This work is devoted to the synthesis and stabilization of nanosized Ag/SiO2 and Au/SiO2 disperse materials and investigation their morphology, optical and antimicrobial properties. First, Ag and Au nanoparticles (NPs...This work is devoted to the synthesis and stabilization of nanosized Ag/SiO2 and Au/SiO2 disperse materials and investigation their morphology, optical and antimicrobial properties. First, Ag and Au nanoparticles (NPs) were produced in colloids via chemical (Ag) or photochemical (Au) reduction of appropriate ions. To prevent the oxidation of Ag NPs in colloid solution, external binary stabilizing agents PVP and SDS were used. Then, Ag and Au NPs (0.01-0.05% wt) were adsorbed from their colloid solutions on high disperse silica surface (Ssp=260m2/g) and samples prepared were dried. Materials obtained were studied by UV-vis, XRD, and TEM methods. Ag and Au NPs adsorbed on silica demonstrated a fair crystallinity in XRD. The surface plasmon resonance (SPR) band positions inherent to Ag and Au NPs on silica surface as well as the intensities of optical spectra were stable during 7 month and more. Obtained Ag NPs in colloids and Ag/SiO2 composites demonstrated excellent antimicrobial activity against a series of the microorganisms (Escherichia coli, Staphylococcus aurous, and Candida albicans). Au/SiO2 samples did not reveal any bactericide properties relative to the test microorganisms grown. The mechanisms of Ag(Au) NPs interaction with silica surface were analyzed.展开更多
The β^+ decay of ^(31)Ar was investigated in an experiment at the GSI-FRS spectrometer.The ions of interest have been produced in the fragmentation of a ^(36)Ar beam at 880 Me V/nucleon and implanted in a time projec...The β^+ decay of ^(31)Ar was investigated in an experiment at the GSI-FRS spectrometer.The ions of interest have been produced in the fragmentation of a ^(36)Ar beam at 880 Me V/nucleon and implanted in a time projection chamber with optical readout. In addition to β-delayed one and two proton emission, for the first time the emission of β-delayed 3 protons has been observed. The branching ratio for this decay mode is found to be(0.07 ± 0.02)%.展开更多
文摘This work is devoted to the synthesis and stabilization of nanosized Ag/SiO2 and Au/SiO2 disperse materials and investigation their morphology, optical and antimicrobial properties. First, Ag and Au nanoparticles (NPs) were produced in colloids via chemical (Ag) or photochemical (Au) reduction of appropriate ions. To prevent the oxidation of Ag NPs in colloid solution, external binary stabilizing agents PVP and SDS were used. Then, Ag and Au NPs (0.01-0.05% wt) were adsorbed from their colloid solutions on high disperse silica surface (Ssp=260m2/g) and samples prepared were dried. Materials obtained were studied by UV-vis, XRD, and TEM methods. Ag and Au NPs adsorbed on silica demonstrated a fair crystallinity in XRD. The surface plasmon resonance (SPR) band positions inherent to Ag and Au NPs on silica surface as well as the intensities of optical spectra were stable during 7 month and more. Obtained Ag NPs in colloids and Ag/SiO2 composites demonstrated excellent antimicrobial activity against a series of the microorganisms (Escherichia coli, Staphylococcus aurous, and Candida albicans). Au/SiO2 samples did not reveal any bactericide properties relative to the test microorganisms grown. The mechanisms of Ag(Au) NPs interaction with silica surface were analyzed.
基金Polish National Science Center(UMO2011/01/B/ST2/01943)RFBR(14-02-00090)+1 种基金Polish Ministry of Science and Higher Education(0079/DIA/2014/43)Helmholtz International Center for FAIR
文摘The β^+ decay of ^(31)Ar was investigated in an experiment at the GSI-FRS spectrometer.The ions of interest have been produced in the fragmentation of a ^(36)Ar beam at 880 Me V/nucleon and implanted in a time projection chamber with optical readout. In addition to β-delayed one and two proton emission, for the first time the emission of β-delayed 3 protons has been observed. The branching ratio for this decay mode is found to be(0.07 ± 0.02)%.
