Surfactant addition effects on dispersion and microdomain orientation in SBS triblock copolymer/alumina nanoparticle composites

Abstract The aim of this study was to investigate the effects of surfactant addition on the dispersion of 1–3 wt.% alumina nanoparticles on the self-assembled morphology of poly(styrene- b -butadiene- b -styrene) (SBS) linear triblock copolymer. The neat triblock copolymer microphase separated into PS cylinders self-assembled on a hexagonal array in the PB matrix, being the orientation of domains dependent on the annealing conditions. UV–vis and AFM analyses showed an improvement on dispersion of Al 2 O 3 nanoparticles into SBS matrix by adding dodecanethiol as organic surfactant, due to its miscibility with PS block. Interactions between surfactant-coated Al 2 O 3 nanoparticles with PS block were demonstrated by the variation on the glass transition temperature of this block. AFM analysis showed that the incorporation of surfactant-coated Al 2 O 3 nanoparticles in the SBS matrix have great influence on the orientation of microphase separated domains in SBS nanocomposites.