Orientation-Control of Liquid Crystal Molecules by Photochromism of Azobenzene

Langmuir-Blodgett films of amphiphilic azobenzene were prepared on a glass plate as a substrate of liquid crystal(LC)cell. Photochemical regulation of LC alignment was dependent on adsorption structure of azobenzene on a glass plate. When the amphiphilic LC molecules were sandwiched with two glass plates covered with hydrophobic surface of azobenzene, the transmittance change of the cell did not occur by UV and/or visible light irradiation. On the other hand, the relative transmittance of the cell in which the amphiphilic LC molecules were sandwiched with hydrophobic and hydrophilic surfaces of azobenzene film was changed reversibly by UV and visible light irradiation. Similar behavior was observed in the cell constructed with hydrophobic azobenzene surface/hydrophobic LC/hydrophobic azobenzene surface.