Chemical binding

About: Chemical binding is a research topic. Over the lifetime, 1822 publications have been published within this topic receiving 52516 citations.

Prostheses with associated growth factors

Abstract: A polypeptide growth factor is associated with a substrate to promote population of the substrate with endothelial cells. A prosthesis is formed with growth factor crosslinked to the substrate. Preferred polypeptide growth factors include VEGF. VEGF treated tissue can be populated with endothelial cells in vitro and/or in vivo. In an alternative approach, VEGF can be associated with the substrate by direct contact with a VEGF solution, application of the VEGF with an adhesive as a coating to the substrate, or chemical binding of the VEGF to the substrate with or without an intervening linker molecule. In one preferred approach, the growth factor is associated with the substrate by crosslinking under suitably mild conditions such that the growth factor is active following the crosslinking process.

Few-Layer Boron Nitride with Engineered Nitrogen Vacancies for Promoting Conversion of Polysulfide as a Cathode Matrix for Lithium-Sulfur Batteries.

Abstract: Lithium-sulfur (Li-S) batteries have become one of the most promising candidates as next-generation batteries, owing to their high specific capacity, low cost, and environmental benignity. Although many strategies have been proposed to restrain the shuttle of lithium polysulfides (LiPSs) through physical trapping and chemical binding, the sluggish kinetics of PS conversion still degrade the capacity, rate, and cycling performance of Li-S batteries. Herein, a novel kind of few-layer BN with engineered nitrogen vacancies (v-BN) has been developed as a cathode matrix for Li-S batteries. The positive vacancies in the BN nanosheets not only promote the immobilization and conversion of LiPSs, but also accelerate the lithium ion diffusion in cathode electrodes. Compared with pristine BN, the v-BN cathodes exhibit higher initial capacities from 775 mA h g-1 to 1262 mA h g-1 at 0.1 C and a high average coulombic efficiency of over 98 % during 150 cycles. Upon increasing the current density to 1 C, the cell still preserves a capacity of 406 mA h g-1 after 500 cycles, exhibiting a capacity decay of only 0.084 % per cycle. The new vacancy-engineered material provides a promising method for achieving excellent performance in Li-S batteries.

Perspective on “Zur Quantentheorie der Molekeln”

Abstract: The Born—Oppenheimer approximation, introduced in the 1927 paper “On the quantum theory of molecules”, provides the foundation for virtually all subsequent theoretical and computational studies of chemical binding and reactivity, as well as the justification for the universal “ball and stick” picture of molecules as atomic centers attached at fixed distances by electronic glue.

ALD of Ultrathin Ternary Oxide Electrocatalysts for Water Splitting

Abstract: Semiconducting oxides, particularly mixtures of different transition-metal oxides, are promising materials for oxygen evolution reaction (OER) catalysts. Assessment of these materials is often complicated by inadequate dispersion of the materials, charge transport limitations, and lack of surface area characterization. Thin films deposited by atomic layer deposition (ALD) present an excellent way to overcome these issues. Here, we present the first work using ALD to investigate ternary oxide electrocatalysts, specifically with the Ti–Mn ternary oxide system. Thin-film mixtures of between 1.4 and 2.8 nm in thickness are successfully synthesized by ALD and show a high degree of mixing. At compositions between ∼10 and 70% Mn:(Mn+Ti), there is a reduction in ALD growth rate relative to the growth rates of the binary constituents. Moreover, we observe a shift in the chemical binding energies of both Mn and Ti over this composition range. An elevation in the activity of Mn active sites for OER is observed with ...