In this paper, we prepared Ag nanoparitcles with a diameter of 4～7 nm by reduction of AgNO₃ with NaBH₄ in the presence of PAMAM dendrimer as template. When the other conditions were identical, the size of particles increased with the increase of the molar ratio of Ag⁺ to dendrimer and when the generation of dendrimer was too higher, its role as template was more remarkable. The influence of pH of solution on the structure of nanoparticales was studied and the results showed that when pH was at 7.0±0.3, the silver nanoparticles which are well-stabilized with well-degree of dispersion and smaller in diameter, can be obtained. The silver nanoparticles were characterized by UV-visible absorption, transmission electron microscopy (TEM), automatic force microscope (AFM) and as well.

Key words: poly(amidoamine)(PAMAM)dendrimer, template, silver nanoparticle, dendrimer nanocomposite