Confinement of a nematogen in submicrometer cavities can produce substantial effects on the nematic-isotropic phase transition and on order and orientation of the nematic phase. We combine the methods of 13 C-and 1 H-NMR and broadband dielectric spectroscopy to probe liquid crystalline order and molecular mobility. We find that the dynamics of mesogenic molecules (5CB) in the free volume of nanoporous sol-gel glass (5nm pore diameter) is as fast as in the free bulk phase. In addition, a boundary layer of molecules with reduced mobility covers the pore walls. Isotropicnematic transition as well as crystallization of the confined nematogen are considerably suppressed. In order to extract the temperature dependence of the nematic order parameter from NMR data, a mathematical model is applied which describes the combined influences of orientational order and diffusional averaging in randomly oriented pores on NMR spectra of the nematogens.

This paper reports dielectric spectroscopic studies completed by electrochemical measurements in combination with DSC and PFG-NMR investigations to study the charge carrier transport in gel electrolytes, which were prepared by photoinitiated polymerization of oligo(ethylene glycol)23 dimethacrylate [(EG)23DMA] in the presence of oligo(ethylene glycol)11dimethyl ether [(EG)11DME] as plasticizer and LiCF3SO3. The resulting films show a glass transition at about −60 °C and the melting of the plasticizer around −12 °C. Below the glass transition two relaxation processes were observed by dielectric spectroscopy, which most likely are to be related to the γ relaxation of the EG groups and the β relaxation of the methacrylate groups. The high-temperature behavior of the dielectric response is dominated by the conductivity, which is weakly dependent on the frequency in this temperature range. The permittivity goes through a maximum at room temperature and decreases with further enhancement of the temperature in connection with an increase in ionic aggregation indicated by growing deviations from the Nernst−Einstein relationship. These deviations expressed as a Haven ratio are discussed as the contribution of bounded species that do not take part in the conductivity to the overall diffusivity, either by an enlarged content of these species, c b, or by an enhancement of their self-diffusivity, D b.

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