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 ∼0.2. We have investigated the phase behavior of the PS-PDMS in its pure state and with up to 10 wt% of C60 added. The C60 was shown to selectively segregate into the PS phase only although its solubility limit is ∼1 wt%. Although the C60 aggregates above 1 wt%, the cylindrical morphology observed in the pure copolymer bulk samples persists in the C60-copolymer composites even up to 10 wt% C60 loading. In thin films, the pure copolymer possesses a highly ordered morphology with grains hundreds of microns across. When C60 is blended with the copolymer the high degree of order rapidly decreases due to increasing numbers of defects observed.