A polysiloxane containing an amine hydrochloride in a side chain was polymerized via sol-gel condensation reaction of an alkoxysilane. This polymer was soluble in water. Organic-inorganic hybrid spincast films consisting of the water-soluble polysiloxane and lyotropic liquid crystals (e.g. long-chain alkylamine salt) absorbed or desorbed water molecules by a change in the relative humidity. Moreover, we found that the different lyotropic nanostructures in the hybrid films were reversibly induced depending on the relative humidity as revealed by in-situ grazing-incidence small-angle X-ray scattering measurements.
