Suppression of Membrane Degradation Accompanied with Increased Output Performance in Fuel Cells by Use of Silica-Containing Anode Catalyst Layers.

Polymer electrolyte membranes (PEMs) for fuel cells are chemically degraded by the attack of ·OH radicals generated from the decomposition of HO, which is predominantly produced at the Pt/C hydrogen anode. The incorporation of conventional radical scavengers into the PEM suffers from a decrease in the output performance. We, for the first time, demonstrate that the addition of hygroscopic silica nanoparticles (NPs) to the Pt/C anode catalyst layer provides a remarkably prolonged (ca.

Study of physical properties of a ferrimagnetic spinel CuMnO: spin dynamics, magnetocaloric effect and critical behavior.

The present work reports a detailed study of the spin dynamics, magnetocaloric effect and critical behaviour near the magnetic phase transition temperature, of a ferrimagnetic spinel CuMnO. The dynamic magnetic properties investigated using frequency-dependent ac magnetic susceptibility fitted using different phenomenological models such as Neel-Arrhenius, Vogel-Fulcher and power law, strongly indicate the presence of a cluster-glass-like behavior of CuMnO at 40 K. The magnetization data have revealed that our compound displays an occurrence of second-order paramagnetic (PM) to ferrimagnetic (FIM) phase transition at the Curie temperature = 80 K as the temperature decrease.

Facile Fabrication of a Highly Crystalline and Well-Interconnected Hematite Nanoparticle Photoanode for Efficient Visible-Light-Driven Water Oxidation.

Facile and scalable fabrication of α-FeO photoanodes using a precursor solution containing Fe ions and 1-ethylimidazole (EIm) in methanol was demonstrated to afford a rigidly adhered α-FeO film with a controllable thickness on a fluorine-doped tin oxide (FTO) substrate. EIm ligation to Fe ions in the precursor solution brought about high crystallinity of three-dimensionally well-interconnected nanoparticles of α-FeO upon sintering. This is responsible for the 13.

Synergistic Electrocatalytic Hydrogen Evolution in Ni/NiS Nanoparticles Wrapped in Multi-Heteroatom-Doped Reduced Graphene Oxide Nanosheets.

Hydrogen production is a key driver for sustainable and clean fuels used to generate electricity, which can be achieved through electrochemical splitting of water in alkaline solutions. However, the hydrogen evolution reaction (HER) is kinetically sluggish in alkaline media. Therefore, it has become imperative to develop inexpensive and highly efficient electrocatalysts that can replace the existing expensive and scarce noble-metal-based catalysts.

Flexible Methyl Cellulose/Polyaniline/Silver Composite Films with Enhanced Linear and Nonlinear Optical Properties.

In order to potentiate implementations in optical energy applications, flexible polymer composite films comprising methyl cellulose (MC), polyaniline (PANI) and silver nanoparticles (AgNPs) were successfully fabricated through a cast preparation method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating a successful incorporation of AgNPs into the MC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNPs into the MC/PANI blend.

Poly[2,2'-(4,4'-bipyridine)-5,5'-bibenzimidazole] functionalization of carbon black for improving the oxidation stability and oxygen reduction reaction of fuel cells.

The rapid oxidation of carbon black (CB) is a major drawback for its use as a catalyst support in polymer electrolyte fuel cells. Here, we synthesize poly[2,2'-(4,4'-bipyridine)-5,5'-bibenzimidazole] (BiPyPBI) as a conducting polymer and use it to functionalize the surface of CB and homogenously anchor platinum metal nanoparticles (Pt-NPs) on a CB surface. The as-prepared materials were confirmed by different spectroscopic techniques, including nuclear magnetic resonance spectroscopy, energy-dispersive X-ray, thermal gravimetric analysis, and scanning-transmittance microscopy.

Efficient tailoring of platinum nanoparticles supported on multiwalled carbon nanotubes for cancer therapy.

Therapeutically targeting cancer stem cells (CSCs), which play a role in tumor initiation and relapse, remains challenging. Novel-formulated platinum nanoparticles (Pt-NPs) supported on polybenzimidazole (PBI)-functionalized polymers and multiwalled carbon nanotubes (MWCNT) were prepared and their effect on CSCs was evaluated. Pt-NPs showed homogenous distribution on the surface of MWCNT/PBI composites, with very narrow particle size.

Tailoring Different Molecular Weight Phenylene-Polybenzimidazole Membranes with Remarkable Oxidative Stability and Conductive Properties for High-Temperature Polymer Electrolyte Fuel Cells.

Polybenzimidazole (ph-PBI) polymer was synthesized with different molecular weights (MWs) and casted into conductive films for use in high-temperature fuel cells (FCs). A comprehensive study on the influence of polymer MW on membrane cast efficiency, chemical stability, thermal behavior, tensile strength, conductivity, FC performance, and durability was reported. The synthesized materials were characterized by different techniques, including, nuclear magnetic resonance spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, impedance microscopy, and scanning electron microscopy.

Synthesis of a New Nitrate-Fertilizer Form with a Controlled Release Behavior via an Incorporation Technique into a Clay Material.

The current study shows an advanced synesthetic technique of a nitrate-fertilizer with a controlled release behavior into different soils (normal and acidic agriculture soils solutions) at different climate temperatures. The environmentally friendly and the biocompatible layered double hydroxide (LDH) clay material was used as a host to accommodate the nitrate anion into its interlayer gallery by applying a reconstruction-incorporation technique (the memory effect property of LDH that allows calcined LDH to memorize its original structure). The prepared materials were characterized by different spectroscopic techniques including; X-ray powder spectroscopy, IR, SEM, TEM, and TGA analyses.

Tailoring of a Potential Nanoformulated Form of Gibberellic Acid: Synthesis, Characterization, and Field Applications on Vegetation and Flowering.

Nanoformulation of agrochemicals has become a potential choice to improve the physicochemical properties, enhance the utilization efficiency, and reduce the side effects and ecotoxicity of many hazardous chemicals. Here, we tailored a new formulation platform for gibberellic acid (GA) using the layered double hydroxides (LDH) as a potential carrier. Typically, we synthesized, characterized, and potentially applied the newly nanoformulated form of GA on the quantity and quality properties of Dendranthema grandiflorum cultivar.

Improved Durability of Electrocatalyst Based on Coating of Carbon Black with Polybenzimidazole and their Application in Polymer Electrolyte Fuel Cells.

Improvement of durability of the electrocatalyst has been the key issue to be solved for the practical application of polymer electrolyte membrane fuel cells. One of the promising strategies to improve the durability is to enhance the oxidation stability of the carbon-supporting materials. In this report, we describe in detail the mechanism of the stability improvement of carbon blacks (CBs; Vulcan and Ketjen) by coating with polybenzimidazole (PBI).

A highly durable fuel cell electrocatalyst based on double-polymer-coated carbon nanotubes.

Driven by the demand for the commercialization of fuel cell (FC) technology, we describe the design and fabrication of a highly durable FC electrocatalyst based on double-polymer-coated carbon nanotubes for use in polymer electrolyte membrane fuel cells. The fabricated electrocatalyst is composed of Pt-deposited polybenzimidazole-coated carbon nanotubes, which are further coated with Nafion. By using this electrocatalyst, a high FC performance with a power density of 375 mW/cm(2) (at 70 ˚C, 50% relative humidity using air (cathode)/H2(anode)) was obtained, and a remarkable durability of 500,000 accelerated potential cycles was recorded with only a 5% loss of the initial FC potential and 20% loss of the maximum power density, which were far superior properties compared to those of the membrane electrode assembly prepared using carbon black in place of the carbon nanotubes.

Enhancement of platinum mass activity on the surface of polymer-wrapped carbon nanotube-based fuel cell electrocatalysts.

Cost reduction and improved durability are the two major targets for accelerating the commercialization of polymer electrolyte membrane fuel cells (PEFCs). To achieve these goals, the development of a novel method to fabricate platinum (Pt)-based electrocatalysts with a high mass activity, deposited on durable conductive support materials, is necessary. In this study, we describe a facile approach to grow homogeneously dispersed Pt nanoparticles (Pt) with a narrow diameter distribution in a highly controllable fashion on polymer-wrapped carbon nanotubes (CNTs).

Target delivery and controlled release of the chemopreventive drug sulindac by using an advanced layered double hydroxide nanomatrix formulation system.

Target delivery and controlled release of the chemopreventive drug sulindac that possesses low water solubility present a great challenge for its pharmaceutical industry. Here, we offered an advanced nanomatrix formulation system of sulindac based on layered double hydroxide materials. The X-ray analysis and infrared spectroscopy confirmed the incorporation of sulindac into the gallery of the layered double hydroxides.

Design of a multifunctional nanohybrid system of the phytohormone gibberellic acid using an inorganic layered double-hydroxide material.

To offer a multifunctional and applicable system of the high-value biotechnological phytohormone gibberellic acid (GA), a nanohybrid system of GA using the inorganic Mg-Al layered double-hydroxide material (LDH) was formulated. The ion-exchange technique of LDH was applied to synthesize the GA-LDH hybrid. The hybrid structure of GA-LDH was confirmed by different spectroscopic techniques.

Nanocomposite formulation system of lipid-regulating drugs based on layered double hydroxide: synthesis, characterization and drug release properties.

Purpose: To design a nanocomposite formulation system of lipid-regulating drugs with versatile approaches using layered double hydroxide (LDH) material.

Methods: The co-precipitation technique has been used to prepare the selected drugs [bezafibrate (BZF) and clofibric acid (CF)]-LDH nanocomposites. The nanocomposite materials (BZF-LDH and CF-LDH) were characterized by X-ray powder diffraction, infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy.

Unusually large hysteresis of temperature-responsive poly(N-ethyl-2-propionamidoacrylamide) studied by microcalorimetry and FT-IR.

We reported here the full characterization of the hysteresis of the phase transition behavior of an aqueous solution of poly(N-ethyl-2-propionamidoacrylamide) (PNEPA), which has a unique alpha,alpha-disubstituted structure, by using microcalorimetry and FT-IR. Phase transition temperatures near the thermodynamic equilibrium were determined by extrapolating the scanning rate of the microcalorimetry to zero. The calculated hysteresis from the phase transition temperature was unusually very large (approximately 8 degrees C).

Design of temperature-responsive polymers with enhanced hysteresis: alpha,alpha-disubstituted vinyl polymers.

Three temperature-responsive polymers which are alpha,alpha-disubstituted vinyl polymers having two amphiphilic groups (ethylamide or ethylester) per monomeric unit were designed. Two of these polymers showed unusually large hysteresis in their phase transition temperatures between a heating and a cooling process. This hysteresis resulted from the extremely slow kinetics of the dissolution process of the aggregated polymer chains in the cooling process due to intra- and interchain interactions including hydrogen bonding and hydrophobic interaction.

Nanocomposites of 2-arylpropionic acid drugs based on Mg-Al layered double hydroxide for dissolution enhancement.

Naproxen (NP) and flurpibrofen (FB) as non-steroidal anti-inflammatory drugs (NSAIDs) of 2-arylpropionic acid derivatives have been used as host organic drugs to be intercalated into layered double hydroxide (LDH) applying reconstruction and co-precipitation techniques. The obtained NP-LDH and FB-LDH nanocomposites were characterized by X-ray powder diffraction, infrared and thermogravimetric analyses. From drug loading, thermal analysis and X-ray measurements we can decide that coprecipitaion technique is better than reconstruction technique to obtain intercalated monophase nanocomposites.