High thermal conductivity regenerated cellulose/carboxylated carbon nanotubes composite films with semi-insulating properties prepared via ionic coordination and hydrothermal synthesis of zinc oxide

With the rapid development of miniaturization and integration of electronic products, its heat dissipation has become the focus of research. In order to improve the heat dissipation efficiency of electronic components, flexible thermal insulation materials are constantly studied. Cellulose has good flexibility and load capacity, which is often used in the preparation of thermal conductivity (TC) matrix materials. In this paper, carboxylated multi-wall carbon nanotubes (C-MWCNTs) were modified by metal ion coordination and hydrothermal synthesis of zinc oxide (ZnO) to prepare semi-insulating thermal conductive fillers, which were dispersed and cast into regenerated cellulose (RC) composite films. The results show that the two modification methods can reduce the probability of phonon scattering and block the electron transport path, so as to improve the thermal conductivity and electrical insulation properties of the films. Especially for RC/C-MWCNTs@ZnO composite films, when the total filler content is 20 wt%, the in-plane TC can reach 11.89 ± 0.19 (W/(m·K)), and the surface electrical resistivity (ρs) is (5.24 ± 0.17) × 106 Ω. Compared with RC/C-MWCNTs composite films, the in-plane TC and ρs of the composites are increased by 94.92 % and 555 %, respectively. Therefore, RC-based composite film has broad application prospects in thermal management.