By combining three key components in an AMOLED display pixel: the drive transistor, the storage capacitor, and the OLED stack into a single, gate voltage controlled, light-emitting element, the vertical organic light emitting transistor (VOLET) works together with low-cost, mature TFT technology to enable high performance AMOLED display panels that can be mass produced on fully depreciated LCD lines.

With very fast polymerization in mild reaction conditions and unique characteristic of double bonds in its synthesized polymer skeleton for further modification and functionalization, ring opening metathesis polymerization (ROMP) becomes one typical processing method to obtain anion exchange membrane (AEM) for fuel cells. In this paper, AEMs prepared by ROMP are reviewed. Polycyclooctene and polynorbornene AEMs with both good stability and high conductivity are achieved with different ion exchange groups such as quaternary ammonium, phosphorus and metal cations (such as bis(terpyridine)-ruthenium(II) and cobaltocenium). Polymer structure and ion channels are mainly constructed in the polymer skeleton to form the "ion channel" microphase-separated structure to improve its chemical stability and ionic conductivity. On the basis of selected ion exchange groups and optimized polymer skeleton, performances obtained in these ion exchange membranes (IEMs) and their corresponding fuel cell performances are summarized. These polycyclooctene and polynorbornene AEMs have excellent properties and promising performances in fuel cells. We believe that further exploration of this class of AEM may lead to practical applications.

Due to special non-metallic polar bond between the III group (with certain metallic properties) element boron (B) and the V group element nitrogen (N), boron nitride (BN) has unique physical and chemical properties such as strong high-temperature resistance, oxidation resistance, heat conduction, electrical insulation and neutron absorption. Its unique lamellar, reticular and tubular morphologies and physicochemical properties make it attractive in the fields of adsorption, catalysis, hydrogen storage, thermal conduction, insulation, dielectric substrate of electronic devices, radiation protection, polymer composites, medicine, etc. Therefore, the synthesis and properties of BN derived materials become the main research hotspots of low-dimensional nanomaterials. This paper reviews the synthetic methods, overall properties, and applications of BN nanostructures and nanocomposites. In addition, challenges and prospect of this kind of materials are discussed.

Vanadium redox flow battery (VRB), as the most promising large-scale electrical energy storage units, has attracted extensive attention. Amphoteric ion exchange membrane (AIEM), as the core part of VRB, separates electrolyte on both sides of electrolytic tank and conducts H+. The AIEM with cation and anion groups possesses excellent performances, such as high ion conductivity (σ), low vanadium ion permeability (PVn+), relative stability and low cost. However, the performance of AIEM directly depends on the chemical structure of polymers. In addition to ensuring foundational physical performance, ion selectivity of AIEM is significant since the crossover of vanadium ion with various valences may reduce the battery capacity. In this paper, AIEMs for VRB and their chemical structures as well as synthesis approaches to realize all kinds of high-performing AIEMs are reviewed. The current trend and future direction of prospective materials for the VRB separators are documented in detail as well.

Ionogels have aroused wide interests in the field of flexible electronics. The combination of solid-state networks and ionic liquids opens up thousands of possibilities for ionogels. The unique structures of ionogels endow them excellent mechanical properties, conductivity and thermal stability to approach the challenge of flexible electronic. A large number of new ionogels have been developed by different methods including the exchange of solution, polymeric ionic liquid and in-situ reactions in ionic liquids (gelation of low molecular weight gelators, self-assembly of block polymers, formation of double-network structure, ionogel nanocomposites and direct polymerization of polymerizable monomers). The aim of this review is to discuss different preparation methods of ionogels and the comparison of their advantages.

Graphene (Gr) and its derivatives (such as graphene oxide ( GO), reduced graphene oxide (RGO), nano-particles decorated graphene, etc.) reinforced metal matrix composites (MMC) with good structural mechanical properties and functional properties have wide applications in aerospace, automotive, electronics and military fields. However, some problems exist in preparing high performance MMC including poor wettability between Gr-type fillers and metal matrix, and weak interfacial bonding strength. Efficient methods for preparing Gr-related nanomaterials filling metal matrix parts with high performance, especially for complex parts still need be further developed. The engineering application field of Gr MMC needs to be further expanded. In this paper, methods to prepare high performance MMC including surface modification of Gr and its derivatives, properties and applications of these reinforced MMC were reviewed with detailed examples. The main challenges were analyzed and the development trend of Gr-type types reinforced MMC was discussed. (C) 2020 Elsevier Ltd. All rights reserved.

With increasingly stringent environmental regulations, desulfurization for gasoline oil production has become an important issue. Nowadays, desulfurization technologies have become an integral part of environmental catalysis studies. It is also important for processing of fuel for fuel-cells, which has a strict requirement for sulfur content for internal combustion engines. In this study, we focused on the preparation and characterization of magnesium hydroxide/aluminum supported NiO, ZnO, ZrO2, NiO-ZnO, NiO-ZrO2, adsorbents for the adsorptive desulfurization of liquid fuels. These hydrotalcite adsorbents were prepared by co-precipitation method and used for adsorption of thiophene (in n-pentane, as model fuel) and dibenzothiophene at ambient temperature and pressure. The physicochemical behaviors of the fresh adsorbents such as structure, composition, and bonding modes were determined using X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-Ray analysis (EDAX), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The sulfur concentration in the mixture (thiophene and n-pentane) was measured by UV-Vis spectrophotometry. The percentages of thiophene removal and the adsorption capacity (mg of sulfur per g of adsorbent) of the five adsorbents were compared. The adsorption performance confirmed that NiO-ZrO2 and NiO-ZnO adsorbents are more efficient in removing thiophene/dibenzothiophene than that of three other adsorbents. The qualitative studies using XPS confirmed the efficient adsorption nature of modified hydrotalcite adsorbents on dibenzothiophene.

Polymer composites play a significant role in developing flame retardants to prevent fire accidents. The current work aims at investigating the flame retardancy of vinyl ester resins (VER) reinforced with nanotitania (nano-TiO2) nanofiller. The surface functionality of nano-TiO2 was modified by adding Si and N2 to improve its flame retardancy. The chemical structure and thermal stability of nanocomposites were studied using Fourier-transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA). Peaks of Si and N2 in the modified TiO2-VER nanocomposite and weight loss of the modified composite confirmed the addition of Si and N2. The tensile strength results have shown that modified TiO2-VER nanocomposites didn’t make any significant impact on the tensile strength in comparison with pure VER. The flammability and thermal stability behaviors of these nanocomposites are evaluated using microscale combustion calorimetry (MCC). At high percent loading of nanofiller, the normalized heat release capacity (HRC) of modified TiO2-VER nanocomposites was decreased by 27.7%, whereas the HRC of unmodified TiO2-VER nanocomposites was only reduced by 9.8%. Also, the normalized total heat release of modified nanofiller based PNC was found to be 21.4%, whereas the unmodified PNC was 12.4%.

Small specific surface area as well as fast recombination rate of photoelectron–hole pairs deteriorated the photocatalytic performances of carbonitride carbon (g-C3N4) in solving environmental pollution and energy crises. In this study, cuprous oxide (Cu2O) nanocubes grew on the g-C3N4 porous nanosheet to form a n–p nanoheterostructure. This unique structure of the prepared g-C3N4/Cu2O photocatalyst resulted in the photogenerated electron–hole pairs having enhanced separation rates. Under visible light irradiation, heterojunction degradation ability of methyl orange was significantly increased and its enhanced mechanism was systematically studied.

Starch has received much attention due to the advantages, such as low cost, wide availability, and excellent compostability without toxic residues. However, starch-based materials are known with limitations related to weak mechanical properties and poor long-term stability, which could be overcome by incorporation with carbonaceous nanofillers. Thus, nanobiocomposites, namely dispersion of nano-sized fillers into a starch-biopolymer matrix, is one of the most promising technological advances. The starch-based carbonaceous nanofillers not only improve the poor mechanical properties of starch, but also change the performance of carbonaceous nanofillers solubility in water. This paper reviews the state-of-theart in the field of starch-based carbonaceous nanofillers. Two types of carbonaceous nanofillers including carbon nanotubes and graphene that have been used with starch are discussed. The main properties and applications of starch-based carbonaceous nanofillers are also discussed.

Novel waterborne acrylic resin modified by cellulose acetate butyrate was successfully synthesized by a homogeneous solution polymerization with 2-butoxy ethanol, cellulose acetate butyrate and acrylic monomers as raw materials, N, N -dimethyl ethanolamine as neutralization and gamma-aminopropyltriethoxysilane (KH-550) as curing agent. The influences of the cellulose acetate butyrate and curing agent content on the properties of the waterborne acrylic resin were investigated. As a curing agent, KH-550 not only improved the cross-linking density of the resin effectively, but also bonded to the substrate to form a molecular layer of silane. Cellulose acetate butyrate and KH-550 were found to reduce the curing temperature of the resin. The tensile strength of the coating added with the curing agent (5.89 MPa) was significantly improved compared to that of cellulose acetate butyrate modified resin (1.49 MPa). This kind of environment-friendly waterborne acrylic resin has a strong potential application in wood coatings, automobile coatings and other fields.

Lignin is a widely used adsorbent for removing heavy metal ions from water. Lignin can be extracted from black liquor and its inert surface properties limit its adsorption performance. In this paper, a new type of modified lignin adsorbent doped with Cu/N was prepared by the reaction of lignin with triethylenetetramine (TETA) and CuCl2. The adsorption capacities of the Cu/N-doped lignin (Cu/N-Lignin) adsorbents, N-doped lignin (N-Lignin) adsorbents and undoped lignin (U-Lignin) on three anions (As (V), Cl- and Cr (VI)) were systematically studied. In the solution with these three mixed ions, the removal rate of the Cu/N-Lignin adsorbents on As (V), Cl- and Cr (VI) was 86.4-4%, 0% and 39.48%. The adsorption capacity of Cu/N-Lignin to As(V) was 253.5 mg/g. Under the same adsorption conditions, the selectivity of the Cu/N-Lignin adsorbents to anions was Cl- <Cr(VI)<As(V), and it also had a strong reusage capacity. This study shows a great potential of using lignin in wastewater treatment and selective adsorption of oxyanions. (C) 2020 Elsevier B.V. All rights reserved.

It was well established that microwave radiation was utilized initially to enhance the electrical conductivity of polymer nanocomposites (PNCs) by introducing carbon nanotubes (CNTs) without using any solvent.High electrical conductivity was obtained in polypropylene (PP) nanocomposites with low CNTs loading levels.Under an inert gas protection, the CNTs were heated through the transformation of electromagnetic energy into mechanical vibrations.The surface of PP was easily molten by the heat generated by CNTs, then a well-formed CNTs network was built under proper microwave treatment period and subsequent hot pressing.CNTs loading levels and processing temperatures played an important role in the crystal structure, crystalline fraction and crystallization temperature of both nest PP and its PP/CNT PNCs.Moreover, the pressing temperature and CNT loading levels had an obvious effect on the electrical conductivity, which were the main factors on network formation.Electron transport with a three-dimensional route was observed from the study of the variable range hopping (VRH) mechanistic.The unique negative magnetoresistance (MR) phenomenon was shown in the PNCs and theoretically discussed by the forward interference model.The calculated optical band-gap of PNCs decreased with increasing the CNT loading.Other properties have been also well tested and analyzed.

Cu2Nb34O87 with an inverse opal morphology is fabricated, showing highly-ordered macropores with sizes of ∼170 nm and walls with thicknesses of 20-30 nm. This first-reported Cu2Nb34O87 nanomaterial exhibits good Li+-storage properties, including a large capacity, safe operating potential, large initial coulombic efficiency, high rate performance and good cycling stability.

The demand for processing recycled acrylonitrile-butadiene-styrene copolymer plastics (R-ABS) grows fast. Herein, epoxidized styrene-butadiene-styrene (ESBS) with reactive groups including polybutadiene (PB) phase, epoxidized polybutadiene (EPB) phase and polystyrene phase is prepared by modifying SBS with an in situ peroxyformic acid method. Both chain extension and phase interface reparation of R-ABS are successfully reported by simple melt blending. Compared with R-ABS, when ESBS content is 15 wt%, the average molecular weight (M-w) of the ESBS/R-ABS is increased from 118.01 to 612.51 kDa. The particle size of the dispersed phase is decreased obviously. The compatibility between these two phases became better. The average notch impact strength of R-ABS is 5.72 kJ m(-2). When the ESBS content is 15 wt%, the average notch impact strength of ESBS/R-ABS reaches 13.90 kJ m(-2), which is increased by 143% compared with that of R-ABS. The notch impact strength of ESBS/R-ABS is close to that of virgin ABS. The reported high-value usage of R-ABS has a great potential for industrial-scale applications.

Polymer composites play a significant role in developing flame retardants to prevent fire accidents.The current work aims at investigating the flame retardancy of vinyl ester resins (VER) reinforced with nanotitania (nano-TiO 2 ) nanofiller.The surface functionality of nano-TiO 2 was modified by adding Si and N 2 to improve its flame retardancy.The chemical structure and thermal stability of nanocomposites were studied using Fourier-transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA).Peaks of Si and N 2 in the modified TiO 2 -VER nanocomposite and weight loss of the modified composite confirmed the addition of Si and N 2 .The tensile strength results have shown that modified TiO 2 -VER nanocomposites didn't make any significant impact on the tensile strength in comparison with pure VER.The flammability and thermal stability behaviors of these nanocomposites are evaluated using microscale combustion calorimetry (MCC).At high percent loading of nanofiller, the normalized heat release capacity (HRC) of modified TiO 2 -VER nanocomposites was decreased by 27.7%, whereas the HRC of unmodified TiO 2 -VER nanocomposites was only reduced by 9.8%.Also, the normalized total heat release of modified nanofiller based PNC was found to be 21.4%, whereas the unmodified PNC was 12.4%.

Exposure of single-walled carbon nanotubes (CNTs), as well as other lower cost layered graphitic carbons (LGCs), to acidic intercalants, in combination with low voltage electrochemical cycling, induces in these materials hydrogen evolution activity that initiates at near zero overpotential and is on par with that of platinum catalysts.1 These results encouraged the further development and testing of the CNT catalyst in a PEM water splitting electrolyzer prototype. Once activated, the CNT cathode demonstrated 1 A/cm2 of HER current at 1.64 V, comparable to a similarly tested commercial Pt-loaded cathode. While carbon nanotubes are not intrinsically scarce, the single wall nanotubes used in these electrode tests remain relatively expensive. Commercial significance would benefit from a demonstration of comparable performance from activated lower cost layered graphitic carbons in a PEM electrolyzer prototype. The following LGC materials, having a combination of high electrical conductivity, large pore volumes, and high specific surface areas, were tested in terms of their ability to achieve low HER overpotential during the activation process: microcrystalline graphitic particles, Vulcan XC-72 carbon, highly graphitized stacked-cup tubular carbon nanofibers (CNFs), and carbon needle felt. CNF electrodes demonstrated slightly higher mass basis activity than that of the other tested LGCs in acid electrolyte in a standard three-terminal electrochemical cell. Here we report excellent performance from activated CNF cathodes, prepared by a scalable spray-coating method, in our PEM electrolyzer prototype (IrRuOx as anode catalyst). As anticipated, a control MEA, based on the non-activated CNF cathode and tested in PEM electrolyzer under identical conditions, showed poor performance, indicating a low electrocatalytic HER activity of the electrode. The activated CNF cathode-based PEM electrolyzer achieved 1 A/cm2 at 1.78 V, while a control commercial MEA with Pt-loaded cathode/IrRuOx anode (a high Pt catalyst loading of 3 mg/cm2 cathode, Fuel Cells Etc) tested in the same PEM electrolyzer cell demonstrated 1 A/cm2 at 1.7 V. Acknowledgements. This work is supported by Amazon through ECS Amazon Catalyst Program. References: R. K. Das, Y. Wang, S. V. Vasilyeva, E. Donoghue, I. Pucher, G. Kamenov, H.-P. Cheng, A. G. Rinzler, ACS Nano, 2014, 8 (8), 8447–8456.

Anticipated increases in worldwide energy consumption, the reality of ultimately limited hydrocarbon fuels, as well as their contribution to global warming, have all encouraged the development and commercialization of renewable, carbon neutral, energy technologies. An issue for renewable energy sources like solar, wind and wave energy is their intermittency. An efficient means to overcome this intermittency is to build excess capacity into the generating plants and to use that excess capacity to produce high energy density hydrogen fuel via water electrolysis for on demand reconversion to electrical energy in fuel cells. A major impediment to this solution is that commercial water splitting electrolyzers use scarce and costly precious metal catalysts which make such an energy storage/recovery scheme prohibitively expensive. Alternative, earth-abundant, non-precious metal catalysts are highly desired. We recently demonstrated that purified single wall carbon nanotubes (SWNT), and select layered graphitic materials, activated by a simple electrochemical process, provide an exceptional non-precious metal electrocatalyst for the hydrogen evolution and the hydrogen oxidation reactions in both acidic and near neutral pH. [1] Here we validate this result for hydrogen evolution in a single-cell PEM electrolyzer. The MEAs studied used Nafion 115 and an IrRuOx anode. Three distinct cathodes were tested: 1) commercially available Pt loaded (3.0 mg/cm2) Vulcan X-72 carbon (for a point of comparison); 2) non-activated SWNTs; and 3) activated SWNTs. In all cases I-V measurements were performed at 80oC. The commercial Pt loaded MEA exhibited the high gas production rates expected from engineered Pt, converting 1.0 A/cm2 at 1.67 V. The non-activated SWNTs yielded very low gas production rates requiring 1.89 V for a current of only 0.040 A/cm2. The activated SWNTs demonstrated a performance completely comparable, at all potentials, with that of the commercial Pt electrode (see Figure), attaining 1.0 A/cm2 at 1.64 V. Ninety hours of operation showed no degradation in the cathode performance. It has been estimated that a 50% reduction in the cathode Pt used would result in a 15% electrolyzer cost reduction. [2] Our entirely Pt–free electrode using only earth abundant carbon could nearly double that cost saving. Acknowledgements. This work was supported by Nanoholdings, LLC. References: [1] R. K. Das, Y. Wang, S. V. Vasilyeva, E. Donoghue, I. Pucher, G. Kamenov, H.-P. Cheng, A. G. Rinzler, ACS Nano, 8 (8), 8447–8456 (2014) [2] K. E. Ayers, E. B. Anderson, C. B. Capuano, B. D. Carter, L. T. Dalton, G. Hanlon, J. Manco, and M. Niedzwiecki, ECS Transactions, 33 (1), 3-15 (2010) Figure 1