Influence of polyaniline conducting polymer on thermal properties of phase change material for thermal energy storage

This study focused on an important global issue containing both environmental pollution control and energy storage. Polyaniline has been utilized as a supporting material to load paraffin in order to form highly thermal conducting and shape-stable phase change material (PCM). Three different weight percentages (wt%), i.e., 10, 15, and 20 wt%, of polyaniline have been used to obtain shape-stable composite materials. The paraffin leakage of the prepared samples PPCM1, PPCM2, and PPCM3 has been examined by 500 thermal cycles in a hot air oven at 80 °C. Among three samples, the PPCM3 composite with 20 wt% of polyaniline in paraffin has shown excellent leakage-bearing properties with only ~ 0.06% leakage after 500 thermal cycles. Further, the chemical, structural, and morphological analyses of the PPCM3 composite have been carried out by FTIR, XRD, and FESEM. The thermal performance of the prepared sample has been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis, which revealed that the impregnation of polyaniline polymer has improved the thermal stability and thermal conductivity of paraffin with a small decrement in latent heat capacity of the PPCM3 composite. The latent heat of the composite decreased by 18.36% and thermal conductivity increased by ~ 65.45% for a 20 wt% concentration of polyaniline in paraffin with the maximum latent heat capacity. To check the thermal reliability of the formulated PPCM3 composite, the composite has been subjected to thermal cycling of 500 thermal cycles. With increased thermal conductivity, high latent heat capacity, good shape stability, excellent leakage-bearing capability, and improved thermal reliability, paraffin/polyaniline composite PCMs look promising for application in thermal energy storage areas.