Unidirectional Bi-Continuous Morphology of Polymer Blends Undergoing Photopolymerization-Induced Phase Separation by Computer-Assisted Irradiation (CAI) Method

Phase separation of mixtures composed of a poly(ethyl acrylate), chemically labeled with Rhodamine-B [PEAR] dissolved in a methyl methacrylate [MMA] monomer, was induced by using a computer-irradiation (CM) method. This CM method enables us to control phase separation under temporal and spatial restrictions on the micrometer scale. By irradiation using light stripe patterns with three periods 108, 180 and 360 micrometers, we examined the possibility of anisotropic phase separation and also clarified the experimental conditions to obtain polymer films with uni-directional bi-continuous morphology. Effects of the three factors, photo-initiator concentration, molecular weight of the guest polymer PEAR and the cross-linker concentration, on the resulting morphology were examined to establish the relation between the light patterns and the resulting morphology under these particular irradiation conditions.