Surface relief measurements in side-chain azobenzene polyesters with different substituents

Light-induced surface modification of a series of liquid-crystalline side-chain azobenzene polyesters which have the same main- and side-chain structure but eleven different substituents on the azobenzene is investigated. Using a transmission mask as well as single focused beams we show that the formation of the surface relief is dependent on the substituents. In both experiments irradiation with p-polarized light generates peaks for the CN, CF3, CH3 and F substituents, while fur a Cl substituent valleys art: observed. Also s-polarized light is found to produce surface deformations. An amorphous azobenzene polyester was included in the study for comparison. The results point to a mechanism of the surface relief phenomenon, in which the architecture of the polyesters plays a crucial role.