Role of rGO in improving the mechanical and thermal performance of PANI/graphene nanocomposites

Reduced graphene oxide (rGO) is a potential reinforcement for polyaniline (PANI) owing to its high stiffness, thermal stability, and intrinsic lubricity. Considering this, the present study investigates the effect of rGO content on the mechanical, tribological, and thermal properties of Polyaniline/rGO (PANI/G) nanocomposites (NCs) synthesized via in-situ oxidative polymerization with systematically varied rGO content (0.01-0.10 wt%). The samples were then characterized using Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy (EDX). Nanoindentation and nanoscratch testing revealed that hardness, modulus, and wear resistance enhanced with increasing rGO content, while the elastic-plastic indices (H/E and H³/E²) decreased, suggesting a trade-off between stiffness and recoverability. Complementary thermogravimetric analysis (TGA) demonstrated that higher rGO loading (0.10 wt%) improved thermal stability by delaying the onset of degradation and reducing overall weight loss, underscoring the multifunctional reinforcing attribute of rGO. The combined results established that an optimized rGO concentration not only enhances surface mechanical integrity but also significantly improves resistance against thermal decomposition, making PANI/G NCs a potential candidate for structural, protective coating, and high-temperature electronic applications.