Graphene composites for thermal management applications

Affordable materials with high thermal conductivity and low thermal-expansion coefficient are very attractive for thermal management applications. Graphene demonstrates great potential to tune the thermal expansion coefficients of polymer composites while significantly improving thermal conductivity, therefore, graphene-filled polymers are regarded as very promising candidates for thermal interface materials and expected to solve the big challenge of increasing heat dissipation in microelectronic devices. In this paper, graphene sheets were synthesized through chemical exfoliation of graphite flakes and then incorporated into polymer composites by solution casting. Both thermal conductivity and thermal expansion of the resultant composites were investigated. The characterization results indicated a significant improvement of bulk thermal conductivity with low addition of graphene sheets in comparison with neat polymer matrix. The coefficients of thermal expansion (CTEs) of polymer composites were also found to decrease with inclusion of graphene, and the CTEs decrease more significantly with increasing graphene fraction. This study suggests graphene nanocomposites are very promising for thermal management application in electronic industry.