Phase Morphology and Crystal Orientation Changes in Nano-Confined Lamellae of PEO-b-PS Block Copolymer

摘要

Crystallization temperature (T_C)-dependent crystal orientations within nano-confined lamellae have been studied in poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymers. The PEO-block crystallization takes place in a one-dimensionally (1D) confined glassy PS environment. Using combined two-dimensional (2D) Small Angle X-ray Scattering (SAXS) and Wide Angle X-ray Scattering (WAXS) techniques, the crystal orientation (the c-axis of the PEO crystals) is found to change from random to parallel, then to inclined and finally to perpendicular to the lamellar surface with the Tc increasing. The effect of the confined size on the T_C-dependent crystal orientations has been considered.