LIQUID CRYSTALS - POROUS GLASSES HETEROGENOUS SYSTEMS AS MATERIALS FOR INVESTIGATION OF INTERFACIAL PROPERTIES AND FINITE-SIZE EFFECTS

Porous silicate glass can be used as an ideal matrix to study the influence of temperature on the surface effects that occur at the interface between the glass and some other material. Since the structural characteristics of these matrices are nearly independent of the temperature, all observable effects when the temperature is changed can be attributed to the change in the physical properties of the second component (LC). Moreover, the dielectric permittivity of silica porous glass matrix is independent of the temperature and frequency for a wide range of frequencies. This fact and the practically negligible electrical conductivity of the matrix greatly simplify the interpretation of the results and make it possible to avoid a number of difficulties that have been encountered earlier in studies of dielectric properties of heterogeneous systems. It is shown that micro-heterogenous systems which have a liquid crystal as one of the components (the other one is the porous glass) are useful materials for investigations of interfacial and finite-size phenomena in LC. The results on the structure and temperature dependence of the interfacial layer of 5CB at interface between LC and wall of pore as well as dielectric studies of the influence of confinement on dynamics of molecular motion of LC in pores are discussed.