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We study azimuthal gliding of the easy axis that occurs in nematic liquid crystals brought in contact with the photoaligned substrate ͑initially irradiated azo-dye film͒ under the action of reorienting UV light combined with in-plane electric field. For irradiation with the linearly polarized light, dynamics of easy axis reorientation is found to be faster as compared to the case of nonpolarized light. Another effect is that it slows down with the initial irradiation dose used to prepare the azo-dye film. This effect is interpreted by using the previously suggested phenomenological model. We present the theoretical results computed by solving the torque balance equations of the model that agree very well with the experimental data.

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A spontaneous bipolar-to-radial structural transition within nematic microdroplets is found with systematical changes of electrostatic properties of both liquid crystal mixtures and aqueous environments.

Electro-kinetic phenomena (EKP) arising under dc electric field in nanoporous polyethylene terephthalate (PET) films, filled with a nematic liquid crystal (NLC) 4-n-pentyl-4ʹ-cyanobiphenyl (5CB), were investigated for the first time. The volumetric flow rate was found to be directly proportional to the applied voltage U in the range of 0 . . . 30 V for both isotropic and nematic phases. Such type of dependences correspond to quasi-Newtonian behaviour of a liquid crystal (LC) with orientation strongly stabilised by surfaces. The value of zeta potential (about -12 mV) was estimated from the data, obtained in isotropic phase in the approximation of a 'plug' velocity profile. The possible role of electrically induced flows in previously reported electrooptical response of PET films filled with LC is discussed. The obtained results can be used for elaboration of optofluidic devices of a new type.

We experimentally study the reorientation dynamics of the nematic liquid crystal easy axis at photoaligned azo-dye films under the combined action of in-plane electric field and reorienting UV light linearly polarized at varying polarization azimuth, ϕp. In contrast to the case where the light polarization vector is parallel to the initial easy axis and ϕp = 0, at ϕp = 0, the pronounced purely photoinduced reorientation is observed outside the interelectrode gaps. In the regions between electrodes with non-zero electric field, it is found that the dynamics of reorientation slows down with ϕp and the sense of easy axis rotation is independent of the sign of ϕp.