Lifetime distribution study on evolution of dimensionality in blend-like polymer films

Abstract

Abstract Fluorescence lifetime distributions were recovered from polymer films composed of poly(vinyl acetate) (PVAc) and poly(2-ethylhexyl methacrylate) (PEHMA) which were prepared by solvent casting. The PEHMA phase was labeled with a low concentration (0.7 mol%/PEHMA) of naphthalene groups. Exposure of the films to a pentane solution of 9-anthrylmethyl pivalate (AMP) transferred the AMP molecules exclusively to the PEHMA phase. The exponential series method (ESM) analysis was used to obtain lifetime distributions. The Laplace transformed Klafter-Blumen equation was employed to interpret lifetime distributions in terms of a fractal dimension. Swelling agents for PEHMA, such as hexadecane and PEHMA itself, were used to evaluate the dimensionality of the PEHMA phase. The apparent dimension of the PEHMA thread was explained with the idea of geometrical crossover in the interconnected network.