High thermal energy storage and thermal conductivity of few‐layer graphene platelets loaded phase change materials: A thermally conductive additive for thermal energy harvesting

Abstract

Abstract3D‐structured graphite efficiently converted into 2D‐structured few‐layer graphene platelets (FGP) through sequentially controlled top‐down approach by adopting 2‐stage exfoliation. A process of solvent‐phase exfoliation with turbulence energy cascade‐dominated complex fluid dynamics‐assisted vertical diffusion was deployed to agitate the particle to disperse them in a solvent with turbulence to delaminate the layered‐material into thin sheet‐like structured FGP consist of 3 to 10 layers. The underlying critical mechanism involved in fragmentation and delamination to FGP was proposed. The enhancement in thermal conductivity of FGP loaded myristic acid found to be around 32.14%, 171.42% and 383.5% for 1, 3 and 5 wt% of FGP, respectively. Thermal conductivity of phase change materials composites increased with increase in FGP loading and decreased with increase in temperature. A phenomenon of a decrease in latent heat and phase transition temperature with increase in FGP loading was observed.