Enhancing the Thermal Conductivity of Randomly Oriented CNT Networks via Welded Junctions

The thermal conductivity of bulk CNT materials based on three-dimensional randomly oriented CNT networks is rather low comparing with that of the individual carbon nanotube, and one of the important reasons has been considered to be the huge intertube thermal resistance. Though intertube thermal resistance can be reduced via welded junctions between the tubes, it is still unknown whether the formation of the welded junctions can enhance the thermal conductivity of random SWCNTs network. In this approach, the calculations of the average number of thermal contacts per SWCNT are compared by two different methods, and influencing factors of the thermal conductivity of random SWCNTs network are discussed; a hybrid macroscopic analytical model is proposed to predict the overall thermal conductivity of the partially sintered randomly oriented carbon nanotube (CNT) networks. Results show that choosing proper fraction of welded contacts can enhance the thermal conductivity of randomly oriented CNT networks effectively.