Experimental and numerical study of thermophysical properties of carnauba wax nanocomposites with two-dimensional nanoparticles for sustainable thermal energy storage

The increasing demand for sustainable energy storage has intensified the development of phase change materials with improved thermal performance and environmental compatibility. Petroleum-based phase change materials, such as paraffin wax, provide high efficiency but are non-biodegradable, necessitating bio-based alternatives such as carnauba wax. This study introduced nanoparticle-enhanced phase change materials by dispersing two-dimensional nanoparticles like reduced graphene oxide, graphene oxide, and Ti₃C₂T_x MXene into carnauba and paraffin wax matrices to improve thermal and rheological behavior. Nanoparticle-enhanced phase change materials were synthesized with nanoparticle loadings of 0.1–0.5 wt% and characterized using X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, viscosity measurements, and thermal conductivity analysis, while predictive models were developed using machine learning and validated through computational fluid dynamics simulations. Thermal conductivity enhancements reached 20.4% in carnauba-based composites and 19.6% in paraffin-based composites, while latent heat reductions were limited to 13.3% and 9.3%, respectively. Machine learning models reproduced experimental results with 96.7% accuracy, and numerical simulations confirmed convective heat transfer improvements of up to 19.98%. These findings establish carnauba-based nanoparticle-enhanced phase change materials as sustainable alternatives to paraffin-based systems, combining biodegradability with competitive thermophysical performance for next-generation energy and cooling applications.