Phase change materials coated with modified graphene-oxide as fillers for silicone rubber used in thermal interface applications

Graphene oxide prepared by the Hummers method was chemically modified by 3-aminopropyltriethoxysilane and spherical paraffin@modified graphene-oxide particles (P@m-GO) with a core-shell structure were obtained by an emulsion method. P@m-GO filler/silicone rubber (SIR) matrix composites (P@m-GO/SIR) were prepared by dispersing different amounts of P@m-GO in the SIR precursors, followed by curing and used as thermal interface materials (TIMs). Results indicate that the best TIM had a P@m-GO loading of 60 wt.% and had both a high thermal conductivity (1.248 W·m−1·K−1) and a high latent heat (88.7 J·g−1). Its compression elastic modulus (1.01 MPa) was only one-eighth of that of the pristine SIR (8.16 MPa) due to the plasticity of the paraffin. The paraffin leakage under pressure was low (below 3.98 wt.%) before and after thermal cycling 50 times. These favorable thermal and mechanical properties together with the good cycling stability make it a promising TIM for electronic devices.