Additive-Induced Elongation of Shape Anisotropic Block Copolymer Particles
발표자
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초록
내용
Shape-anisotropic block copolymer (BCP) particles have received great attention due to their spontaneous deformation induced by controlled phase separation in confined emulsion droplet. Here, we suggest a facile strategy to control the aspect ratio (AR) of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) prolate particles by incorporating bromoalkyl-based small molecule additives (BAS). The AR increased dramatically from 2.4 to 4.0 upon addition of BAS depending on the volume fraction of BAS. Furthermore, their morphological features were strongly influenced by the molecular structure of BAS (i.e., the number of Br and alkyl chain length of BAS). To understand the mechanism of elongation, domain spacing and morphological evolution kinetics were investigated. Domain spacing of lamellar increased from 63nm to 107nm by addition of BAS, and both PS and P2VP domains swelled symmetrically. Also, morphological evolution and partition behavior of domain was changed by presence of BAS.