Using light to control physical properties of polymers and surfaces with azobenzene chromophores

Azobenzene chromophores can be switched between two geometric isomers using visible light. This photoisomerization is rapid, reversible, and of high quantum yield, and the wavelengths effecting the transformation can be tuned synthetically with substituent groups to the chromphores. Upon isomerization, there can be significant changes to the optical, geometric, mechanical, and chemical properties of azobenzene molecules, and these photoswitchable properties can often be transferred to large host systems into which azobenzene is incorporated. This review describes polymers and surfaces that have been prepared recently that incorporate azobenzene groups, and some of the interesting physical and chemical properties that can be switched reversibly as a result.