Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 6 Articles
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Photocatalysis combined with membrane technology could offer an enormous potential for\npower generation in a renewable and sustainable way. Herein, we describe the one-step hydrogen\nand oxygen evolution through a photocatalytic membrane reactor. Experimental tests were carried\nout by means of a two-compartment cell in which a modified Nafion membrane separated the\noxygen and hydrogen evolution semi-cells, while iron ions permeating through the membrane\nacted as a redox mediator. Nanosized Au/TiO2 and Au/CeO2 were employed as suspended\nphotocatalysts for hydrogen and oxygen generation, respectively. The influence of initial Fe3+\nion concentration, ranging from 5 to 20 mM, was investigated, and the best results in terms of\nhydrogen and oxygen evolution were registered by working with 5 mM Fe3+. The positive effect of\ngold on the overall water splitting was confirmed by comparing the photocatalytic results obtained\nwith the modified/unmodified titania and ceria. Au-loading played a key role for controlling the\nphotocatalytic activity, and the optimal percentage for hydrogen and oxygen generation was 0.25 wt%.\nUnder irradiation with visible light, hydrogen and oxygen were produced in stoichiometric amounts.\nThe crucial role of the couple Fe3+/Fe2+ and of the membrane on the performance of the overall\nphotocatalytic system was found....
In this study, we blended PCL into poly(lactic acid) (PLA) and compatibilized these PLA/PCL blends by\nelectron-beam irradiation in the presence of a reactive agent to overcome drawbacks of PLA. To produce compatibilized blends,\nmixtures of the PLA/PCL/reactive agent were prepared using a twin-screw extruder and exposed to electron-beam radiation at room\ntemperature. Glycidyl methacrylate (GMA) was chosen as the reactive agent to achieve interfacial cross-copolymerization between\nPLA and PCL phases. Morphological, rheological, and mechanical properties and biodegradabilities of blends were investigated. The\nmorphological study showed significantly improved interfacial adhesion for compatibilized blends, and this was supported by FTIR\nanalysis and a rheological study. Impact strengths, thermal stabilities, and rheological properties of PLA/PCL blends were improved\nby compatibilization, and the biodegradabilities of compatibilized PLA/PCL blends were greater than that of pure PLA....
A comparative thermal decomposition kinetic investigation on Fe(III) complexes\nof a antipyrine Schiff base ligand, 1,2-Bis(imino-4â??-antipyrinyl)ethane\n(GA)), with varying counter anions viz....................
Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological\nactivities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-HIV, and\nanti-microbial activity. Recently, electrospraying has been successfully used to produce micro-or\nnano-sized particles for pharmaceutical use. In this work, polyvinylpyrrolidone (PVP) microspheres\ncontaining curcumin were prepared via electrospraying in order to improve the bioavailability of\npoorly-water-soluble curcumin. The influence of five processing parameters namely curcumin/PVP\nratio, tip to collector distance, and electric voltage on physic-chemical properties was investigated.\nThe characterization and aqueous solubility of particles were determined by using scanning electron\nmicroscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV-Vis spectrophotometer.\nThe result indicated that the spherical particles with particle size distribution of 164 to 730 nm\nobtained at a curcumin/PVP ratio of 1:30, a polymer solution concentration of 0.4%, electric voltage\nof 10 kV, and a tip-to-collector distance of 15 cm. Moreover, the dissolution of curcumin/PVP particle\ngenerated by electrospraying was higher than that of the original curcumin and pure curcumin\nparticles produced by electrospraying....
Transfer of graphene, grown by chemical vapor deposition (CVD), to a substrate of choice,\ntypically involves the deposition of a polymeric layer (for example, poly(methyl methacrylate)\n(PMMA), or polydimethylsiloxane, PDMS). These polymers are quite hard to remove without leaving\nsome residues behind. One method to improve the graphene transfer is to coat the graphene with a\nthin protective oxide layer, followed by the deposition of a very thin polymer layer on top of the oxide\nlayer (much thinner than the usual thickness), followed by a more aggressive polymeric removal\nmethod, thus leaving the graphene intact. At the same time, having an oxide layer on graphene may\nserve applications, such as channeled transistors or sensing devices. Here, we study the transfer\nof graphene with a protective thin oxide layer grown by atomic layer deposition (ALD).We follow\nthe transfer process from the graphene growth stage through oxide deposition until completion.\nWe report on the nucleation growth process of oxides on graphene, their resultant strain and their\noptical transmission....
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