Study on Thermal Conductivity and Thermal Diffusivity of Carbon Nanotube Fibers and Films

The successful preparation of macroscopic carbon nanotube(CNT) films is a key direction for the development of organic thermoelectric materials.Since CNT film is only 200 nm thick and with porous and rough surface,characterization of its thermophysical properties becomes extremely difficult.This article presents the use of 3w technique for the measurement of thermal conductivity and thermal diffusivity for single-walled(SW) CNT fibers curled from SWCNT films,and discusses the effect of curly layers on the results and the estimating method for the in-plane thermal conductivity and thermal diffusivity of films.The in-plane thermal conductivity for the two SWCNT films studied is 3.4 W/(m·) and 2.0 W/(m·K),while the thermal diffusivity is 24 mm~/s and 21 mm~/s.The results show that SWCNT films will contribute to the development of low-cost organic thermoelectric materials.