Development of form-stable natural composite phase change material for effective thermal energy storage and anti-leakage behaviour

There is currently a demand in various sectors of the industry for high-performance, reliable, and sustainable bio-based materials. In this context, a naturally derived biodegradable phase change material (NCPCM) was prepared with composite, low-cost, eco-friendly materials, and characterization was done to increase its Thermal Energy Storage (TES). This study presents a Form-Stable Natural Composite Phase Change Material (FS-NCPCM) that was produced using a melt-blending approach with bentonite clay as a carrier material and graphite powder as an additive to enhance the composite's thermal conductivity. Different mass fractions of bentonite clay and graphite were added to the NCPCM to produce form-stable composites. The produced samples were tested for anti-leakage behaviour, and it was found that bentonite can contain a maximum of 45 % of NCPCM without leakages. Thermal energy storage characteristics, thermal reliability, chemical and physical stability, surface morphology, and thermal conductivity were investigated. Graphite and bentonite clay provided good morphology due to their large surface area and effective dispersion with NCPCM. FS-NCPCM5 composite retained its high latent heat values and excellent thermal energy storage potential of 243.54 J/g from the results of DSC analysis. The thermal conductivity of FS-NCPCM5 was enhanced considerably by 219.43 times compared with raw NCPCM. The thermal cycle results showed that the produced FS-NCPCM5 had good thermal/chemical stability after 2000 cycles. Thus, the developed FS-NCPCM5 can potentially be considered as an additive material for creating green construction components with TES capability.