Simulations of Morphology Evolution in Polymer Blends during Light Self-Trapping

Abstract

Simulations are presented for binary phase morphologies prepared via coupling the self-trapping properties of light with photopolymerization induced phase separation in blends of reactive monomer and inert linear chain polymer. The morphology forming process is simulated based on a spatially varying photopolymerization rate, dictated by self-trapped light, coupled with the Cahn–Hilliard equation that incorporates the free energy of polymer mixing, degree of polymerization, and polymer mobility. Binary phase morphologies form with a structure that spatially correlates to the profile of the self-trapped beam. Attaining this spatial correlation emerges through a balance between the competitive processes entailed in photopolymerization-induced decreases in diffusion mobility and the drive for the blend components to phase separate. The simulations demonstrate the ability for a self-trapped optical beam to direct binary phase morphology along its propagation path. Such studies are important for controlling the...