Flexible cellulose composite film incorporated by carbon nitride@graphene oxide prepared by a “compressed-aerogel” approach for efficient thermal management

Heat dissipation films originating from polymer composite with improved thermal conductivity are becoming potential candidates for effective thermal management of next-generation electronic products, profiting from their soft nature and good electrical insulation. In this work, a novel hybrid filler composed of carbon nitride (C3N4) and graphene oxide (GO) is synthesized and further introduced into the cellulose matrix. The electrical insulation of the composite is maintained, attributed to the low electrical conductivity of C3N4. Meanwhile, the bridged chemical bond between C3N4 and GO reduces the interfacial thermal resistance and promotes heat transfer. By hot-pressing the aerogel intermediate, the directional arrangement of fillers is achieved, leading to favorable flexibility and mechanical behavior, and superior in-plane thermal conductivity (5.74 W/mK) of the composite. Thermal characterizations reveal that lower thermal contact resistance (TCR), improved thermal stability, and the relatively lower coefficient of thermal expansion (CTE) together facilitate its practical application in thermal management. The practical performance test is also performed which fully demonstrates its favorable temperature regulation ability, reflected by a 2.7 °C temperature decrement observed in the cell phone battery heat dissipation test.