One-pot low temperature synthesis of monodisperse silver nanoparticles.

A facile one-pot route for the synthesis of monodisperse Ag nanocrystals with a narrow size distribution is described. Uniform Ag nanoparticles with the size of around 12 nm were obtained by reduction of AgNO3 in the presence of oleylamine and polymer polyvinylpyrrolidone (PVP) at low temperature. It is found that temperature has a significant effect on the sizes and the size distributions of the nanoparticles. Because irregular Ag nanoparticles are produced easily due to Ostwald ripening or kinetic control at both high temperature and low temperature, respectively, uniform nanocrystals can be obtained at an appropriate temperature (70 degrees C).

[The IR spectra of complexes of fiber containing amidoxime groups with Fe(III), Co(II), Ni(II), Cd(II) and Hg(II)].

By the reaction Fe3+, Co2+, Ni2+, Cd2+ and Hg2+ with fiber containing amidoxime groups modified polyacrylonitrile fiber (AOCF), a series of coordinate complexes-AOCF-Fe(III), AOCF-Co(II), AOCF-Ni(II), AOCF-Cd(II) and AOCF-Hg(II) were prepared in acid medium. The fibers containing amidoxime groups with and without metal ions were taken for FTIR in the range of 4000-400 cm(-1). Their major bonds were assigned and compared. The results showed that in all complexes some bands (vC-N, vC=N and vN-O) were strengthened and a certain shift to higher wave number took place in the FTIR spectra with 4-21 cm(-1) shifts observed. The amidoxime groups and metal ions were bonding with coordinated bond.