Enhancing Thermal Transport in Partially Reduced Graphene Oxide Films: A Comparative Study of Polymeric Additives

Graphene-based films are promising for advanced thermal management, yet achieving high thermal conductivity typically requires energy-intensive, high-temperature annealing. Herein, we report a systematic study on tuning the structural and transport properties of partially reduced graphene oxide (PRGO) films through the incorporation of polymer additives followed by moderate temperature (1000°C) annealing. Three polymers including chitosan (CS), polyimide (PI), and polydopamine (PDA) are investigated. Structural characterization (SEM, XRD, Raman, XPS) reveals that CS reduces defect density after thermal annealing at 1000°C. Thermal characterization indicates that all additives improve thermal diffusivity, but only CS increases film density, resulting in a net rise in thermal conductivity. For electrical conductivity, CS markedly boosts conductivity, while PI and PDA degrade it. These property trends remain consistent from 10 K to 320 K. Analysis of the temperature coefficient of resistance (TCR) indicates that modified films exhibit lower TCR values closer to that of pristine graphene. Furthermore, low-temperature thermal reffusivity analysis confirms that the polymer additives suppress phonon-defect scattering and enlarge structural domains, with PI uniquely strengthening interatomic bonding. Our results demonstrate that CS is a particularly effective additive for concurrently enhancing both thermal and electrical performance in PRGO films, providing a viable polymer-mediated route for microstructure-engineered graphene-based materials.