ALIGNMENT OF LAMELLAR BLOCK-COPOLYMER MICROSTRUCTURE IN AN ELECTRIC-FIELD .2. MECHANISMS OF ALIGNMENT

Alignment of lamellar block copolymer microstructure in an electric fi eld was studied. Two mechanisms of alignment are considered: selective electric-field-induced disordering and alignment through movement of defects. The latter mechanism is supported by the findings that, in an aligned sample, defect structures exhibited a highly anisotropic arra ngement and were spatially clumped. An analysis:of field-induced force s on disclination lines and defect walls is presented. Also, defect in teractions are considered. Through the interplay between these forces, the alignment process, the kinetics of alignment, and clumping of def ects can be rationalized.