Assessing the feasibility of integrating form-stable phase change material composites with cementitious composites and prevention of PCM leakage

In this study, the feasibility of integrating form-stable phase change material (FS-PCM) composites into cementitious composites was investigated. Two different FS-PCM composites were fabricated by using paraffin as functional PCM and hydrophilic and hydrophobic expanded perlite as supporting materials. Because of different surface treatment properties of expanded perlite (EP), their behavior in the cementitious composites were found to be different. Paraffin/hydrophilic EP showed a significant amount of PCM leakage during the integration into cementitious composites. However, no trace of PCM leakage was observed when paraffin/hydrophobic EP integrated into cementitious composites. The instability of FS-PCM in cementitious composite was correlated with surface characteristics of composite PCMs such as contact angle and wetting tension properties. It has been found that the composite PCM having contact angle higher than 90° and negative wetting tension properties successfully prevents the PCM leakage in cementitious composites due to counter-water affinity properties.