Temperature-Dependent Thermal and Thermoelectric Properties of Single-Walled Carbon Nanotube Aerogels

Abstract

Aerogels are ultraporous solids that have found a number of uses due to their very low density. Recently, aerogels based on single-walled carbon nanotubes (SWCNTs) have been fabricated and show significant potential for battery, supercapacitor, sensor, and thermal applications due to the electrical, mechanical, and thermal properties of SWCNTs as well as their capacity for functionalization. In this work we report temperature-dependent (100–300 K) measurements of thermal conductivity, electrical conductivity, and Seebeck coefficient for SWCNT aerogels synthesized through a critical point drying technique. Two types of aerogels are considered: an as-grown SWCNT aerogel and one that is coated with multiple graphitic layers (Gr-SWCNT) leading to significantly improved mechanical properties. Thermal conductivity and electrical conductivity were found to be significantly higher for SWCNT aerogels than for other aerogels, even though they have a much smaller density. Gr-SWCNT aerogels were found to have lower thermal conductivities than as-grown samples.