Presentation Information
[23a-1BB-7]Thermal Diffusivity in Side-Chain Liquid Crystal Polymer Oriented Thin Films with Smectic Phases
〇Kanna Kobayashi1, Yuya Ishizaki1, Takahiro Seki2, Shusaku Nagano1 (1.Rikkyo Univ., 2.Nagoya Univ.)
Keywords:
Thermal diffusivity,Smectic phase,Liquid crystalline orientation
Liquid crystalline (LC) polymers have attracted as thermal management materials because of their highly ordered structures and large LC domains. Side-chain liquid crystalline (SCLC) polymers exhibiting smectic (Sm)C and E phases were synthesized by reversible addition-fragmentation chain transfer (RAFT) copolymerization of azobenzene and cyanobiphenyl monomers. We evaluated thermal diffusivity in the through-plane direction of the SCLC polymer thin films with the thickness ranging from 500 nm to 1.5 µm. The LC orientation was analyzed by grazing incidence X-ray scattering and p-polarized multiple-angle incidence resolution spectrometry. The thermal diffusivity in thin films was smaller than that in bulk. This indicates that the SCLC polymers with homeotropic orientation in thin films suppress the phonon diffusion in the through-plane direction. Moreover, we discussed the relation between the LC orientation and thermal diffusivity by controlling the LC orientation of the thin films using irradiation of visible nonlinear polarized light or annealing process in silicone oil.