Dynamics of molecular motion of nematic liquid crystal confined in cylindrical pores

Broadband dielectric spectroscopy was applied to investigate the influence of confinement on the dynamics of dielectric modes in MBBA, dispersed in po rous matrix with parallel cylindrical pores, 200 Angstrom in diameter. Both molecular modes due to the molecular rotation around its short and long ax is were observed in the pores. The confinement results in the modification of the bulk-like modes and of the temperature dependencies of the relaxatio n times. Two low frequency modes due to relaxation of interfacial polarizat ion (collective mode) and reorientational dynamics of molecules at liquid c rystal-pore wall interface (surface mode) were observed. The relaxation tim e of the surface mode has strong glasslike temperature dependence.