Thermal analysis and SANS characterisation of hybrid materials for biomedical applications

Silicate hybrid materials were prepared by the sol?Cgel process with the addition of x mass% of zirconium propoxide (x?=?0 and 1). The thermal behaviour as well as the influence of Zr addition was studied by thermal gravimetric analysis and differential thermal analysis. The microstructure evolution with temperature was investigated by X-ray diffraction and small-angle neutron scattering. It was found that the beginning of polymer degradation occurs at a higher temperature in the material prepared with addition of Zr than in the one prepared without. At the nanometric scale, the materials prepared without Zr show smooth interfaces, whereas those with Zr present a mass fractal structure. This structure is also observed in the material without Zr after thermal treatment at 200?°C. The results showed that bioactivity is favoured by mass fractal structures in comparison with one consisting of smooth surfaces.     

Flow injection spectrophotometric determination of vitamin E in pharmaceuticals,milk powder and blood serum using potassium ferricyanide-Fe(Ⅲ) detection system

<正>A simple and sensitive flow injection spectrophotometric method is reported for the determination of vitamin E using potassium ferricyanide-Fe(Ⅲ) detection system.In the presence of vitamin E,Fe(Ⅲ)/ferricyanide reduces.The in situ reduced ions are then reacted with unreduced portion of ferricyanide/Fe(Ⅲ) to make soluble Prussian blue,which is monitored at absorption wavelength of 735 nm.Linear calibration graph was obtained in the concentration range of 0.1-40μg mL~(-1).The relative standard deviations (n=4) were in the range of 1.1-3.6%,with limits of detection(3 s blank) of 0.04μg mL~(-1).The proposed method allowed 12 injections h~(-1).The method is applied to determine vitamin E in pharmaceuticals,infant milk and blood serum samples using hexane extraction with the recoveries in the range of 93±3 to 97.5±4%.The method is validated using certified reference materials SRM 968c for blood serum samples.     

Copper nanoparticles supported on 2‐methoxy‐1‐phenylethanone‐functionalized MCM‐41: An efficient and recyclable catalyst for one‐pot three‐component C–S coupling reaction of aryl halides with benzyl bromide and thiourea

An environmentally friendly copper‐based catalyst supported on 2‐methoxy‐1‐phenylethanone‐functionalized MCM‐41 was prepared and characterized by Fourier transform‐infrared, transmission electron microscopy, field emission‐scanning electron microscopy, X‐ray diffraction and inductively coupled plasma techniques. The catalyst was applied for the one‐pot three‐component C–S coupling reactions of aryl halides with benzyl bromide and thiourea under aerobic conditions to afford the corresponding coupled products in good yields in water. The catalyst could be recovered and recycled five times. These results prove 2‐methoxy‐1‐phenylethanone‐functionalized MCM‐41 supported Cu (II) complex was not leached during the reaction. Also it shows the correct heterogeneous nature of the catalyst.     

Synthesis of New Phosphonoamide and Phosphonocaprolactam Derivatives via the Diethyl Chlorophosphate‐Promoted Beckmann Rearrangement of γ‐Phosphonyloximes

Herein, we report an efficient and straightforward synthesis of new phosphonoamide and phosphonocaprolactam derivatives, via the Beckmann rearrangement of γ‐phosphonyloximes. The reaction proceeded smoothly in the presence of diethyl chlorophosphate as a promoter, to afford the title compounds in satisfactory yields. A mechanistic rationalization for this reaction is provided allowing for the prediction of its regiochemistry.     

Sorption studies of metal ions on napthol blue–black modified Amberlite IR-400 anion exchange resin: Separation and determination of metal ion contents of pharmaceutical preparation

Anion exchange resin Amberlite IR-400 has been modified with napthol blue–black. Effect of concentration, time, pH and temperature on the sorption of dye has been studied. The uptake sequence of various metal ions in a number of solvents has been determined. On the basis of distribution coefficients (K_d) in a number of solvent systems, some important binary separations of metal ions of analytical interest have been exploited. The practical applicability of the modified material has been demonstrated in the analysis of synthetic and commercially available antacid and antioxidant formulations namely digene and I-Vit.     

A comparative study of bismuth-based photocatalysts with titanium dioxide for perfluorooctanoic acid degradation

The fabricated bismuth-based photocatalysts presented an outstanding performance as compared to commercial TiO₂ (P25) for PFOA degradation under 254 nm UV light irradiation.     

Synthesis of corrected multi-wavelength spectrometers for atmospheric trace gases

The method for synthesis of corrected three-wavelengths spectrometers for trace gas components of atmo- sphere on the basis of development of mathematical model has been suggested. The classification table for possible structures of corrected spectrometers is considered. The synthesis allows to reveal some new variants for development of three-wavelength spectrometers for trace gas components of atmosphere. For experimental checkup of achieved theoretical results, a laboratory pattern of three-wavelength spectrome- ter is developed and tested.