bluuebunny/crossref_metadata_2025 huggingface dataset:
Alkylphenol Modified Phenolic-Latex Film and Effect of Humidity and Temperature on Tensile Property of Coating Fiberglass
Authors: Shen Ming Xia , Fang Wen Xue , Zhang Jun Shen , Chen Qing Min
Published: September 2009

Phenolic-latex film is used to coat on fiberglass surface to protect and supply fiberglass an intensive and adhesive coating for reinforcing fiber/rubber composite purpose. A series of p-alkylphenol was introduced to modify the hydrophobicity of resorcinol- formalin-latex (RFL) film surface and to prepare a p-alkylphenol-resorcinol-formalin-latex (ARFL) film, which alkyl carbon number was 1, 4, 9, 12, respectively. The surface characteristic of ARFL films was evaluated by Fourier transform spectra (FTIR) and contact angle and X-ray photoelectron spectroscopy (XPS) analysis. The surface micrograph of fiberglass pulled from H-sample was observed by scanning electron microscope (SEM). The best hydrophobicity was obtained on the nonylphenol-resorcinol- formalin-latex (NRFL) film. A better adhesion was gained for NRFL coated fiberglass comparing to RFL one. The effect of temperature and humidity on the tensile property of coated fiberglass was also discussed. The shelf life of NRFL-coated fiberglass was prolonged to six weeks under hot and humidity weather. The discussed coating may be popularized to other fiber surface to lower the effect of moisture.
Decomposition of Toluene at Optimal TiO2 Thin Film Photocatalytic Process Using the Taguchi Method
Authors: Lin Ching Hsing , Chang Yu Jie , Hwa Mei Yin , Hsieh Yung Hsu , Yeh Shi Hong , Chang Chen Yu
Published: September 2009

In this study, the Taguchi method was used to optimize the preparation of titanium dioxide thin film reactor through modified chemical vapor deposition (CVD) method and then conversion ratio of toluene was evaluated at the optimal condition. The results indicated that optimal condition for preparation of TiO2 thin film reactor was as followings: water bath temperature of 80°C, Ti (OC3H7)4 / H2O ratio of 4, carrier gas flow rate of 1000 mL min-1, catalytic oxidation temperature of 400°C, oxidation time of 8 hrs, calcination temperature of 450°C, spraying speed of 30 rpm and furnace linear motion geared motor speed of 75 cm min-1. The conversion ratio of 56.56 ppmv toluene could be achieved up to 99.8% with the irradiation intensity of 3.76μW cm-2 at the flow rate of 300 mL min-1 after 120 minutes.
Photocathode Protection Properties of TiO2/V2O5 Coating
Authors: Zhou Min Jie , Zhong Li
Published: September 2009

Nano-sized TiO2/V2O5 bilayer coatings were prepared on type304 stainless steel substrate by sol-gel method and were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD). The performance of photocathode protection of the coating was investigated by the electrochemical method. SEM results indicate that the coating surface is continuous, uniform and dense, XRD spectra show that the coating is of anatase TiO2 and V2O5. The experimental results demonstrate that type 304 stainless steel with the bilayer coating can maintain cathode protection for 6h in the dark after irradiation by UV illumination for 1 h.
Effect of Thicknesses on the Optical and Electrical Properties of Ag Films on PET Substrates
Authors: Lv Jing , Zhang Sheng Ni
Published: September 2009

A series of Ag films with different thicknesses were prepared on polyethylene terephthalate (PET) substrates under identical conditions by thermal evaporation. The effect of the thickness on the optical and electrical properties of the films was studied. The morphology of the samples was investigated by atomic force microscopy (AFM). The optical and electrical properties were measured by spectrophotometer and four-point probe method, respectively. The experimental results show that the reflectance increases, while transmittance and resistivity decrease with the increase of the thickness. There exists a critical thickness of the film and it is 75 nm in this experiment. The optical and electrical properties of Ag films on PET substrates with thickness larger than critical thickness, are close to those of the conventional bulk silver. The resistivity of the 150-nm film is 3.0±0.2 μΩ•cm, which is lower than that of the 250-nm Ag film grown on BK-7 glass substrates.
Structures and Solid-Liquid Phase Transition of High-Density Hydrogen Confined in Single-Walled Carbon Nanotubes
Authors: Xia Yue Yuan , Zhao Ming Wen , Liu Xiang Dong , Ji Yan Ju
Published: September 2009

Hydrogen with ultrahigh density confined in single-walled carbon nanotubes (SWCNTs) was investigated using density functional theory (DFT) and first principles molecular dynamics simulations (MDSs). Hydrogen atoms injected in to the cages of the SWCNTs via atomic collisions gradually form solid H2 molecular lattice with a characteristic of spiral multi-strands structure. The concentration of H2 confined in the SWCNTs can be as high as ~ 1.77×1023H2 /cm3, and the pressure between the H2 lattice and the wall of the SWCNT can be as high as ~ 77 GPa. When the system was heated to temperature higher than 700K, a solid-liquid phase transition was observed. When temperature rose to 1000K, a few H2 molecules dissociated forming a mixed liquid of H atoms, H2 molecules, and hydrogen trimers. Electron states near the Fermi level were appeared, which were attributed to the H atoms and the trimers. The electronic properties of the quasi-one-dimensional hydrogen confined in the SWNTs were thus substantially changed.
Effect of the Amorphous Silica Coating Derived by Sol-Gel Processing on the Oxidation Behavior of Ni
Authors: Ren B.Y. , Gao Y.H. , Wang S.J. , Zhang X.J. , Feng N.X.
Published: September 2009

Amorphous silica coating was deposited on the surface of Ni by dip-coating processing from commercial silica sol. Isothermal oxidation of the coated and uncoated specimens at 973 K to 1173 K in air was conducted to investigate the effect of the silica coating on the oxidation behavior of Ni by TGA, SEM and XRD. Results of the oxidation tests showed that the oxidation rate of Ni was reduced greatly due to the applied thin film. The possible mechanism of the effect of thin film on the oxidation of Ni was discussed.
Preparation of Uniform SiO2 Films on Sapphire Dome by r.f. Magnetron Reactive Sputtering
Authors: Feng Li Ping , Liu Zheng Tang , Liu Qi Jun , Li Yang Ping
Published: September 2009

The convex surface of the infrared dome is exposed to the harsh environment of the outside world, and therefore requires a coating which not only increases transmission but is able to withstand rain erosion so as to enhance system performance. This paper deals with the techniques that were developed to deposit a uniform thick SiO2 coating for sapphire dome by radio frequency magnetron sputtering. Results show that average transmission increment in wavelength range from 3 to 5um for the sapphire dome coated on convex surface was more than 4.0%. The transmission non-uniformity over the convex surface of the coated sapphire dome was less than 1.7%.
Superhydrophobic and Highly Oleophobic Cotton Textile: Achieved by Silica Particles and PFPE
Authors: Gao Yu , Feng Shi Jun , Wang Qiang , Huang Yan Gen , Qing Feng Ling
Published: September 2009

The superhydrophobic and highly oleophobic cotton textile was obtained by applying particle -based in situ fabrication procedure with the low toxic perfluoropolyether (PFPE) and the silica particles. The water contact angle and salad oil contact angle on the treated cotton textile surface can be achieved to 156.8 º and 143.3 º respectively. The microstructure of the treated cotton textile surface was revealed by scanning electron microscopy (SEM). And the chemical composition of the treated cotton textile surface was determined by the X-ray photoelectron spectroscopy (XPS) analysis. Thermogravimetric (TG) analysis showed that the weight loss of the treated cotton is less than that of the untreated sample.
Study of the Ion Nitrided Layer on Ti-6Al-4V Substrate
Authors: Li Xiu Yan , Ye Jiao Rong , Tang Bin
Published: September 2009

Titanium alloys are often material of choice for aerospace, chemical and biomedical industries, because of their unusual corrosion resistance, high mechanical strength and low density. However titanium alloys have very poor wear resistance. Hard coatings can be formed on the surface of titanium alloys to improve their tribological property. In this work ion nitriding without hydrogen technique was used to treat Ti-6Al-4V alloy and the nitrided layer was formed on the substrate surface. The fundamental coating properties, such as the phase, component, hardness and elastic modulus were investigated. At the ion-nitriding condition of flux ratio N2/Ar=1:1, pressure 40 pa and substrate temperature 900°C, the nitrided layer was formed. The layer consists of Ti2N and TiN compound. The content of element nitrogen in the nitrided layer gradiently decreases from the the surface to the substrate direction. For a better understanding of the hardness of the nitrided layer, the nano indentation test and microhardness test are both used. The results show that the average values of hardness and elastic modulus for the surface of the nitrided layer are 17.36GPa and 328.81GPa, about 6 times and 3 times respectively as those of Ti-6Al-4V substrate. The hardness of the nitrided layer decreases from the surface to the substrate direction, which corresponding to the content change of element nitrogen. For the result of nano indentation test, when the indentation depth is more than 400nm, the values of hardness and elastic modulus both decrease with the increase of the indentation depth. It is because of the influence of the soft Ti-6Al-4V substrate.
Study of W Metallic Coating Layer on Diamond Surface by Hydrothermal Method
Authors: Xiang Dong , Yin Long Wei , Liu Ke Gao , Jia Li Qun
Published: September 2009

As the diamond surface has higher interface energy, the adhesion of surface and matrix is bad, and it makes the diamond shatter easily. For solving this, the microstructures and properties of the metallic coating on the diamond surface which contains W (tungsten) by hydrothermal method are studied. The different temperatures such as 110 ~140°C and 5h insulating were adopted to be coated in high pressure reactor respectively. The metallic coating on the diamond surface was studied by SEM，XRD and so on. The results show that the continuous and compact coating of Ni and W on the diamond surface is formed by the hydrothermal coating technology at 130°C. The heat treatment temperatures were maintained at 850°C for 1h during the heat treatment process. After the corresponding heat treatment, the better layer coatings, of which thickness is about 10μm, are formed for protecting diamonds and reducing the trend of oxidization. The carbide WC (tungsten carbide) at the interface between the coating and diamond surface is formed. The chemical and metallurgical bonding between diamond and coating is obtained. Because of the coating layers formed and the defects on diamond surface made up, the compress strength of diamond after hydrothermal and heat treatment is enhanced. The compressive strength after hydrothermal and heat treatment is higher than that of un-coating particles(those are 29.45% and 83.64% respectively).
Study on Wheel/Rail Interaction Force Real-Time Monitoring Method Based on Piezoelectric Sensing Technology
Authors: Song Ying , Du Yan Liang , Sun Bao Chen
Published: September 2009

Measurement of wheel/rail contact forces is of importance. Traditional methods for wheel/rail interaction force measurement all need strain gauges on wheel sets and/or rails. Because strain gauges have the performances of zero-drift, poor anti-interference property and instability of test system, they can’t meet wheel/rail force test requirements in high-speed and heavy haul railways. A new method based on PVDF piezoelectric sensing technology is presented for the test of vertical and horizontal wheel/rail force in this paper. Firstly, based on the wheel/rail interaction characteristics, the restriction condition of track and strain sensing principle of PVDF films, principle for measuring vertical and lateral wheel/rail interaction forces is proposed. Then a series of tests were carried out to compare the performance of PVDF strain sensors with the one of strain gauges. The results show that the PVDF strain sensor has better reliability in wheel/rail force monitoring. Finally numerical analysis by Finite Element Method has been carried out to verify the feasibility of the method presented in this paper.
The Biological Behavior of Endothelial Progenitor Cells on Titanium Surface Immobilized by CD34 Antibody
Authors: Chen Cheng , Chen Jun Ying , Li Quan Li , Chen Jia Long , Tu Qiu Fen , Chen Song Mei , Liu Shi Hui , Huang Nan
Published: September 2009

The biological modification of biomaterials surface was an important means for surface endothelialization. In this work, an extracellular matrix-like (ECM-like) surface modification was developed for inducing endothelialization on titanium cardiovascular implant surface. To solve the problem of antibody denaturing caused in the randomly immobilizing, cluster of differentiation 34 (CD34) antibody was directly immobilized on titanium surface using a layer-by-layer self-assembly (LBL) technique. The biological behaviors of the endothelial progenitor cells (EPCs) on modified titanium surface were investigated by in vitro cell culture experiment. The results showed that the avidin, biotinylated protein A and the CD34 antibody were successfully assembled onto the NaOH etched titanium surface. The results of cells experiment suggested that the CD34 antibody immobilized surfaces promoted EPCs attachment and capture in vitro. It was believed that the response of adhesion, proliferation, differentiation of EPCs to titanium surface was regulated by modifying the surface chemistry which controlled the cell-biomaterial interactions. This work provided a surface biomodification means to increase the biocompatibility of titanium-based vascular implant surfaces.
Thermochromic VO2 Thin Film Prepared by Post Annealing Treatment of V2O5 Thin Film
Authors: Liu Dong Qing , Zheng Wen Wei , Cheng Hai Feng , Liu Hai Tao
Published: September 2009

Thermochromic vanadium dioxide (VO2) exhibits a semi-conducting to metallic phase transition at about 68°C, involving strong variations in electrical and optical properties. A simple method was proposed to prepare VO2 thin films from easily gained V2O5 thin films. The detailed thermodynamic calculation was done and the results show that V2O5 will decompose to VO2 when the post annealing temperature reaches 550°C at the atmospheric pressure of less than 0.06Pa. The initial V2O5 films were prepared by sol-gel method on fused-quartz substrates. Different post annealing conditions were studied. The derived VO2 thin film samples were characterized using X-ray diffraction and X-ray photoelectron spectroscopy. The electrical resistance and infrared emissivity of VO2 thin films under different temperatures were measured. The results show that the VO2 thin film derived from the V2O5 thin film annealed at 550°C for 10 hours is pure dioxide of vanadium without other valences. It was observed that the resistance of VO2 thin film with thickness about 600nm can change by 4 orders of magnitude and the 7.5-14μm emissivity can change by 0.6 during the phase transition.
Study on Filtration Performance of Cylinder Metal Rubber Filtering Material
Authors: Guo Ya Dong , Yan Hui , Xia Yu Hong , Jiang Hong Yuan
Published: September 2009

As a novel porous functional material, metal rubber (MR) had many advantages of high loading capacity, high anti-blocked capacity and adjustable porosity with outside pressure made the MR more suitable as filtration material. However, there was no related study and successful application nowadays except in Russia. This study detailed investigated the filtration performance of MR including the influence of wire line diameter, porosity and molding thickness on initial pressure drop under clean liquid condition and their effects on pressure drop-flow rate property and filtration efficiency under contaminated liquid condition. The results indicate that the initial pressure drop increased with the decrease of porosity and wire line diameter, however decreased with the decrease of molding thickness when the flow was constant. Filtration drop increased significantly with the decrease of porosity. MR material made of small diameter wires showed a high filtration efficiency and large pressure drop because of its’ fine micro-pore. Filtration drop rose with the increase of molding thickness however, the filtration efficiency was little affected. These results provide a suitable guideline for further MR filter appliance and MR material research.
Structural and Optoelectronic Properties of Single Crystalline SnO2:Ga Films Deposited on α-Al2O3 (0001) by MOCVD
Authors: Pei Xu An , Ji Feng , Ma Jin , Ning Ti , Song Zhen Guo , Luan Cai Na , Tan Yong Liang
Published: September 2009

12% Gallium-doped tin oxide (SnO2:Ga) single crystalline films have been prepared on α-Al2O3 (0001) substrates by the metalorganic chemical vapor deposition (MOCVD) method. The grown temperatures were varied from 400 to 600°C. According to XRD patterns, the film deposited at 500°C has the best single crystalline structure. Subsequently, 3 to 15% doped films were fabricated at 500°C using the same method, except that Gallium organometallic (OM) source was injected in pulsed-mode for the 3, 5 and 10% -doped films. Then, structural and optoelectronic properties of the films were investigated in detail. The obtained films all have the rutile structure of pure SnO2. Film with resistivity of 1.09×10−2Ω cm, carrier concentration of 8.86×1019cm−3 and Hall mobility of 6.49cm2 v−1 s−1 was obtained at 5% of Ga concentration. The average transmittance for the SnO2:Ga films in the visible range were over 90%.
Cutting Performance of TiAlSiN Coated Cemented Carbide Tool with Post-Deposition Heat Treatment
Authors: Ho Wei Yu , Chen Chi Wei , Wang Da Yung , Ho Woei Yun
Published: September 2009

In this study, TiAlSiN coatings were synthesized by cathodic arc deposition with Ti and Al88Si12 dual cathodes. The as-deposited coatings were following with post-deposition heat treatment in air and nitrogen atmosphere, respectively, at the temperature of 400 oC for 3 hour. The annealing treatment of the TiAlSiN coating has an expected effect on the wear resistance and cutting performance. The TiAlSiN coating subjected to heat treatment in nitrogen atmosphere presented the best oxidation and wear resistance among the tested coatings. The friction coefficient of the TiAlSiN coatings subjected in nitrogen atmosphere at 400oC was decreased due to the effect of the structure modification by increasing hardness. Using thermogravimetric analyzer (TGA), the result turned out the lowest weight change of TiAlSiN coating after annealing treatment in air if compared to that of all the coatings. The reason my be due to the oxide layer formed on the coating surface acted as a protective layer. Cutting test on the hardened steel with mist oil lubricants, the TiAlSiN-coated WC-Co tool with annealing treatment in nitrogen provides the best wear resistance at the cutting edge.
Effects of Nano-Al2O3p on Thermal Shock Behaviors of NiCoCrAlY Coatings by Laser Cladding
Authors: Wang Hong Yu , Zuo Dun Wen , Sun Y.B. , Huang Ming Min
Published: September 2009

NiCoCrAlY coatings strengthened by different content of nano-Al2O3p, using crosscurrent CO2 laser, were prepared on Ni-based superalloy substrates, and thermal shock behaviors of these coatings were investigated by cycling between 1050°C and room temperature (forced water quenching).The results show that the thermal shock resistances of nano-Al2O3p-added coatings are definitely better than that without adding nano-Al2O3p. Among the nano-Al2O3p-added coatings, the coating added with 0.5wt% nano-Al2O3p performs best. After 10 thermal shock cycles, the spalled and spalling area in the oxide scale of the no-nano-Al2O3p coating reaches up to 27.7%, and the main failure form of the oxide scale is an expanding unit-spalling type in thermal shock cycles. While the area in the oxide scale of nano-Al2O3p-added coatings is only 10%~60% to the no-nano-Al2O3p one, and the failure of these oxide scales is mainly in the form of unit-spalling type. After 100 thermal shock cycles, many cracks turn up in the cross-section of the no-nano-Al2O3p coating, including propagating crack and internal crack. While no internal crack appeared in nano-Al2O3p-added coatings, and the propagating cracks are smaller than no-nano-Al2O3p one.
Experimental Study and FEM Analysis on Ceramic Composite Coating
Authors: Wang F.H. , Jiao Anyuan , Yang S.Q. , Gao X.Q.
Published: September 2009

Using gravitational separation Self-propagating High-temperature Synthesis(SHS) process, ceramic composite coating was made in large cross-section rectangular pipes and hemming plate, which can be use directly and also can be cut into the ceramics clad steel plate. The experimental results showed that the surface of ceramics coating, for using section steel as core of large cross-section rectangular pipes or hemming plate combination pipes, is glossy, and its thickness is among 1.5~3.5mm. Metallurgical bonding between steel substrate and ceramics coating can not come into being and the mode of their joint is mainly mechanical bonding. The cooling process of the ceramic-lined square steel tubular was simulated by use of ANSYS. Temperature-time curves of composite rectangular pipes with different thickness and residual stress distribution were calculated, and the reason for creating bonding force. These provided a reference to choose the technologic parameters.
Fabrication of Mesoporous N-TiO2 Membrane and its Spectral Characteristics
Authors: Zhou Zhi , Wang Wei Gang , Huang Wei , Jing Wen Heng , Xing Wei Hong
Published: September 2009

Ceramic ultrafiltration membrane, pore size from 2 to 50nm, is of growing interest in separation and purification processes because of their higher chemical, thermal and mechanical stability compared to organic membranes. TiO2 mesoporous membranes have gained tremendous popularity due to their photocatalytic activity and because they possess high water flux and chemical resistance. In recent years, visible-light-induced nitrogen-doped titanium dioxide (N-TiO2) materials have been attracted extensive attention. We synthesized asymmetric N-TiO2 membrane based on this material via sol-gel method, in which titanium tetrabutoxide was used as Ti-precursor and formamide as nitrogen resource. A -alumina support with macropores was used and its diameter, thickness and pore size were 28.5 mm, 2.2 mm and 0.10μm, respectively. The alumina supports were pretreated using PVA to prevent permeation of sol into the supports. Sol was coated on this treated supports, and then formed gel under 60°C. The resulting membrane posseses a pore size of 4nm and its pure water permeability is 3.3L/(m2•h•bar). The influences of formamide on the microstructrue and the spectral characteristics were also analyzed by means of BET, UV-vis. As indicated by results, when the molar ratios of formamide and titanium terabutoxide were near 4, the materials had excellent visible light absorption, the absorption band was shifted to about 545nm and the band gap was reduced to 2.65eV. The band gap was 0.55eV less than that of pure TiO2. The membrane has potential application in purifing of micro-polluted surface water under visible-light environment.
Effect of Heat Treatment on Optical Properties of Cold Spray TiO2 Coated Glass
Authors: Yang Jing Kai , Zhao Hong Li , Liu Yan Li , Zhang Fu Cheng
Published: September 2009

The cold spray TiO2 thin films were deposited on 5mm-thick float glass substrates using the sol containing nano-anatase TiO2. The effects of different heat treatment temperatures on optical properties were discussed. The properties of xerogel powder were analyzed using TG-DSC, the morphology and structure of TiO2 thin films were characterized by FESEM and XRD, the transmittance and absorption of TiO2 coated glass were investigated by UV-vis spectrophotometer. The results reveal that TiO2 in the film is still anatase phase after heat treatment at 350°C and 500°C. With the annealing temperatures increasing from 20°C to 500°C, the average crystal size increases just from 21.4 nm to 23.9nm, UV absorption of TiO2 coated glass increases from 2.2 to 2.7, visible light transmittance is high to about 80%.
Anti-Oxidation Behavior of Alumina Coating on Carbon Fibre by Sol-Gel Method
Authors: Zhang Yu Dong , Su Xun Jia , Hou Gen Liang , Guo Feng
Published: September 2009

Alumina coating on carbon fibre were prepared by Sol-gel method, and characterized by thermal gravimetric analysis, X-ray diffraction and scanning electron microscopy. Affected factors such as coating times, oxidation temperature and time were investigated. The results show alumina coatings on carbon fibres are crack-free with a smooth surface, therefore would improve anti-oxidation of carbon fibre significantly. Thickness is one of the most important factors on anti-oxidation of alumina coating, and in this work, thicker coatings have better anti-oxidation quality.
Study on Barium Strontium Titanate Thin Films Integrated on Si Substrates by Laser Molecular Beam Epitaxy
Authors: Zhou X.Y. , Zhou Yun , Wang G.Y. , Wang Y. , Chan Helen Lai Wah , Choy C.L. , Cao Guo Zhong
Published: September 2009

(Ba,Sr)TiO3 thin film has been deposited on Si (001) wafer with the SiO2 layer as the block layer through laser molecular-beam epitaxy using an ultra thin Sr layer as template. X-ray diffraction measurements and the cross-sectional observations under transmission electron microscope indicated that BST was well crystallized. This deposition of Sr layer is considered to remove the thin SiO2 layer to produce a layer, which is crystallized and has a lattice structure matching with that of perovskite BST. The maximum in-plane dielectric tunability is calculated to be 50% at 1 GHz under a moderate DC bias field of 13.3 V/µm. This BST/Si structure is believed to be a promising candidate in the development of ferroelectric BST-based microwave devices.
Wear Characteristics of Magnetorheological Fluid under Boundary Lubrication
Authors: Sohn Jung Woo , Choi Seung Bok , Lee Chul Hee , Cho Myeong Woo
Published: September 2009

This experimental investigation presents wear characteristics of magnetorheoloigcal (MR) fluid under boundary lubrication contact condition. Three different specimens; aluminum, copper and steel pins are prepared and wear test is performed under consideration of several operational factors such as normal load, sliding distance, and sliding speed by using pin-on-disk test equipment. Wear rate and friction coefficients of the MR fluid are experimentally evaluated with respect to the sliding ranges. Microscopic surface and roughness changes of the worn surface of pin specimens are also analyzed by using the scanning electron microscope (SEM). In addition, Energy Dispersive X-ray Spectroscopy (EDS) analysis is conducted and chemical changes are investigated.
The Effect of Annealing Atmosphere on Electrical Properties of BST Thin Films Prepared on Copper Foils
Authors: Fan Yan Hua , Yu Shu Hui , Yu Shuai Qin , Dong Li Hua , Zhang Wei Ke , Yin Yan Sheng
Published: September 2009

Ba0.7Sr0.3TiO3 (BST) thin films have been prepared on copper foils via sol-gel method in almost inert atmosphere containing different level of oxygen which was achieved by flowing high purified argon with the varied rate from 0.3 L/min to 2.0 L/min. X-ray diffraction pattern of the BST thin film exhibits dominant perovskite phase. SEM images reveal good crystallization and much dense structure of the thin film. The BST thin film annealed at almost inert atmosphere by flowing the high purified argon at the rate of 0.5 L/min, exhibits highest dielectric constants which are 1549.65 and 1350.86 at the frequency of 10 kHz and 1 MHz, respectively. Additionally, the film also shows optimized ferroelectric behavior and low leakage current density. The mechanism of the annealing atmosphere on properties of BST thin films was investigated.
Preparation of Cu2ZnSnS4 Thin Film by So-Gel Spin-Coated Deposition
Authors: Yeh Min Yen , Lee Chin Cheng , Wuu Dong Sing
Published: September 2009

In this work Cu2ZnSnS4 (CZTS) suitable for the absorption layer in solar cells was successfully prepared by sol-gel spin-coated deposition. CZTS precursors were prepared by using solutions of copper (II) chloride, zinc (II) chloride, tin (IV) chloride, and thiourea. The CZTS with texture surface structures, resulting from 3 times of stacks through the cycles of spin-coated and synthesized (at 320 °C) processes, is found to be merged well together, and the thickness of the CZTS reaches ~ 3 μm. The kesterite crystallinity of the CZTS designated from the x-ray diffraction of (112), (200), (312), and (322) planes of CZTS were obtained. The optical-energy gap of the CZTS is about 1.5 eV. The average optical-absorption coefficient of the CZTS is ~ 2.4 x 104 cm-1, and the high absorption band of the CZTS covers most of the solar irradiation spectrum. This makes the CZTS the most potential material for solar cells. The chemical composition Cu:Zn:Sn:S = 30:14:16:40 of the CZTS is obtained at a synthesized temperature of 320 °C.
Preparation of Super-Hydrophobic Polyethersulphone Membrane by Sol-Gel Method
Authors: Sun Xu Dong , Li Guang Fen , Zhang Yu Zhong , Li Yu Xiang , Li Hong
Published: September 2009

Super-hydrophobic membrane has received extensive attention from basic theories and practical applications. The properties of the super-hydrophobicity of membrane are strongly dependent on the prepared method, which is attracting increasing concerns worldwide. The properties of super-hydrophobic membrane are dominated by many factors including the chemical composition and the morphology of the surface. In this work, a simple method to fabricate super-hydrophobic membrane with weak hydrophilic polyethersulphone (PES) via a sol-gel process is reported. The weak hydrophilic PES membrane was used as a membrane-based, which was dipped into precursor Sol firstly. After heat treatment, the membrane was dipped into the fluoroalkylsilane solution and then dried by again a heat treatment. The super-hydrophobic and porous PES membrane was characterized by Fourier-Transform Infrared Spectrometers (FTIR), contact angle goniometer, atomic force microscope (AFM). The results showed that the contact angle of super-hydrophobic membrane was up to 154°treated by precursor sol for 20min and fluorinated for 20h. The hydrophobic functional groups on the membrane surface were fluorinated groups (-CF3, -CF2, and -CF) and -CH3. The AFM images results showed the membrane surfaces have micro-/nanometer crater-like protrusions. Those protrusions contributed for the rough surface of membrane, and the root mean square (rms) roughness was about 350.9nm. The hydrophobic groups and the surface roughness structure together lead to the super-hydrophobicity of the porous membrane.
Optical and Electrochromic Properties of Sol-Gel Deposited Mixed MoO3-WO3 Thin Films
Authors: Sun Xi Lian , Chen Ai Hua , Zhang Hai Zhong , Cao Hong Tao
Published: September 2009

Mixed molybdenum-tungsten oxides of varying stoichiometry (MoxW1-xO3, 0 < x <1) were prepared by sol-gel deposition from peroxo-polymolybdotungstate solutions onto conductive fluorine doped tin oxide (FTO) coated glass substrates. The compositional and structure properties were characterized for MoxW1-xO3 films annealed at 450°C using energy-dispersive spectroscopy and X-ray diffraction measurements. The optical transmittance of the films were recorded with respect to air in the reference beam in a UV-Vis-NIR spectrophotometer. The transmittance modulation of the mixed oxide films were enhanced compared to the pure WO3 film and very broad spectral modulation features were observed for mixed oxide. Cyclic voltammetry and chronoamperometry measurements were conducted to estimate ion storage capacities and reversibility of the films during the coloring/bleaching process for the mixed metal oxide films in an electrolyte solution of lithium perchlorate in propylene carbonate. The subtle interplay between structural and compositional properties due to the uniform mixing of Mo and W oxide components shows that electrochromic and lithium ion transport properties are moderately enhanced relative to those of single-component WO3.
A DFT Study on the Geometric Structure and Magnetic Properties of (FeAl)n (n≤4) Clusters
Authors: Yu Shuai Qin , Fan Yan Hua , Dong Li Hua , Yin Yan Sheng
Published: September 2009

Theoretical study on the geometric structures and magnetic properties of small (FeAl)n
(n=1-4) clusters has been carried out at the BPW91 level. In all the (FeAl)n clusters, the iron atoms are brought together, yielding a maximum of Fe-Fe bonds, and the aluminum atoms are located around a Fe core with a maximum of Fe-Al bonds which is different the bulk ordered FeAl alloy dominated by the Fe-Al bonds. As opposed to the bulk FeAl with non-magnetic, the small nano-clusters are highly magnetic moment dominated by Fe-Fe clustering.
Preparation and Magnetic Properties Studies of Granular FePt Composite Films for High-Density Magnetic Recording
Authors: Chen Sheng Chi , Sun T.H. , Kuo T.Y. , Kuo Po Cheng
Published: September 2009

Granular (FePt)100-x–(NiO)x nanocomposite thin films with x in the range of 0 – 42 vol.% were fabricated on a natural-oxidized Si(100) substrate. It is found that both the coercivity and FePt domain size decrease with increasing NiO content for the (FePt)100-x–(NiO)x films. When the FePt-NiO nanocomposite film with NiO content of 10.4 vol.% is post-annealed at 750 °C with a high heating ramp rate of 100 °C/sec, the in-plane coercivity (Hc//) and perpendicular coercivity (Hc⊥) of the FePt films are 6.4 and 5.5 kOe, respectively. On the other hand, we used conductive atomic force microscope (CAFM) to confirm that the NiO compound is distributed at grain boundary of FePt grain that will constrain the domain size of FePt and obtain isolated magnetic domains. These results indicate that NiO addition is beneficial to enhance recoding density and reduce media noise of the FePt magnetic film.
Surface Morphology and Structure Study of Titanium Dioxide Thin Films Deposited on PET Substrates
Authors: Zhang Yu Hui , Ji Quan , Pei Xi Hua
Published: September 2009

Titanium dioxide (TiO2) thin films were deposited by rf magnetron sputtering, using a Ti target (purity 99.99%), on poly (ethylene terephthalate) (PET) substrate. Argon and oxygen were used as the working and reacting gas, respectively. The surface morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the film composition and structure by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Uniform and compact TiO2 nanoparticles with diameter about 50 nm were deposited on PET substrates within 2 minutes. Many nano-sized particles aggregated and formed larger clusters after 5 minutes. The size of the clusters increased with increased sputtering time. The particles grew perpendicular to the substrate, and the surfaces of the films were smooth and undulate. The Ti2p peak was resolvable into the three valence species Ti4+, Ti3+ and Ti2+. The O/Ti ratio varied with the Ar: O2, ratio, the optimum value of which was in the range 4-8. The TiO2 films deposited on PET substrate were amorphous.
Characterization and Annealing Effects of Titanium Dioxide Films Prepared by a Sol-Gel Process
Authors: Lien Shui Yang
Published: September 2009

Titanium dioxide (TiO2) has received intense interest because of the numerous technical applications. In this work, the TiO2 thin films were deposited on Si substrates by spin coating from a TiO2 solution prepared by a sol-gel method. It was found that the TiO2 film properties strongly depended on the post annealing conditions. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometer (FTIR) were used to investigate the compositional and chemical states of the thermal-treated TiO2 samples. For the TiO2 samples annealed in atmosphere, the contents of -C and -OH bonds increased when the process temperature increased. From XPS measurement, the atomic concentrations of carbon and oxygen in the film are determined to be approximately 46% and 37%, respectively. However, for the samples annealed in oxygen, the contents of -C and -OH bonds were found to decrease when the anneal temperature increased. The concentrations of carbon and oxygen in the film were approximately 11% and 59%, respectively. To further investigate the behavior, the in-depth concentration profile of carbon was measured for the TiO2 samples under different etching time. It was found that the carbon concentration drastically decreased from 11% (surface) to 0.2% (near the interface). The result indicates that the pure TiO2 film could be obtained by sol-gel coating with a suitable annealing process.
Atomic Structure of Hydrous Ruthenium Oxide Coating on Ti and CNT Substrate by Cathodic Deposition Method
Authors: Huang H.S. , Peng W.Z. , Lin Yu Li
Published: September 2009

In this study, hydrous ruthenium oxide was deposited on titanium(Ti) and carbon nanotube(CNT) substrate by cathodic deposition method. Combination of amorphous and nanocrystalline structure of hydrous ruthenium oxide was investigated by high resolution electron microscopy. The measured capacitance was found keeping nearly constant through charge/discharge processes for hydrous ruthenium oxide coating on Ti substrate. On the other hand, thin and uniform layer of hydrous ruthenium oxide coating can be deposited on CNT substrate. The thickness of the coating layer was found less than 10nm. Combination of amorphous and nanocrystalline structure of hydrous ruthenium oxide was also investigated on this specimen. The consumption of coating was found very effective for this specimen after 105 charge/discharge cycles which lead to the tremedenously decreasing in the measured capacitance.
EBSD Study of Crystallographic Identification on Fe-Al-Si Intermetallic Phases in Aluminide Coatings on Mild Steels
Authors: Cheng Wei Jen , Wang Chaur Jeng
Published: September 2009

Mild steels were coated by hot-dipping in molten aluminum and aluminum-silicon baths at 700 °C for 180 seconds. Phase identification of the Fe-Al or Fe-Al-Si intermetallic compounds in the hot-dipped aluminide steel was carried out by using a combination of scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and electron backscatter diffraction (EBSD). The results showed that the aluminide layer of the hot-dipped aluminum steel possessed a thicker intermetallic layer than that of the hot-dipped aluminum-silicon steel which was composed of minor monoclinic FeAl3 and major orthorhombic Fe2Al5. The intermetallic layer of the hot-dipped aluminum-silicon steel was composed of not only the same FeAl3 and Fe2Al5 phases in the hot-dipped aluminum steel but also Fe-Al-Si intermetallic compounds of hexagonal Al7Fe2Si and tetragonal (Al,Si)5Fe3.
Glass Fibers Covered with TiO2 Thin Films by Sol-Gel Method as a Photocatalyst Reactor to Degradation Toluene
Authors: Lin Ching Hsing , Chang Chen Yu , Chang Yu Jie , Lee Jyh-Wei , Hwa Mei Yin , Lee Yao Chuan
Published: September 2009

TiO2 thin films obtained by sol-gel and dipping deposition on glass fibers substrates followed by thermal treatment was used in this works. In an attempt to understand the structure and the morphology of TiO2 sol-gel thin films, analysis by X-ray diffraction (XRD) and scanning electron microscopy (SEM) are reported. Degradation of toluene under 365 nm light illumination was conducted to evaluate the photocatalytic ability of the TiO2 thin films. A special design of glass reactor allowed the UV lamp to be located in the center of the reactor. The photocatalyst reactor was then filled with TiO2 thin films/glass fibers substrates to exams the photocatalysis of toluene vapor ranged from 10 to 1,000 ppmv. Toluene depletion was sampled by gas chromatography (GC). The results showed that the photocatalytic performance of the reactor had high toluene depletion efficiency of 99.9% under 20 ppmv, and the efficiency decreased when toluene concentration were 100 and 1,000 ppmv. The improvement of the photocatalytic activity was ascribed to the fibers-based reactor provides a significantly huge surface area of the TiO2 thin films. These results will be useful and assist engineers to design photocatalyst reactors for the VOCs removal.
The Photoelectrochemical Characteration of Porous Titania Dioxide Thin Films Prepared by PEG-Assisted Sol-Gel Method
Authors: Wang Ai Ping , Yin Yan Sheng , Wang Hong Feng , Zhu Zhi Bin , He Ming Hui
Published: September 2009

Nanocrystalline titania porous films were prepared on ITO and glass substrates by polyethylene glycol（PEG）-assisted sol-gel method using Ti(C4H9COO)4 as precursor, ethanol as solvent and NH(C2H2OH)2 as chelating agent and PEG 2000as a template. When the amount of polyethylene glycol is within the range of 0～2. 0g/L ,. The characteristics and microstructure of films as well as the chemical and physical changes taken place during so-gel and heat treatments were analyzed by XRD, SEM and Emission spectra. The Cyclic voltammetry which measurements the films by illumination with a high pressure mercury lamp are employed to analyze photoelectrochemical property the porous titania thin films. The effects of precursor concentration and PEG 2000 contention the characteristic of films were discussed. The Cyclic voltammetry experiment under UV light irradiation indicated that the pores in the TiO2 thin films enhanced its photoelectrochemical activity; the size of the pores thin films obviously affected the photo-current exchanged rate of titania films.
Study on Resistance to Sulphate Attack of Polymer Modified Sulphoaluminate Cement
Authors: Lu Ling Chao , Li Yun Chao , Wang Shou De , Guo Xiang Yang
Published: September 2009

Styrene-acrylic emulsion was synthesized by pre-emulsification and semi-continuous emulsion polymerization, with styrene and butyl acrylate as monomers. The effects of initiator dosage and ratio of polymer to cement on durability of polymeric sulphoaluminate cement were investigated. SEM, pore structure and resistance to sulfate attack were also studied. The results show that the total porosity of the polymer sulphoaluminate hardened cement paste is lowest when P/C is 7.5%. Innocuous pores of the hardened paste are the least when P/C is 5.0%. It shows that polymer particles can spread around the cement paste, and polymer particles, aggregates, hydration products and pores come into being a compact mass. Flexural strength is higher when initiator dosage is 5‰ than that is 4‰. Flexural strength is the highest when initiator dosage is 5‰ and P/C is 7.5%, in other words, the performance of resistance to sulfate attack is best when initiator dosage is 5‰ and P/C is 7.5%.
The Preliminary Study on Antifouling Mechanism of Shark Skin
Authors: Peng Yan Lei , Lin Cun Guo , Wang Li
Published: September 2009

Biofouling, which is the result of marine organisms settling, attaching, and growing on submerged marine surfaces, is a usually-seeing phenomenon for the ocean-going ships and submarines. And, it can decrease the range, speed, and maneuverability of these vessels and increase the fuel consumption. Contrarily, the sharks remain largely free of bioadhesion despite spending their entire lives submerged. The sharks have placoid scales, which consist of rectangular base embedded in the skin with tiny spines that poke up from the surface. It is found that this special structure can make great deal of function for antifouling. In our report, parallel works for antifouling mechanisms were motivated by Triakidae shark feeding, observations on shark skin, and the experiments of benthic diatoms adhesion and Mytilus edulis byssus attachment. And, the optical configurations were acquired by using 3D video microscope and environment scanning electron microscope (ESEM). The results showed that, the benthic diatoms adhesion on the naked skin of living sharks was obviously fewer than the dead ones, and could not be found on the surface of placoid scales. As the time progressed, the rate of Mytilus edulis byssus attachment reduced gradually. It was thought that, the water turbulent boundary on the surface was changed greatly and innumerable minimal vortex was generated when the water flow on the shark skin. The strong exchange of momentum in a turbulent boundary layer would produce high-speed lumps approaching the surface, which could develop strong shear stress. Benthic diatoms and mussel could not attached firmly or be cleared easily when the shear stress became stronger than the adhesion power of these organisms. After finding the real working mechanism of antifouling for sharks, it could be used to direct the progresses of synthesizing biomimetic coatings or materials with antifouling performance in the future.
Study of the Inhibition Mechanism of Imidazoline Derivative Inhibitor on CO2 Corrosion for Q235 Steel
Authors: Wang Bin , Du Min , Zhang Jing
Published: September 2009

Imidazoline derivative inhibitors are successfully used in oil-gas field for CO2 and H2S corrosion. The inhibition performance and inhibition mechanism of imidazoline with thioureido to prevent corrosion of steel in saltwater saturated with CO2 were studied by polarization curves and electrochemical impedance spectroscopy (EIS), in the meantime, quantum chemical analysis was used to analysis the results. The results of electrochemical measurements indicated that the inhibitor belonged to mixed-type inhibitor which mainly inhibited anodic process and worked as “negative catalysis”. The inhibition efficiencies increased then decreased with the increase in inhibitor concentration. The electrochemical results have also been supplemented by quantum chemical analysis. It was found that the chemical adsorption of the imidazoline with thioureido molecule on Q235 steel depended on the imidazoline ring and thioureido, thus the inhibitor had good corrosion inhibition.
Chloride Ion Diffusion of Phosphoaluminate Cement Concrete
Authors: Ding Zhu , Xing Feng , Zhang Ming , Liu Peng
Published: September 2009

Penetration and diffusion of chloride ions in concrete can lead to the corrosion of steel bar and shorten the service life of concrete structures. Phosphoaluminate cement (PAC) is a new cementitious material which has many special properties compared to Portland cement (PC). In the study, chloride ion diffusion in PAC concrete was tested with RCM method. The phase composition and morphology of hydration products, pore volume of hardened paste cured for 28d were analyzed with X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP). The results show that chloride ion diffusion coefficient of PAC concrete is much lower than that of Portland cement concrete under the same test conditions. The hydration products of PAC are main micro-crystalline phase and gel of phosphate and/or phophoaluminate, which formed a dense microstructure. There is no calcium hydroxide produced in the PAC hydration system. In hardened PAC paste, chloride ions might replace the atom group [OH] - and [PO4]3- of hydrates and become stable compounds. The resistance to chloride ion diffusion of PAC concrete will increase with the hydration age, because its microstructure becomes denser with the hydration age increasing.