Multifunctional nanofibrillated cellulose/ZnO@rGO composite films for thermal conductivity, electrical insulation, and antibacterial applications

Abstract

Polymers are widely applied in electronic equipment due to their comprehensive performance. However, the poor thermal conductivity (TC) limits their application in thermal management. In this paper, a series of multifunctional nanofibrillated Cellulose (NFC) composite films with high TC, electrical insulation, and excellent antibacterial properties were prepared by using zinc oxide@reduced graphene oxide (ZnO@rGO) as the fillers. The results show that a thermal conduction pathway is effectively constructed in the NFC/ZnO@rGO composite films with high in-plane TC of 8.07 W·m−1·K−1, far exceeding the 1.10 W·m−1·K−1 of pure NFC film. The insulated ZnO loaded on the surface of rGO cuts off the formation of a conductive path, so that the composite films retain the original electrical insulation (ρs > 1014 Ω, ρv > 1014 Ω·m). Moreover, the composite films exhibit excellent antibacterial properties because of ZnO. Therefore, the multifunctional NFC-based composite films could be applied in various thermal management systems with different requirements.