Effects of Temperature and Template Surface on Crystallization of Syndiotactic Polystyrene in Cylindrical Nanopores

Abstract

Crystallization of syndiotactic polystyrene (sPS) in anodized aluminum oxide (AAO) templates is investigated by FTIR. Nanopore surfaces of AAO templates are modified with n-hexyltrimethoxysilane to produce templates with alkyl surfaces, and effects of crystallization temperature and surface property of the template on the degree of crystallinity of sPS in nanopores of various sizes are studied. When isothermally crystallized at 245–260 °C, while the crystallinity in the bulk barely varies, in pristine and modified nanopores it increases substantially with degree of supercooling, which may be attributed to more surface-induced crystallization at lower temperatures. For all crystallization temperatures and pore sizes studied, sPS exhibits much lower crystallinity in the surface-modified templates, likely due to suppression of surface nucleation by the lower energy surfaces. This work reveals the significant role surface plays in polymer crystallization in nanotemplates and may aid the design and fabrication...