Synthesis of Highly Dispersed, Block Copolymer-Grafted TiO2 Nanoparticles Within Neat Block Copolymer Films

The objective of the study is to formulate exclusive block copolymer (BCP) nanocomposites by dispersing bcp end-grafted nanoparticles (bcp-g-nps) of PMMA-b-PS-g-TiO2 within PS-b-PMMA matrix. PMMA-b-PS-g-TiO2 is synthesized using a grafting-to approach and characterized by XPS and TGA to establish that the copolymer chains were bonded to NPs. Good dispersion of bcp-g-nps in PMMA and PS-PMMA bcp films is observed, in contrast to poor dispersion in PS films. In PS-PMMA films, the compatible and identical bcp nature of the end-grafted polymer, and large NP size caused it to span across entire PS-PMMA domains. Poor and good dispersion in PS and PMMA matrices, respectively, can be rationalized by the fact that NPs interactions are driven by the PMMA at the outer corona of the bcp-g-nps. Developing bcp-g-nps as a strategic route to preparation of highly dispersed high permittivity NPs like titanium dioxide (TiO2) in bcp matrix can have important ramifications for energy storage devices. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 468-478