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Several divinyl ether and diepoxide monomers bearing an azobenzene moiety were synthesized and used to investigate the photoalignment of a ferroelectric liquid crystal (FLC) with no use of surface orientation layers. Azobenzene polymer networks, obtained by cationic polymerization of the monomers dissolved in the FLC host and exposed to linearly polarized irradiation, were found to be able to induce and stabilize a bulk alignment of FLC. Photoinduced reorientation of the FLC can also be achieved by changing the polarization of irradiation light, but in contrast with the use of chiral azobenzene poly(meth)acrylates, the results suggest a mechanism based on the formation of an anisotropic azobenzene polyether or polyepoxide network for the commanding effect on the FLC alignment.

A single linearly polarized irradiation was used to initiate cationic photopolymerization of an azobenzene-containing diepoxide monomer dissolved in a ferroelectric liquid crystal (FLC) and, at the same time, to induce fast trans-cis-trans photoisomerization cycles for the azobenzene chromophore which leads to a bulk alignment of the FLC in the absence of surface orientation layers. The spectral output of the light source is required to have separate UV and visible wavelengths, which allow for simultaneous photopolymerization of the monomer and photoalignment of the chromophore. Photopolymerization was allowed to take place in different phases of the FLC to reveal the effects on the FLC photoalignment; the interaction between the anisotropic azobenzene polymer network and the FLC host was also investigated using polarizing UV-Vis spectroscopy.

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