Effect of copolymer composition of controlled (N-vinylcaprolactam/N-vinylpyrrolidone) statistical copolymers on formation, stabilization, thermoresponsiveness and catalytic properties of gold nanoparticles

Abstract The insertion of an increasing amount of N-vinylpyrrolidone (VP) in statistical copolymers based on thermoresponsive poly(N-vinylcaprolactam) (PVCL) enables one to modulate the properties of the copolymer and those of the corresponding gold nanoparticles (AuNPs)-polymer hybrid materials. The incorporation of VP not only affects the growth of AuNPs synthesized in the presence of the polymers (in situ route), but also the properties (stabilization, optical, catalytic...) of preformed nanoparticles coated by these polymers. Hence, at a molar fraction of VP in copolymer less than 40%, it is possible to increase the transition temperature of the hybrid material and improve its catalytic properties compared to counterparts comprising PVP and PVCL homopolymers. The structural difference of the two monomers allows the best compromise between the hydration level and the interaction strength of the copolymer with the surface of gold particles for a chosen application.