Preparation and physical and thermal characterizations of enhanced phase change materials with nanoparticles for energy storage applications

•Preparation, characterization, and thermal cycling of nanocomposite phase change materials is presented.•Product nanocomposites increases density, viscosity, melting, and solidification rates compared with base fluid.•pH of the PCMs reduces with nanoparticle addition, especially for sp24 with the CuO nanoparticles.•Rates melting and solidification of PCM sp24 increase by ∼18.7% and 14.3%  respectively when adding 5wt.% CuO NPs.•Rate of melting of sp26 increases by almost 3 times when adding 5.0 wt.% CuO and 5.0 wt.% Al2O3.