Organization of rigid wedge-flexible coil block copolymers into liquid crystalline assembly

The synthesis and characterization of wedge-coil block molecules with a poly(ethylene oxide) coil of 77 (1a), 91 (1b), 114 (1c), and 182 (1d) ethylene oxide units are described. The self-assembling behavior of these block polymers in the melt state was investigated by optical polarized microscopy, differential scanning calorimetry (DSC), X-ray scattering measurements, and transmission electron microscopy (TEM). Block polymers self-organize from 1-D lamellar to 2-D hexagonal columnar liquid crystalline phases as the length of the PEO chain increases. This result demonstrates that supramolecular nanostructures can be controlled in a rigid wedge-flexible coil block copolymer system through introduction of a long flexible coil.