Modification of physical and thermal characteristics of stearic acid as a phase change materials using TiO2-nanoparticles

Abstract

The present study aimed to introduce a novel method to prepare nanoparticles enhanced phase change materials (NePCMs) with high stability and thermal conductivity. First, the NePCMs were prepared by dispersing titanium dioxide nanoparticles (TiO2-NPs) in stearic acid (SA) with 0.09, 0.26, 0.33, and 0.36 wt% using sedimentation balance method (SBM). Then, the structural, thermal and chemical properties of samples were evaluated. The results of structural analysis indicated that nanoparticles were dispersed uniformly in SA. In the next process, the most likely unstable sample was applied in frequently thermal melting and solidification cycles test. Based on the results, the chemical stability and thermal reliability of NePCMs remained excellent after 250 cycles, which make it proper to be applied in long-term consecutive phase change cycles in the thermal energy storage systems (TES). Finally, the thermal conductivity of the prepared composites increased up to 27%, compared to that of pure SA.