SEED Project: Influence of particles on Texture Evolution in Block Copolymer Blends

1. SEED Project: Influence of particles on Texture Evolution in Block Copolymer Blends Michael R. Bockstaller CMU MRSEC, Carnegie Mellon University, Pittsburgh, PA Block copolymer/nanoparticle (BCP/NP) composites have attracted interest because it is possible to control of orientation and location of particle fillers within the copolymer matrix and this offers unique opportunities for tuning the properties of hybrid materials. However, quiescent organized block copolymer microstructures are not macroscopically uniform but rather exhibit a polycrystalline structure with grain boundaries that disrupt the long-range periodicity. The aim of this study has been to elucidate the effect of particle additives on the structure of the grain boundary network in BCP/NP blends. It has been shown that addition of compatibilized particle additives results in the reduction of the average grain size in as-cast films by about 50% as well as a reduction of grain growth kinetics during thermal annealing. These findings provide the basis for future development of functional block copolymer blend materials for possible use as solid state electrolytes in lithium ion batteries or as bulk heterojunction materials. Electron micrographs depicting the formation of particle aggregates within high angle tilt (b, c, d, e) and twist (f) grain boundaries. Illustration of texture development of PS-PI and PI-PI/AuPS (1% w/v) during two days of thermal annealing at T = 120 deg C. DMR - 0520425