Self-assembly behavior of POSS based ABA type amphiphilic tri-block copolymer prepared via ATRP

A series of ABA tri-block copolymers (TBCPs) of acryloisobutyl POSS (AibPOSS) and ten-butyl acrylate ((t)BA) with varying block length of poly(tert-butyl acrylate) (P(t)BA) was prepared via atom transfer radical polymerization (ATRP). P(t)BA block of these TBCPs, was selectively hydrolyzed to prepare poly(acryloisobutyl POSS)-block-poly (acrylic acid)-block-poly(acryloisobutyl POSS) (PAibPOSS-b-PAA-b-PAibPOSS). Interestingly, this hydrolyzed TBCP showed custard apple like, worm like and brush like morphologies in different block lengths of PAA (PAA(90), PAA(138) and PAA(166)) block. In this case, the TBCPs were dispersed in toluene followed by casting on the mica foil and subsequent evaporation, and then their morphologies were analyzed. Depending on the content of PAA, BCPs arranged themselves in spherical and cubical morphology over glass surface when cast with a mixed solvent (THF-water) (1: 4 vol ratio) followed by evaporation. To study the disparity in the particle size with the alternation of the PAA block length in solution, DLS analysis was carried out in THE-water mixture.