Anisotropic thermal conductivity of aligned liquid-crystalline polymer films dispersed with ZnO nanorods

Abstract

Controlling inorganic nanorods is key to the development of functional devices utilizing their anisotropic properties. In this study, we present the unidirectionally aligned liquid-crystalline (LC) polymer films with a thickness of 20 µm dispersed with ZnO nanorods. The nanorods grafted with LC polymers were synthesized and mixed with polymerizable host LCs in a glass cell, and subsequently the mixture was irradiated with ultraviolet (UV) light to obtain polymer films. Polarized optical microscopy, UV-visible absorption spectroscopy, and transmission electron microscopy revealed that LC polymer-grafted ZnO nanorods were aligned along host nematic LC molecules. Anisotropic thermal diffusivity of host LC and ZnO nanorods was investigated in terms of the alignment direction.