[20a-W351-1~12] 12.3 Functional Materials and Novel Devices

[20a-W351-6] Analysis of liquid crystal structure due to water uptake in alkyl sulfonated polyimide monoaxial orientation film

〇Ryosuke Goto¹, Mitsuo Hara¹, Yuki Nagao², Syusaku Nagano³ (1.Grad. Sch. of Eng., Nagoya Univ., 2.JAIST, 3.Nagoya Univ. VBL)

Keywords:GI-SAXS,Sulfonated Polyimide,Lyotropic Liquid Crystal

Alkyl sulfonated aromatic polyimide (ASPI) was synthesized. The ASPI exhibited high proton conductivity (10-2 S cm-1) in thin films at the relative humidity of 95 %. Monoaxial oriented film of the ASPI was prepared by shear orientation from concentrated solutions. Polarized IR spectroscopy revealed that the polyimide main chain oriented parallel to the shearing direction with high dichroism. The concentration solutions of ASPI exhibited scattering profiles due to lamella phase by small angle x-ray scattering (SAXS) measurement. These results indicate that ASPIs exhibit lyotropic liquid crystal phase in the concentrated solutions. The liquid crystallinity could enhanced the shear orientation of polyimide main chain for the ASPI. Detailed Structural analysis for monoaxial ASPI films were performed by in-situ humid controlled grazing incidence small angle x-ray scattering (GI-SAXS) measurement. We observed highly orientational anisotropic structures in the monoaxial films by X-ray incidence set parallel and orthogonal to the shear direction. Moreover the highly ordered lamella structure was formed parallel to the substrate plane and the lamellar spacing was enhanced with humidity. We discuss the high proton conductive lyotropic structures of ASPI in thin film with humid condition from above data on detail.