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 infl uence of temperature on the surface effects that occur at the interfac e between the glass and some other material. Since the structural char acteristics of these matrices are nearly independent of the temperatur e, all observable effects when the temperature is changed can be attri buted to the change in the physical properties of the second component (LC). Moreover, the dielectric permittivity of silica porous glass ma trix is independent of the temperature and frequency for a wide range of frequencies. This fact and the practically negligible electrical co nductivity of the matrix greatly simplify the interpretation of the re sults and make it possible to avoid a number of difficulties that have been encountered earlier in studies of dielectric properties of heter ogeneous systems. It is shown that micro-heterogenous systems which ha ve a liquid crystal as one of the components (the other one is the por ous glass) are useful materials for investigations of interfacial and finite-size phenomena in LC. The results on the structure and temperat ure dependence of the interfacial layer of 5CB at interface between LC and wall of pore as well as dielectric studies of the influence of co nfinement on dynamics of molecular motion of LC in pores are discussed .