Cubic boron nitride enhanced PCM nanocomposites for solar energy storage and thermal management

Abstract

A nanocomposite phase change material (PCM) was developed by incorporating cubic boron nitride (cBN) nanoparticles into paraffin-based RT54HC at loadings of 0.5-2 wt% for thermal energy storage (TES) and thermal management (TM). cBN nanoparticles was dispersed using ultrasonic, magnetic stirring, and surfactantassisted methods. Structural analyses (XRD, FT-IR, FE-SEM, EDX) confirmed successful integration of cBN without altering the crystalline structure or inducing degradation. Differential scanning calorimetry (DSC) showed that with 2 wt% cBN, the peak melting temperature increased slightly from 55.96 degrees C to 56.07 degrees C, while supercooling decreased from 2.68 degrees C to 1.33 degrees C, indicating enhanced stability. The latent heat decreased from 207 J/g to 190 J/g, and specific heat capacity declined with filler content, reaching 3.02 J/g degrees C at 50 degrees C. Thermal conductivity improved markedly, by 59 % in the solid state (0.196-0.312 W/m.K) and 27 % in the liquid state (0.174-0.221 W/m.K). Thermogravimetric analysis (TGA) further demonstrated improved durability, with the onset decomposition temperature rising to 186.77 degrees C. With a melting point near 54 degrees C, the cBN-RT54HC nanocomposites are suited for solar technologies operating in the 40-70 degrees C range, including photovoltaic/thermal (PV/T) collectors, building-integrated fa & ccedil;ades, and solar-assisted hot water or space heating. Their stability also supports intermediate storage in concentrated solar power plants and solar-driven processes such as drying, desalination, and waste heat recovery. Beyond solar, these PCMs are promising for electronic cooling, battery thermal management, energy-efficient building envelopes, and aerospace systems, offering a versatile and durable thermal solution.