bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Mechanism for the Enhancement of the Catalytic Activity of Graphene As a Support Material for Oxygen Evolution Reaction Based on Mixed Potential Theory
Authors: Reda Mahmoud R. , Reda Ghazi 
Published: February 2020

Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable-energy technologies including fuel cells and water splitting.[1] Currently, there is intense research for new catalysis systems that are highly efficient, low cost, and environmentally friendly in light of the global energy issues.Efficient electrocatalysts for oxygen evolution reaction (OER) represent a critical component in various energy technologies, such as solar cells, metal–air batteries and hydrogen generation from water splitting.[2]
The applicability of a composite of graphene with electroactive material as catalyst for OER is rapidly growing. The growth was due first to the enhancement of the rate of OER which was observed by many researchers when composing the electroactive catalyst with graphene. Second due to the fact that the production cost of graphene in large quantities is much lower than that of carbon nanotubes. Third to the remarkable properties of graphene reported so far include high specific surface area,excellent mechanical strength and fracture strength, unparalleled thermal and electricity conductivity excellent pliability (the quality of being easily bent) , and unprecedented impermeability, plus fascinating electronic properties such as the quantum Hall effect.[3]
Many researchers discovered that the there is an enhancement to the rate of OER when graphene is used as a support for the OER catalyst [4,5]]
Here we show that the mixed potential theory[5] predict that the enhancement of the electrode reaction require two important factors.The first is a large surface area of graphene and the second is the high electric conductivity of graphene which implies that graphene acts as a cathodic electrode conjugating the anodic reaction (OER).
[1] S. Ratha et al. Solid State Electrochem, 20,285 (2016).
[2] Z. Jiang et al. J. Mater. Chem. A, 4, 5877 (2016).
[3]Novoselov, K. S.; Geim et al. Science 2004, 306, 666–669.
[4] D. Chen et al.Chem. Soc. Rev., 39, 3157 (2010).
[5] S. Ghosh et al. Inter J. of hydrogen energy 42, 4111(2017).
[6] G.S. Frankel, Chapter 2, Page 17, Fundamentals of Corrosion Kinetics,
file:///home/chronos/u-eb61a46a79ae3aa8b759186c1deadc9a7f33a7e5/Downloads/9789401775380-c2.pdf
Polyoxometalate Chemistry in Carbon Nanotubes
Authors: Newton Graham N. , Jordan Jack , Lowe Grace , Walsh Darren Anthony , Khlobystov Andrei N. 
Published: February 2020

Polyoxometalates (POMs) have received considerable attention in recent years due to their rich redox properties and potential applications in energy storage.1 Due to their discrete nature, the use of POMs as components in energy storage devices relies on their stable combination with conductive supports.2 Carbon nanotubes (CNTs) are stable, hollow cylinders made entirely of carbon. These nanostructured carbons are highly conductive, mechanically strong and can be functionalized.3 By encapsulating molecular materials within CNTs, their properties can be enhanced.
This work describes the first report of the encapsulation of the Keggin [PW12O40]3- and Wells-Dawson [P2W18O62]6- heteropolyanions within carbon nanotubes (CNTs), along with detailed structural, chemical and electronic characterization. Transmission Electron Microscopy (TEM) confirms the presence of encapsulated POMs, as well as providing the necessary energy to perform observable chemical transformations within the CNT. Access to POM redox properties from within the CNT upon encapsulation is described, and the POM electrochemistry is shown to be stabilized across a greater range of conditions and cycles than typically possible. Investigations using Raman spectroscopy probe the electronic coupling between the host and guest, showing electron transfer between the two.

Sadakane, M.; Steckhan, E., Electrochemical Properties of Polyoxometalates as Electrocatalysts. Chem. Rev.
1998,
98 (1), 219-238.

Song, Y.-F.; Tsunashima, R., Recent advances on polyoxometalate-based molecular and composite materials. Chem. Soc. Rev.
2012,
41 (22), 7384-7402.

Miners, S. A.; Rance, G. A.; Khlobystov, A. N., Chemical reactions confined within carbon nanotubes. Chem. Soc. Rev.
2016,
45 (17), 4727-4746.
Carbon Spaghetti from the Reduction of Molten Carbonate Salts
Authors: Hughes Matthew , Allen Jessica A , Donne Scott W 
Published: February 2020

The synthesis of new forms of carbon is of great use in the production of many new materials and comforts of modern life. The synthesis of carbon has previously been achieved through many paths, however a path that has been given some major interest in recent years as a medium temperature method of producing carbon products with interesting physical and electrochemical characteristics is the reduction of molten carbonate salts to form value-added carbon products [1]. Of these products, it has recently been noted that carbon nanofibers may form during the reduction of molten Li2CO3 in the presence of trace elements of transitional metals [2]. If carbon nanotubes can be formed through the reduction of molten carbonates it would be of great benefit for many fields, embodying a cheap, low energy cost method of producing these materials. This research investigates the formation of carbon tube structures from molten Li2CO3-K2CO3-Na2CO3 eutectic at 600°C-700°C using copper substrates (Figure 1). Findings suggest that optimal conditions for nanotube synthesis involve nucleation and growth steps, which occur concurrently with the formation of further carbon phases. The formed fibers are hollow tubes which may be capped unless broken, with two major size distributions, thick tubes and thin tubes. The thin tubes have diameters in the order of 300-400 nm.
[1] Hughes, M.A., J.A. Allen, and S.W. Donne, Carbonate Reduction and the Properties and Applications of Carbon Formed Through Electrochemical Deposition in Molten Carbonates: A Review. Electrochimica Acta, 2015. 176: p. 1511-1521.
[2] Ren, J., et al., One-Pot Synthesis of Carbon Nanofibers from CO2. Nano Letters, 2015. 15(9): p. 6142-6148.

Figure 1
Novel Process Development of Pyrolytic Carbon Devices
Authors: Gastian Loren , Finnegan Patrick Sean , Washburn Cody M , Dyck Christopher , Burckel D Bruce , Blecke Jill , Rector Michael N , Pfeifer Kent B. , Satches Michael R. 
Published: February 2020

Sandia National Laboratories has developed novel approaches to integrate pyrolytic carbon as a viable alternative material in microelectronic devices. Our work demonstrates fabrication of simple single layer and multiple layer devices, targeting future microelectronic applications.
We demonstrate a patterned photoresist on a silicon (Si) substrate, followed by a high temperature bake, and a xenon difluoride Si etch release process as a simple fabrication approach. Loading nanomaterials into the pre-pyrolized polymer establishes the capability to tune specific mechanical and electrical properties. Micromachining blanket carbon films using a dry etch process, allows for precise critical dimension control, and the ability to integrate carbon into complex multilevel device processing. Carbon is durable, adaptable, highly conductive, inexpensive, and easy to produce.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. Department of Energy or the United States Government.
Figure 1) SEM image of cantilever array dry etched and released in xenon difluoride.

Figure 1
Nanoscale Electrochemical Imaging of Aligned Semiconducting and Metallic Single-Walled Carbon Nanotube Bundles
Authors: Kumatani Akichika , Okada Takeru , Yasufumi Takahashi , Shimura Miyu , Shiku Hitoshi , Samukawa Seiji , Matsue Tomokazu 
Published: February 2020

Carbon nanotubes have been studied in the variety of research fields from electronic devices to energy harvesting applications [1]. In general, their unique properties come from their ideal one-dimensional structure and tremendous metallic or semiconducting behavior depending upon their chirality. For energy application, it is an important issue to develop a good separation technique for the metallic and semiconducting single-walled carbon nanotubes (SWNTs) in large volume and to understand their electrochemical activities of both types of nanotubes. Recent progress for separation between metallic and semiconducting of has been developed. For example, a gel-based separation technique reported by Tanaka and co-workers [2]. Also, Unwin’s group has revealed the electrochemical activities for each type of the individual SWNT by scanning electrochemical cell microscopy [3].
In this study, we have at first created aligned SWNT bundles by dielectrophoresis [4] using by the commercially available suspension created by a gel separation technique. The aligned nanotube samples were prepared from either semiconducting or metallic nanotube suspension. Then, scanning electrochemical cell microscopy with a single-barrel nanopipette [5] was applied to each sample for the detection of the existence of the other property of the nanotube, referring to the difference in electrochemical activities between semiconducting and metallic nanotubes [3].
[1] M. F. L. De Volder et al., Science 339, 535, (2013). [2] T. Tanaka et al., Nano Lett. 9, 1497 (2009). [3] A. G. Guel et al., Nano Lett., 14, 220 (2014). [4] R. Krupke et al., Science 301, 344 (2003). [5] Y. Takahashi et al. Nat. Comm. 5:6450 (2014).
(Invited) Thixotropic Gel Electrolyte Consisting of Imogolite and Ionic Liquid
Authors: Shikinaka Kazuhiro , Tominaga Yoichi 
Published: February 2020

Electrolytes are fundamental materials that have been used in various industrial fields, for example, in batteries. Liquid electrolytes, though widely used, lack safety and moldability because of the inclusion of organic solvents and the inherent fluidity. The superior safety and moldability of solid electrolytes make them possible alternatives to liquid electrolytes. However, the ionic conductivity of solid electrolytes is lower than that of liquid electrolytes. Recently, a gel-type electrolyte, which combines the high ionic conductivity of liquid electrolytes and the safety of solid electrolytes, has been reported. However, the gel-type electrolyte needs various specific techniques for molding.
In this presentation, we report a quasi-solid electrolyte comprising a transparent thixotropic gel swelled by an ionic liquid (IL) that is formed by a framework of cylindrical inorganic ‘‘imogolite’’ nanotubes. ILs are molten salts consisting of weakly coordinated cations and anions; ILs exhibit melting points below 100 ºC, low vapor pressure, high thermal stability, and high ionic conductivity. Thixotropy as well as stimuliresponsive liquid/solid phase transitions are important for molding of materials in numerous industrial processes (for example, paints and ceramic sols). An application of thixotropic nature to electrolyte will realize its free molding in accordance with the shape of the conduction interface that is difficult for ordinary liquid/solid/gel electrolytes.
Imogolite (IG) is nanotube-like clay mineral, which has a rigid fibrous structure in the form of a single-walled aluminosilicate cylindrical inorganic polymer, with the composition (HO)3Al2O3SiOH. The outer and inner surfaces of IG are covered with Al(OH)2 (proton-capturing) and Si(OH) (proton-releasing) groups, respectively. Recently, we found that mixtures of IG and dicarboxylic acids (DAs) in water resulted in the formation of homogeneous gels, consisting of networked IGs at a mixing ratio, molar ratio of –Al(OH)2 vs. carboxyl groups in DA, of 1 : 1. The gels consisting of IG and DA such as maleic acid (hereafter denoted ‘‘IG–DA gel’’) exhibited hysteresis-free thixotropic behavior. In this study, the thixotropic electrolyte was obtained by substitution of water in the IG-DA gel to ionic liquid.
Because of its transparency, moldability, thermal stability, and high ionic conductivity (Figure), the thixotropic gel electrolyte can be used in various applications such as free-moldable conductive and anti-icing coatings, and battery electrolytes. The transparency of the quasi-solid electrolyte would prevent damage to the base materials. Furthermore, specific abilities of the IG thixotropic gel, such as macroscopic supramolecular chiral ordering of the IG nanotubes and electrorheological responsiveness of the IG, indicate significant potential for the use of these IG–DA–IL based quasi-solid electrolytes as chiral sensing materials, multi-stimuli-responsive actuators, etc.

Figure 1
(Invited) Volume Phase Transition of NIPA Gels and Its Relation to the Inhomogeneity Caused By Extremely Multifunctional Crosslinker
Authors: Nishio Izumi , Saito Azusa , Kamiya Suguru , Okada Shunsuke , Nojima Megumi , Takashima Akito 
Published: February 2020

NIPA-Bis gels with low fraction of cross-linkers undergo discontinuous volume change at the specified temperature in water (Volume phase transition). Concerning the critical behavior of gels, NIPA hydro-gels with BIS (NIPA-BIS gels) are the most well studied gels. Y. Li et al.
(1) and K. D. Arai et al. (2) obtained the critical exponents of NIPA-BIS gel.
One of the most extreme gel with multi-functional crosslinker is a hydrogel crosslinked with small crystals of Laponite reported by K. Haraguchi et al.
(3); single Laponite crystal consists of about 2000 unit cells on average, and it has discotic form with diameter of about 30 nm and thickness of about 1.0 nm in aqueous solution. When the Laponite crystals are used as cross-linker, each crystal crosslinks a few thousand of chains due to the silanol groups on the surface of the crystal.
The NIPA-Laponite gels change the volume drastically by the temperature change and these gels are tough against external force. However, discrete volume change (volume phase transition) was not observed even at the very low fraction of crosslinker. This fact indicates that the number of the crosslinkers are very small compared to the BIS crosslinker, and the structure of the gels become very inhomogeneous.
Using the inhomogeneity as the keyword, we will discuss about the hysteresis loop and minor loops observed from NIPA-Lapomite gel.
References
(1) Y.Li and T.Tanaka, J.Chem.Phys.,90, 5161,(1989).
(2) K. D. Arai, A. Saito, K. Ito, Y. Uematsu, T. Ueno, Y. Fujii, and I.Nishio, Phys. Rev. E 87, 022603, (2013).
(3) K. Haraguchi, T. Takehisa, and S. Fan, Macromolecules, 35, 10162 (2002).

Figure 1
Physical Properties of Hydrogel Objects By 3D-Printing
Authors: Saito Azusa , Ota Takafumi , Yoshida Kazunari , Tase Taishi , Sato Kei , Tanaka Masanobu , Takamatsu Kyuichiro , Khosla Ajit , Kawakami Masaru , Furukawa Hidemitsu 
Published: February 2020

Since the gel has soft physical properties, it was difficult to process by conventional cutting or casting, but 3D gel printer was developed, and three-dimensional free modeling of the gel became possible. In this study, it is presented that the relationship between printing parameters of a 3D gel printer "Soft and Wet Intelligent Matter-Easy Realizer (SWIM-ER)" and mechanical properties of the fabricated gel objects by SWIM-ER. The printer can fabricate hydrogel objects by scanning of ultra-violet (UV) light irradiation (photopolymerization). Various hydrogels objects were printed with different scanning velocity of UV light. We measured the water content and mesh sizes of gel objects utilizing Scanning Microscopic Light Scattering (SMILS). Furthermore, we also printed the gel objects with multiple scan rates with constant UV light irradiation energy, and measured sizes of gel objects, and performed the compression test. It was observed that the physical properties of printed hydrogel objects are strongly related with 3D printing parameters due to difference in crosslinking density of polymer network.[1]
Ref.
[1] Takafumi Ota, et al., Mechanical Engineering Journal, 5, 1, 17-00538 (2018).
(Invited) Sweet and Sticky: Mucus Inspired Biomedical Hydrogels
Authors: Kramer Jessica , Schlirf Austin 
Published: February 2020

The human body has 200x greater mucosal epithelial surface area than skin, and produces roughly 10L of mucus daily. Mucus gel coatings on epithelial tissues function as hydrating, lubricating barriers and mediate absorption of nutrients, drugs, and pathogens and houses the majority of the microbiome. Despite essential biological roles, mucus remains poorly defined in terms of both composition and physical properties. Mucus is challenging to study because the major protein component is massive (0.5–20 MDa) and heterogeneous mucin glycoproteins. Currently, there are no methods to reproducibly access chemically defined mucins. This roadblock has rendered functional studies of one of nature’s most abundant and essential biomaterials incredibly challenging.
Mucus gels are thought to form via combination of physical entanglement and chemical bonds between individual mucin glycoproteins. We have prepared synthetic mucin glycopolypeptides via polymerization of glycosylated N-carboxyanhydrides (NCAs). We are exploring properties that drive assembly of individual mucin polymers into synthetic mucus gels. We are tuning gel properties (viscoelasticity, pore size, binding ability) by tuning the amino acid functional groups, cross-linker property/density, and glycosylation patterns. Access to tunable synthetic mucus will shed light on the properties of this essential biomaterial and open the door to study diverse epithelial processes such as mucosal transport of nutrients and drugs, as well as infection and immunity.
Gelation Behaviors of Amylosic Host-guest Supramolecular Networks Depending on Guest Polymers
Authors: Orio Saya , Yamamoto Kazuya , Kadokawa Jun-ichi 
Published: February 2020

Amylose, which is a helical polysaccharide, is known to form inclusion complexes with relatively low molecular weight guest compounds by hydrophobic interaction. However, little has been reported regarding the formation of inclusion complexes between amylose and polymeric compounds. The main difficulty in incorporating polymeric compounds into the amylose cavity is that the driving force for the binding is only caused by hydrophobic interactions. Amylose, therefore, does not have sufficient ability to include the long polymeric chains. The author has developed a new method of the polymerization system called “vine-twining polymerization” for the formation of well-defined polysaccharide supramolecules, that is, amylose–polymer inclusion complexes. The method was achieved by phosphorylase-catalyzed enzymatic polymerization of α-D-glucose 1-phosphate (G-1-P) monomer from malooligosaccharide primer to produce amylose, in the presence of hydrophobic synthetic guest polymers. The image of this polymerization system is the similar as the way that the vines of a plant grow twining around a rod.
In this study, we attempted to prepare supramolecular hydrogels composed of amylosic host-guest networks from different guest polymers by the vine-twining polymerization using maltooligosaccharide primer-grafted poly(g-glutamic acid) in the presence of the following guest polymers, polytetrahydrofuran (PTHF), poly(ε-caprolactone) (PCL), and poly(L-lactide) (PLLA). Consequently, we found that the reaction mixture using PTHF totally turned into hydrogel form, whereas the products using PCL and PLLA were aggregated in the reaction mixtures. It was speculated that the different behaviors were owing to stabilities of inclusion complexes as cross-linking points in the networks, depending on the guest polymers.
(Invited) Flexible Electronics in ITRI
Authors: Hu Je Ping 
Published: February 2020

Taiwan has strategically invested in flexible electronics for over 10 years. With Taiwan government’s support, ITRI has established the first flexible electronics pilot laboratory in Asia in 2007. The purpose is to facilitate the development of flexible electronics worldwide. During these years, many Taiwanese companies have entered the stage of mass production in flexible electronics, including E-paper, printed touch panels, printed RF-ID antenna, smart cards with displays, flexible pressure sensors, solar cells, etc. They have played key roles in the world.
In the recent years, there are three focuses in the flexible electronics pilot laboratory: 1) roll-to-roll for production revolution; 2) OLED lighting for sun-like color; 3) Bio-sensor platform. With over twenty leading companies, ITRI has developed cutting-edge flexible electronic technologies, such as roll-to-roll touch panels using 3um fine line printing based on 100um ultra-thin glass, free-shape ultra-thin substrate cutting technique with >500MPa bending strength, OLED light engines in pilot production scale, digital manufacture for industry. In this April, ITRI debuted the first high-end OLED lighting modules using full roll-to-roll process.
Flexibility and High-Rate Discharge Properties of Organic Radical Batteries with Gel-State Electrodes
Authors: Iwasa Shigeyuki 
Published: February 2020

Technology related to Internet of Things (IoT) and wearable devices has just begun to be actively developed. In that field, the demand for thinness and flexibility has increased in secondary batteries due to the structural compatibility of IoT or wearable devices such as vital sensors.
We have been developing organic radical batteries (ORBs) with cathodes consisting of nitroxyl radical polymers such as poly(2,2,6,6-tetramethylpiperidinyl-N-oxyl-4-yl methacrylate) (PTMA). Our previous work showed that ORBs with PTMA cathodes have high rate capabilities. PTMA is also known to be changed into a gel-like state due to the absorption of organic electrolytes. The PTMA gel in the electrodes is certain to be suitable for thin and flexible batteries because it is hardly damaged when it is repeatedly bent and unbent. However, the state of the PTMA cathodes in the battery has not been characterized, and the flexibility of ORBs with the PTMA cathodes has not been investigated so far.
The objective of this work is to clarify the state of the cross-linked PTMA cathodes in the battery and flexibility of the ORBs. We also report the electrode preparation method of cross-linked PTMA cathodes to obtain practical ORBs with both high rate discharge properties and excellent cyclability.
Cross-linked poly(2,2,6,6-tetramethylpiperidinyl-N-oxyl-4-yl methacrylate) (PTMA) gel used in organic radical batteries (ORBs) is characterized by rheological measurements, and the micro structure of gel-state cathodes is observed using low vacuum SEM. The storage elastic modulus of the cross-linked PTMA gel is under 10 kPa which is in the range of soft gel. It suggests that the PTMA cathodes are fairy flexible in the battery. The ORBs with the cathodes made from cross-linked PTMA/vapor grown carbon fiber (VGCF) composite show excellent discharge rate properties (20C/1C capacity 91%). The structure of needle-like VGCF penetrating PTMA particles in the composite results in excellent rate capabilities. In the PTMA gel cathode, the cross-link structure of the PTMA has the effect of maintaining homogeneous dispersion of VGCF, which gives improvement in cyclability. The capacity and resistance of the ORBs are maintained in the initial state after repetitive bending 250 times. We demonstrate that the gel state cross-linked PTMA is a promising electrode material for practical flexible batteries.