Silver nanoparticles formation within unsaturated polyester/styrene resins induced by UV irradiation and thermal treatment

Abstract

This article describes the formation of silver nanoparticles (NPs) within preformed unsaturated polyester/styrene resins in which the resulting color could be tuned by changing the silver load, time, and method used to grow the NPs. NP size and aggregation are responsible for the resulting sample color, and the samples present very good optical transparency. The silver ions were first added to the prepolymer that was crosslinked by free radical polymerization in the absence of light. NP formation was subsequently induced by submitting the transparent and colorless samples to heat or UV irradiation. Within the heated samples, isolated spherical particles ranging from 3 to 40 nm were observed. UV irradiation led to the formation of particle aggregates; however, as the exposure time was increased, silver NPs became well dispersed within the matrix within a particle diameter range of 9 to 24 nm. The particle formation is faster when induced by UV irradiation. Samples were also prepared by first dissolving rhodamine 6G in the resin. The emission bandwidth of samples prepared in this way showed a dependence on the silver particles amount and size. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers