Electrospraying Graphene Nanosheets on Polyvinyl Alcohol Nanofibers for Efficient Thermal Management Materials
Jinghao Huo, Guoqiang Zhang, Xiaoyan Yuan, Shouwu Guo
Abstract
With the rapid development of electronic devices, the demand for heat-dissipating materials is increasing. Graphene is a two-dimensional (2D) material with high thermal conductivity. In this study, reduced graphene oxide (rGO) nanosheets are electrostatically sprayed on the surface of electrospun polyvinyl alcohol (PVA) nanofibers. A multilayer rGO/PVA film is fabricated by performing multi-step electrospinning and electrospraying. Finally, the multilayer rGO/PVA films are cut into small pieces and stacked for hot pressing to obtain a flexible H-rGO/PVA- t film (where t denotes the rGO-layer electrospraying time). Scanning electron microscopy images show that an rGO-layer electrospraying time of 4 h resulted in a uniform distribution of rGO sheets on the PVA nanofiber surface to form continuous heat transfer channels. Hence, the H-rGO/PVA-4 composite exhibits high in-plane and cross-plane thermal conductivities of 6.15 and 0.89 W m –1 K –1, respectively, and can be used as a thermal-interface material (TIM) to facilitate effective thermal management. Compared to a hot-pressed pure PVA film, the H-rGO/PVA-4 TIM facilitates a lower surface temperature for light-emitting diode (LED) lamps. This study provides a universal approach for fabricating heat-dissipating composites of 2D materials and polymer films.