Preparation, photoisomerization, and microfabrication with two-photon polymerization of crosslinked azo-polymers.

ABSTRACT We report the preparation, photoisomerization properties, and three-dimensional (3D) microstructure fabrication with two-photon polymerization of crosslinked azo-polymers. A series of bi-acrylate-substituted azobenzene derivatives were designed and synthesized as the monomers and/or crosslinkers of the crosslinked azo-polymers. The doping concentration of the derivatives in pre-polymer resins was significantly increased due to the introduction of bulky tert-butyl and flexible alkyl chains. The double-exponential dynamics of trans-to- cis photoisomerization of the azo-polymers indicated the coexistence of different processes for the azobenzene moieties in the polymeric crosslinked networks. The crosslinked azo-polymers exhibited ideal 'on-off' switching performance in the highly reversible trans- cis- trans isomerization cycles. Furthermore, we prepared a photoresist containing the azobenzene derivative for 3D microstructure fabrication based on two-photon polymerization. A woodpile photonic crystal with a photonic bandgap at telecommunication wavelength region was successfully fabricated with the azobenzene-containing photoresist, which would open the way for the design and manufacturing of miniature optical communication devices. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2947-2956, 2013 [ABSTRACT FROM AUTHOR]