Self-organization of OPV-PEG diblock copolymers in THF/water

Oligo(phenylenevinylene)‐poly(ethyleneglycol) (OPV‐PEG) diblock copolymers in tetrahydrofuran (THF) solution at concentrations of 5 to 25 g/l self‐assemble into rod‐like structures with a radius of about 80 Å, for an OPV‐PEG diblock copolymer comprising 13 PV and 45 EG monomers. These aggregates consist of a liquid crystalline OPV core and a PEG shell. Addition of about 10% water to the solution induces the formation of a phase of packed rods, as revealed by a sudden and dramatic transition of the scattering pattern. Further addition of water leads to swelling and at about 30% ultimately to disruption of the packed‐rod phase.