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 porous matrix with parallel cylindrical pores, 200 Angstrom in diameter. Both molecular modes due to the molecular rotation around its short and long axis were observed in the pores. The confinement results in the modification of the bulk-like modes and of the temperature dependencies of the relaxation times. Two low frequency modes due to relaxation of interfacial polarization (collective mode) and reorientational dynamics of molecules at liquid crystal-pore wall interface (surface mode) were observed. The relaxation time of the surface mode has strong glasslike temperature dependence.