeds to step 100, in which the value of the parameter NextFk is set in field NFk of the acknowledgement message and step 103 is proceeded to, in which an acknowledgement message is sent. If the parameter iERR has been given a value higher than one, the routine proceeds directly to the end state block ESB.
In a situation where all features have been executed, the main program block can also send, instead of a termination message, a request message comprising no feature key. In such a case, it is checked from the request message (step 105a) whether it contains feature keys. If there are no feature keys, it is checked whether there are still asynchronous responses to be received from the network (step 106). If this is the case, the routine proceeds to the idle module to wait. If there are no pending responses, the routine proceeds to the end state block.
The feature to be executed next need not necessarily be defined in the acknowledgement message; if for example the parameter iERR is given the value 2, the service logic proceeds directly to the end state block. Such values are used in situations in which the asynchronous response received in the halt state block HSB' is such that the execution of the service is to be terminated immediately.
Even though the invention has been described in the above with reference to the examples in accordance with the accompanying drawings, it is obvious that the invention is not to be so restricted, but it can be modified within the scope of the Inventive idea set forth above and in the appended claims. The set of features implementing the object-related service can also comprise all features indicated by the service key, even though it typically is a subset of the set of features indicated by the service key. The term subset is thus to be construed as including this alternative as well. The service programs can also be implemented with the conventional structure, even though the implementation presented above is preferable, since it will assist in simplifying the production of services and in adding flexibility of service implementation. The different main object classes can also be located in different network elements, even though they have been presented in the above as all being located in the same network element. Service programs can also be located in network elements of different types, for instance such that do not directly receive service requests.
Owner and founder Pauline Curtiss began with a background in fine art, using her creativity to design a variety of finishes and objects to beautify interior spaces. She has focused on creating hand printed custom designed patterns, color consultations, interior painting, faux finishing and unique murals specifically created for your home for over fifteen years. We have a staff of four women working on projects with the ability to execute large and small jobs locally and in other states. Pauline Curtiss received her degree in fine arts from the Rhode Island School of Design. Her interests in patterns begin primarily with fine art. The negative and positive sculptural shapes created by carving wood, stone, or by casting metal. The off-set overlays fashioned by printmaking. The striae of glazes which mimics texture of light and shadows.
Pauline's work has been featured in Elle Decor, New England Home Magazine, and has been on This Old House.
Much of her fine art is comissioned by companies, or individuals. see her painting website at www.paulinecurtiss.com
Every aspect of these visual elements are carefully selected to complement and transform your furnishings and architecture, adding a unique flair to your home or business. Our attention to detail is impeccable. All decorative painting is envisioned after thoughtful consideration of the elements in your house.
Trademark designs incorporate old world design influences with modern playful twists. These beautiful ornamentations are hand painted on walls, flooring, ceilings, fabric or furniture. All artistry reflects your specific taste, enhancing the beauty of your environment. Pauline also designs rugs, tile and millwork. Her company website for these products is www.seraserdesigns.com
Silver are dominant on this The Best Outdoor Wicker Furniture Brands Within Best Patio Furniture due to table below. Then purplish brown & almost blackcolor scheme is make it perfect. Combination beetween pinkish grey, greyish brown, reddish grey, dark olive, dark slate blue are wraping around the room.
Below is the table contains color information of The Best Outdoor Wicker Furniture Brands Within Best Patio Furniture.
Hello Internet! So first off, I should apologize for the lack of posts. The past few months I’ve been playing in a few musicals that took up most of my February and March. Now...
I always liked the colorful light effects in the pictures...So I came up with the idea of creating a portable led projector for photography and movie making.An infinite number of filters that we can make for such a lamp expand its possibilities in photography. Filters can be made of various lenses, ...By: AvocreativityContinue Reading »
I have a rather basic understanding of electronics, which is why I’m super proud of my DIY Ambilight setup in a basic wooden enclosure with the ability to turn the lights on and off as and when I please.For those who don't know what an Ambilight is; its a set of LED strips that are […]
I recently posted an Instructable upon my first experience of re-aligning the optics in an old pair of binoculars and although successful, it relied heavily on a subjective assessment of how the images could be brought into alignment by altering the optical path through the binocular’s objective len...By: OrganikmechanicContinue Reading »
This has been written by Autodesk Tinkercad as a resource to support the 'Hour of Code™'. The Hour of Code is a nationwide initiative by Computer Science Education Week [csedweek.org] and Code.org [code.org] to introduce millions of students to one hour of computer science and computer programming. ...By: Tinkercad for EducationContinue Reading »
Everyone has their own hobby; something they are good at and enjoy to do. Mine happens to be fishing. I've been fishing since I could walk. It first started as a few times a year with my grandpa and dad. Now, hardly a week goes by that I'm not out on the water wetting a […]
In a world where every other Star Wars character has their own variation of bike/skate helmets to choose from, I wanted to make one for one of my favorite Star Wars characters that doesn't have their own helmet yet - K2SO.Here's how I put it together: Materials The materials I used:Black skate he...By: OnceUponaWorkbenchContinue Reading […]
This application was ran on a co2, 120 watt, Trotec Speedy 400 Laser with a 2.5" lens. Depending on the wattage of your laser the material settings might be different than what is shown below. Cutting and Engraving on Trolase Thin Place you TroLase thin 0.5 mm adhesive material or whichever thin...By: masterURlaserContinue Reading »
Who has the time during the holiday season to create healthy and beautiful desserts that the whole family will LOVE? I know for sure that I barely have time to visit both sides of the family let alone spend four frustrating hours in the kitchen decorating cupcakes that only end up being made fun of […]
How to Design and Laser Cut a Steampunk Building and Country Cottage for Wargame Terrain November 19, 2018
In this instructable I show how to modify the same basic scale model and give it two different looks: steampunk and country cottage. These models are scaled for 28mm miniatures, such as Warhammer and Warmahordes. The design is done in Adobe Illustrator, the parts are cut on a laser cutter and it is ...By: greylightmayContinue […]
Thanksgiving is right around the corner and I can't believe that the holidays are already upon us! One of my favorite sides for Thanksgiving is this classic Green Bean Casserole. This recipe is so simple, delicious and comes together quite quickly. I have always loved taking this to my mom's house f...By: ModernFarmhouseKitchenContinue Reading »