Effect of expanded graphite surface modification on phase change materials nanocomposites thermal protection efficiency

Abstract In order to investigate phase change materials (PCMs) thermal energy storage capacity as well as shape stability, PCM nanocomposites were fabricated by employing modified expanded graphite (EG) as a conductive filler and polyethylene glycol (PEG) PCM. To improve PCM composite shape stability, EG surface has been modified by utilizing Toluene 2 and 4 diisocyanate (TDI), ethylene glycol and PEG 600, respectively. Findings have illustrated that for PEG PCM/modified EG nanocomposites, shape stability was achieved at 5 wt.% of modified EG filler with less than 10% of melt leakage for all prepared samples as a consequence of surface adsorption capacity increment as well as adequate compatibility. Furthermore, phase change efficiency was calculated as 98% and in addition, thermal diffusion at PCM melting temperature range was negligible and approximately equal to zero. To conclude, it could be declared that, fabricated phase change material composite had desirable characteristics along with adequate shape stability for thermal energy storage applications.