Synthesis of core-shell composite nanospheres PS/Ag and its characteristics

The core-shell PS/Ag composite nanospheres were synthesized via the method of fractional steps. Firstly, the highly monodisperse PS nanospheres were prepared by taking the emulsifier-free emulsion polymerization approach, and the carboxyl group of acrylic acid was used to modify their surfaces to be surrounded with negative charges. Secondly, [Ag(NH ₃) ₂] ⁺ was deposited on the modified surfaces of PS nanospheres and then was reduced with the SDS as the reducing agent in the water bath environment (80°C) so as to obtain the PS/Ag core-shell composite nanospheres. The particle size distribution, morphology and structure of the prepared core-shell PS/Ag composite nanospheres were chacacterized by using the dynamic light scattering and transmission election microscope. The influence of AA amount on the core-shell PS/Ag composite particle size and the coat of Ag shell thickness were investigated. It show that the Ag coating became more compact and thicker with the increase of AA amount. When AA came to 15%, the PS/Ag composite nanospheres with completely coated Ag were obtained.