Formation of thermoresponsive gold nanoparticle/PNIPAAm hybrids by surface-initiated, atom transfer radical polymerization in aqueous media

Abstract

We investigated the formation of thermoresponsive gold nanoparticle/poly(N-isopropylacrylamide) (AuNP/ PNIPAAm) core/shell hybrid structures by surface-initiated, atom transfer radical polymerization (SI-ATRP) in aqueous media and the effect of cross-linking on the thermoresponsiveness of the AuNP/PNIPAAm hybrids. The disulfide containing an ATRP initiator was attached onto AuNPs and the monomer, NIPAAm, was polymerized from the surface of AuNPs in the absence or presence of a cross-linker, ethylene diacrylate, in aqueous media at room temperature. The resulting brush-type and cross-linked AuNP/PNIPAAm hybrids were characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and variable temperature dynamic light scattering.