C60 fullerene inclusions in low-molecular-weight polystyrene-poly(dimethylsiloxane) diblock copolymers

We have synthesized low-molecular-weight diblock copolymers of polystyrene-block-poly(dimethylsiloxane) with total molecular weights < 12 kg/mol and PS volume fractions of similar to 0.2. We have investigated the phase behavior of the PS-PDMS in its pure state and with up to 10 wt% Of C-60 added. The C-60 was shown to selectively segregate into the PS phase only although its Solubility limit is similar to 1 wt%. Although the C-60 aggregates above 1 wt%. the cylindrical morphology observed in the pure copolymer bulk samples persists in the C-60-copolymer composites even up to 10 wt% C-60 loading. In thin films, the pure copolymer possesses a highly ordered morphology with grains hundreds of microns across. When C-60 is blended with the copolymer the high degree of order rapidly decreases due to increasing numbers of defects observed. (C) 2009 Elsevier Ltd. All rights reserved.