Thermal transport in 3D porous graphene networks
ABSTRACT :
While pristine graphene has the highest thermal conductivity among all the known materials (up to 5300 W/m.K), 3D porous networks made from graphene based systems lie on other end of thermal conductivity spectrum. The ability to obtain ultra-light weight nano-porous and disordered structure is key in realizing the desired low thermal conductivity, which is useful in thermal insulator applications. In this work, it is proposed to explore 3D graphene-based networks as a tunable thermal insulator and electrical conductor. The 3D networks will be synthesized via. (1) solution-based techniques and (2) chemical vapour deposition. Tunability in thermal conductivity and electrical conductivity were studied as a function of reducing agent concentration. Graphene aerogels with highest reducing agent concentration showed the lowest thermal conductivity of 0.01W/m.K and highest dimensionally scaled electrical conductance of 3.9 S/m while aerogels with lowest reducing agent concentration had thermal conductivity of 0.1 W/m. K and dimensionally scaled electrical conductance as 2.2 S/m. The work probes the correlation between electrical and thermal transport in graphene aerogels.