Thermal and Photochemical Control of Polyethylene imine having azobenzene side chan group

Abstract

Thermal and photochemical properties of polyethylene imine (PEI) having side chains with azo dye unit (4'-butylazobene derivative) were investigated. We synthesized two PEIs having different spacer length between the main chain and the azo dye unit. PEI104 having longer methylene spacer was found to form an out-of-plane structure by heating up to an isotropic phase and following cooling. The photochemical control of the molecular orientation of PEI104 between in-plane and the out-of-plane structures was achieved by a combination of thermal and photochemical processes.