Synthesis and characterization of novel four-arm star PDMAEMA-stabilized colloidal silver nanoparticles

Spontaneous formation and efficient stabilization of colloidal silver nanoparticles were achieved in aqueous four-arm star poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) solution at ambient temperature in the absence of any other reducing agent. In this reaction, four-arm star PDMAEMA acted as both reducing and stabilizing agents for silver nanoparticles. More importantly, four-arm star PDMAEMA is a tertiary-amine-containing star homopolymer, which shows that the scope of the reducing and stabilizing agents for metal nanoparticles can be extended from the general homopolymers and the block copolymers to the water-soluble simple tertiary-amine-containing star homopolymers. Fourier transform infrared, UV-vis absorption spectroscopy, and transmission electron microscopy were used to characterize the synthetic silver nanoparticles. A plausible mechanism for the formation of silver nanoparticles was proposed in the presence of linear and star PDMAEMA homopolymers. Moreover, the size of the resultant silver nanoparticles can be easily tuned by changing the concentrations of AgNO₃.