Alkali-cation-incorporated and functionalized iron oxide nanoparticles for methyl blue removal/decomposition.

Enhancing the rate of decomposition or removal of organic dye by designing novel nanostructures is a subject of intensive research aimed at improving waste-water treatment in the textile and pharmaceutical industries. Despite radical progress in this challenging area using iron-based nanostructures, enhancing stability and dye adsorption performance is highly desirable. In the present manuscript alkali cations are incorporated into iron oxide nanoparticles (IONPs) to tailor their structural and magnetic properties and to magnify methyl blue (MB) removal/decomposition capability. The process automatically functionalizes the IONPs without any additional steps. The plausible mechanisms proposed for IONPs incubated in alkali chloride and hydroxide solutions are based on structural investigation and correlated with the removal/adsorption capabilities. The MB adsorption kinetics of the incubated IONPs is elucidated by the pseudo second-order reaction model. Not only are the functional groups of -OH and -Cl attached to the surface of the NPs, the present investigation also reveals that the presence of alkali cations significantly influences the MB adsorption kinetics and correlates with the cation content and atomic polarizability.

Effect of reactive atmosphere of synthesis on properties of nano-ceria.

Ceria is an important rare-earth oxide with ever increasing applications. In nanocrystalline form, ceria exhibits novel and improved properties compared to its microcrystalline counterpart. The variation in the properties was observed to be a function of lowering particle size. This was also attributable to the presence and extent of Ce in 3+ state in ceria. Thermal decomposition of a thermally less stable cerium metal salt is an useful and simple method for the synthesis of nanocrystalline ceria. As atmosphere under which the decomposition occurs is expected to alter the Ce3+ content and thus the property, the present study is to investigate the effect of reactive atmosphere of decomposition vis-à-vis the particle size on the property of nanocrystalline ceria. Nanocrystalline ceria was synthesized by controlled thermal decomposition of cerium nitrate under four different atmospheres and the products were analyzed by X-Ray Diffraction, X-ray photoelectron spectroscopy and Laser Raman Spectroscopy. The observed property variation was found to be more dependent on the Ce3+ content thus the synthesis atmosphere rather than the particle size.

Solid phase synthesis of hydrophobic difficult sequence peptides on BDDMA-PS support.

This article illustrates the successful and efficient solid phase assembly of hydrophobic difficult sequence peptides following both t-Boc and Fmoc chemistry. The peptides were synthesized on an optimized 1,4-butanediol dimethacrylate-crosslinked polystyrene support (BDDMA-PS). Four difficult sequence test peptides, VAVAG, VIVIG, QVGQVELG and VQAAIDYING, were synthesized in relatively good yield and purity without any aggregation problems. The peptides were assembled on chloromethylated and 4-hydroxymethylphenoxymethyl (HMP) BDDMA-PS resins. The peptides were fabricated using Boc amino acid 1-hydroxybenzotriazolyl and Fmoc amino acid pentafluorophenyl active esters in coupling reactions. The peptides after synthesis were cleaved from the polymeric support by exposing the peptidyl resin to 90% trifluroacetic acid/5% thioanisole/5% EDT mixture. The HPLC and MALDI TOF MS studies of the peptides revealed the high homogeneity of the synthesized peptides. Chloromethylated resin having a functional group loading of 1.14 mmol Cl/g was used for the synthesis. The yield and homogeneity of these peptides synthesized using the new support were high when compared with the conventional DVB-PS resin.