Visible light induced driving of crosslinked liquid-crystalline polymers by two-photon excitation

Abstract

We prepared interpenetrating polymer network (IPN) films containing azotolane as photochromic mesogens and D4ST (stilbene derivative) as two-photon chromophores. The IPN films showed macroscopic bending upon irradiation with visible-light laser pulses. Additionally, we investigated the energy transfer from D4ST to azotolane after two-photon excitation in solution. Upon irradiation with visible-light laser pulses, D4ST showed fluorescence, which was quenched by azotolane. Furthermore, azotolane in the D4ST solution showed the change in absorption spectra due to isomerization by irradiation with visible-light laser pulses. These results indicate that macroscopic deformation of the IPN films occurs by the energy transfer from D4ST to azotolane and subsequent trans-cis isomerization of azotolane.