Orientation of Microphase-Segregated Cylinders in Liquid Crystalline Diblock Copolymer by Magnetic Field

Abstract

This paper reports the first successful preparation of perfectly aligned cylindrical microdomains in liquid crystal (LC) diblock copolymer, polystyrene- block -poly-LC with a poly-LC composition of 84%, by application of a magnetic field. The prerequisite for their alignment is the exhibition of order-disorder transition of the microdomain structure. When the poly-LC segments transform from the isotropic phase to the nematic, well-defined microcylinders are concurrently formed from the weakly segregating state, and their alignment along the magnetic field is realized through the magnetic alignment of LC mesogens.