Effects of Addition of Large Particles on Lamellar Microphase-Separated Structure of Block Copolymer

[Original The in fl uence of added divinylbenzene ( DVB ) cross - linked particles, having a diameter of 3µm and 30µm, on the lamellar microphase - separated structure of styrene - 1,4 - rich - isoprene ( SI ) diblock copolymer is investigated. The DVB particles readily sedimented in toluene solution of SI due to low dispersibility, therefore the particles were localized in the lower part of the solvent - cast fi lms. The lamellar structure, formed in the process, exhibited preferential orientation along the direction parallel to the fi lm surface, and the domain spacing along the perpendicular direction was lower than in the parallel direction. The degree of preferential lamellar orientation was lowered by adding the DVB particles, leading to an increment in the domain spacing. Furthermore, the DVB particles with larger diameter gave lower domain spacing, though they produced a lower degree of lamellar orientation.