Zinc oxide nanoparticles (NPs) with an average crystallite size of 22 nm and a bandgap energy of 3.26 eV have been obtained using neem (Azadirachta indica) leaf extract as a natural green stabilizing agent. Significant reduction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) quantity by ZnO NPs in dark has been found in the result of DPPH scavenging studies. This effect is explained by reductive action of the compounds from neem extract, immobilized on ZnO NPs, and it is an indicator of their antioxidant activity. It is shown that ZnO NPs demonstrate strong antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans.
The influence of the preparation method (impregnation of γ-Al2O3 vs. sol–gel method) on the physicochemical and catalytic properties of Ni-Mo-Al oxide systems in the CO2-mediated oxidative dehydrogenation of n-butane into C4 alkenes/dienes has been analyzed. It is shown that the catalyst obtained by a sol–gel method is characterized by a prevalence of the crystalline Al2(MoO4)3 phase in the composition and a lower acidity/basicity ratio. These features ensure higher selectivity and specific productivity toward the target buta-1,3-diene.
The effect of the polarity and volume fraction of organic solvents (n-heptane, isopropylacetate, ethylacetate, dichloromethane, and 1,2-dichloroethane) on the catalytic benzoylation of alanine, serine, and glutamic acid in a water–organic solvent two-phase system in the presence of pyridine N-oxide derivatives has been studied. It is found that the reaction occurs in a kinetic region, the effective rate constants increase with increasing solvent polarity. The possibility of replacing chlorine-containing solvents with ethyl acetate and isopropyl acetate was demonstrated, resulting in only a minor decrease in reaction rate ( 10
X-ray amorphous zirconium dioxide samples have been obtained by calcination of a mixture of zirconium oxychloride with sodium bicarbonate, sodium carbonate, or potassium oxalate. It is established that the efficiency of phosphate anion removal from Ringer’s solution by zirconium dioxide synthesized using sodium carbonate is higher (91.2
Micellization in a solution of sodium dodecyl sulfate (SDS) containing the antibiotic ofloxacin (OFX) in the presence of glucose or urea in the temperature range of 293-323 K has been studied by conductometry. It is shown that the critical micelle concentration (CMC) of SDS increases in the presence of OFX. The addition of urea increases the CMC in the SDS-OFX mixture, while in the presence of glucose the CMC decreases. The thermodynamic parameters of micellization, ∆ G_m^0 , ∆ H_m^0 , and ∆ S_m^0 , have been determined and it is proved that the SDS-OFX mixture undergoes spontaneous micellization both in pure water and in an aqueous solution of glucose or urea.
