Molecular and collective relaxation in deeply supercooled confined liquid crystal

Abstract We report on non-Debye relaxation of fluctuations of director orientations observed in dynamic light scattering experiments for 4- n -pentyl-4 ′ -cyenobiphenyl (5CB) confined to random pores with average pore sizes of 100 A. The relaxation due to reorientations of molecules around short axes is also found to be of non-Debye type in confined 5CB. The relaxation time of this process in deeply supercooled state shows glass-like temperature dependence. We found that the dynamics of the librational mode are totally different from the behavior observed in investigations of relaxation due to reorientation of molecules around their short axis.