(43g) Ordering of Block Copolymer Surfactants Upon Blending with Non-Polymeric Additives

Block copolymers are attractive templates for nanostructured materials. The microphase separation of block copolymers and the resulting morphology are dictated by the segregation strength (XN) and the relative volume fractions of the different blocks. Pluronic block copolymer surfactants, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), are readily available at commercial scale but have low segregation strength and most do not microphase separate on their own at room temperature. In this work, it will be shown how well-ordered morphologies with domain spacings as low as 10 nm can be formed using Pluronic surfactants by blending with associating polymers and non-polymeric additives, including molecular glasses that can hydrogen bond to the PEO blocks. In comparison to polymeric additives, the non-polymeric additives offer additional structural, chemical and functional flexibility. For example, we discuss the blending of additives with chemically protected functional groups into Pluronic surfactants. By exposing to UV light, the additives can be deprotected to form groups that hydrogen bond to the PEO segments and induce disorder to order transition in the surfactant melts. Using such a photo-induced ordering strategy, arbitrary patterns of ordered nanostructures can be made in an otherwise disordered block copolymer film.