Eutectic mesophase transitions and induced crystalline phase in mixtures of hexagonal columnar liquid crystal and mesogenic diacrylate
Eutectic behavior and the induced crystalline phase in mixtures of hexagonal columnar liquid crystal, 2, 3, 6, 7, 10, 11-hexakis-(pentyloxy) triphenylene (HPTP)/reactive mesogenic diacrylate monomer, 4-(3-acryloyloxypropyloxy)-benzoic acid 2-methyl-1, 4-phenylene ester (RM257) have been investigated both experimentally and theoretically. To determine the theoretical phase boundaries, we combined the free energy of Flory−Huggins free energy for liquid−liquid demixing, Maier−Saupe free energy of nematic ordering, and Chandrasekhar−Clark free energy of hexagonal ordering. The calculated phase diagram of the HPTP/RM257 blend is essentially of a eutectic type that consists of isotropic (I), nematic (N), and hexagonal columnar (Colh) regions, and nematic + isotropic (N+I), hexagonal columnar + isotropic (Colh+I), and hexagonal columnar + nematic (Colh+N) coexistence regions, bound by the liquidus and solidus lines. Of particular interest is the formation of an induced crystalline phase (Crin) in the intermediate compositions of the HPTP/RM257 mixtures, exhibiting Cr2 (RM257) + Crin in the RM257-rich and Crin + Cr1 (HPTP) in the HPTP-rich regions.
The Journal of Physical Chemistry B
Huang, Tsang-Min; Talroze, Raisa V.; and Kyu, Thein, "Eutectic mesophase transitions and induced crystalline phase in mixtures of hexagonal columnar liquid crystal and mesogenic diacrylate" (2010). Polymer Engineering Faculty Research. 977.