Influence of Nanoparticles on Glass Transition of Polymers

Abstract

Tunability of glass transition temperature of poly-methylmethacrylate has been achieved using homogeneously dispersed gold nanoparticles of different weight fraction within the polymer matrix. Remarkably, depression in glass transition temperature with respect to the neat polymer was observed for poly-methylmethacrylate (120 K and 15 K) by varying the weight fraction of the gold nanoparticles contrary to the conventional results in literature which shows elevation in Tg for attractive polymer-particle interaction, as is the case here. The magnitude of the shift in glass transition temperature is large for the higher of the two molecular weight of poly-methylmethacrylate studied here. Possible explanations of the observed behavior are provided, although more experiments are underway to unravel the intricacies of the observed phenomena.