Disclination network morphologies in blue phase III

We prepared some blue phase (BP) materials with different concentrations of reactive monomers. They exhibited a cubic blue phase (cubic BP) or blue phase III (BPIII). We obtained their polymer-stabilised cubic BP and BPIII liquid crystals using photo-polymerisation. The temperature ranges of both BPs widened with increasing monomer concentration. After removing the low-molecular-weight materials, we observed the remaining polymer networks using field-emission scanning electron microscopy (SEM). We investigated the relationship between the polymer-stabilised BP (PS-BP) temperature range and polymer network morphology. The polymer network derived from the non-stabilised PS-BPIII exhibited µm-sized pores. Increasing the monomer concentration, the BPIII temperature range widened from 13 K to more than 49 K and the pore size dramatically decreased from several µm to about 100 nm. On the other hand, periodic nanoporous structures were partially observed even for the PS-cubic BP. The nanoporous structures were spread to the whole area for the PS-cubic BP with a wide BP temperature range. Furthermore, we discuss how the polymer network stabilises BPIII.