Development and Laboratory Scale Characterization of a New Hybrid Nano-enhanced Phase Change Material for Solar Thermal Energy Storage

The latent heat thermal energy storage (LHTES) systems using organic phase change materials (PCMs) offer significant advantages, however, they suffer with low thermal conductivity and this limitation restricts their uses in many real applications. This weakness of them has attracted the attention of worldwide researchers. In the present work, a novel hybrid organic phase change material (HOPCMs) using two-step method is prepared by the addition of copper oxide and titanium oxide nanoparticles in different mass fraction ratio for elevating the thermal conductivity of myristic acid (MA) as base PCM. The findings of this experimental work show that with the addition of 75 % CuO and 25 % TiO₂ of total 1 % of combined nanoparticles mass fraction, the thermal conductivity of pure PCM enhances by an amount of 13.16 %. The thermo-physical properties were obtained using differential scanning calorimetry and they show that by the addition of hybrid nanoparticles, PCM does not loses its latent heat by more than 2 %. The chemical and thermal properties were tested by adopting Fourier transform and infrared spectrometer (FT-IR), X-ray diffraction (XRD) technique, and thermogravimetric (TGA) analyzer. The reliability and stability of the HOPCMs were checked by conducting accelerated thermal melt/freeze cycle test for 1000 cycles. The HOPCMs so obtained, reveal the good thermal and chemical properties, and ensure a long-term performance for medium temperature based LHTES systems.