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Poly‐1‐vinyl‐1,2,4‐triazole (PVT)‐based materials with silver nanoparticles are promising antibacterial products. The metal nanoparticles with controllable sizes were obtained by radiation‐induced reduction of the dispersions of complexes of PVT with silver ions. Formation of the silver nanoparticles in aqueous suspensions irradiated at pH 6.0, 2.5, and 2.0 was studied using methods of UV–VIS spectroscopy and transmission electron microscopy. UV–VIS spectroscopy has detected a change in the efficiency of interaction between protonated or non‐protonated PVT units and the surface of silver nanoparticles. The interaction of macromolecules with the metal surface under different degrees of protonation of PVT functional groups afforded the nanoparticles with a narrow size distribution and an average size from 3 to 10 nm. An increase in the acidity also leads to a decrease in the ratio of the generation/growth of nanoparticles. The radiation approaches both provide the synthesis of the nanoparticles of controlled sizes and permits to obtain the nanocomposites containing no impurities of chemical reducing agents. The nanocomposites obtained exhibit high antibacterial activity against various bacterial strains, which depends on the size of silver nanoparticles. [ABSTRACT FROM AUTHOR]

Poly(styrene@N‐isopropylmethacrylamide‐methacrylic acid) [P (St‐NM)] microgels were prepared via seed facilitated emulsion polymerization process. In situ reduction of silver ions was carried out to generate Ag nanoparticles in the voids of shell region of polymer microgels. Synthesized P (St‐NM) and Ag‐P (St‐NM) particles were characterized by UV–Vis spectroscopy, transmission electron microscopy (TEM), Fourier‐transformed infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The stability of Ag nanoparticles within P (St‐NM) system over the wide range of pH and temperature is also a part of this study. Thus, prepared Ag‐P (St‐NM) was tested for its catalytic efficiency against reduction of K2Cr2O7 using formic acid (FA) as reductant. Factors affecting catalytic efficiency of Ag‐P (St‐NM) system towards transformation of Cr+6 to Cr+3 were investigated. Other toxic chemicals can also be reduced using same catalytic system. [ABSTRACT FROM AUTHOR]

Green tea extract having many phenolic hydroxyl and carbonyl functional groups in its molecular framework can be used in the modification of Fe3O4 nanoparticles. Moreover, the feasibility of complexation of polyphenols with silver ions in aqueous solution can improve the surface properties and capacity of the Fe3O4@green tea extract nanoparticles (Fe3O4@GTE NPs) for sorption and reduction of silver ions. Therefore, the novel Fe3O4@GTE NPs nano-sorbent has potential ability as both reducing and stabilizing agent for immobilization of silver nanoparticles to make a novel magnetic silver nanocatalyst (Fe3O4@GTE/Ag NPs). Inductively coupled plasma analysis, transmission and scanning electron microscopies, energy-dispersive X-ray and Fourier transform infrared spectroscopies, and vibrating sample magnetometry were used to characterize the catalyst. Fe3O4@GTE/Ag NPs shows high catalytic activity as a recyclable nanocatalyst for the reduction of 4-nitrophenol at room temperature. [ABSTRACT FROM AUTHOR]