Investigation of chitosan adsorption onto cotton fabric with atmospheric helium/oxygen plasma pre-treatment

In this study, the effects of helium or a helium/oxygen mixture atmospheric pressure plasma treatment on the adsorption of chitosan onto the cotton fabric were investigated. Fabrics were treated with plasma prior to a chitosan finishing process, whereby fabrics were surface coated using a pad/dry/cure method. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, surface energy analyser and contact angle measurements were used to investigate the changes on the cotton surface. Furthermore, antimicrobial activity of the cotton fabric was evaluated. The results showed that plasma pre-treatment enhanced the chitosan adsorption to the cotton surface through physical bonding and there was weak evidence of chemical bonding interactions. A combination of plasma and chitosan treatment did not show any significant differences on the antimicrobial properties compared to chitosan only treated fabric. Plasma treatment changed the fibres physically and enhanced the surface energy and thickness of chitosan distributed on the fibres.

Oxygen-doped boron nitride nanosheets with excellent performance in hydrogen storage

Hydrogen is considered one of the best energy sources. However, the lack of effective, stable, and safe storage materials has severely prevented its practical application. Strong effort has been made to try new nanostructured materials as new storage materials. In this study, oxygen-doped boron nitride (BN) nanosheets with 2-6 atomic layers, synthesized by a facile sol-gel method, show a storage capacity of 5.7wt% under 5MPa at room temperature, which is the highest hydrogen storage ever reported for any BN materials. Importantly, 89% of the stored hydrogen can be released when the hydrogen pressure is reduced to ambient conditions. Furthermore, the BN nanosheets exhibit an excellent storage cycling stability due to the stable two-dimensional nanostructure. The first principles calculations reveal that the high hydrogen storage mainly origins from the oxygen-doping of the BN nanosheets with increased adsorption energies of H2 on BN by 20-80% over pure BN sheets at the different coverage. © 2014 Elsevier Ltd.

Reduction of oxygen in a trialkoxy ammonium-based ionic liquid and the role of water

The oxygen reduction reaction in a novel trialkoxy ammonium-based ionic liquid, N-ethyl-2-(2-methoxyethoxy)-N,N-bis(2-(2-methoxyethoxy)ethyl)ethan-1-aminium bis(trifluoromethylsulfonyl)imide, [N2(20201)(20201)(20201)] [NTf2] has been studied on glassy carbon and gold electrodes, showing faster electrokinetics on glass carbon because of weaker adsorption of the IL. This has been demonstrated by theoretical calculations and electrochemical studies. In the neat IL, the oxygen is reduced to superoxide (O2 -) through a one electron process; however, better performance is attained in the presence of water (42 mol%), in terms of current density, and onset potential of the reduction process via a reversible 2-electron process. Furthermore, a remarkable increase in cyclic coulombic efficiency is observed for the wet IL (66% in comparison with the neat IL (24%), showing the practicality of a reversible O2/H2O2 system for energy storage.