Preparation of phase change material–montmorillonite composites suitable for thermal energy storage

A new type of organoclay composite (PMMT) with good heat storage and release capacity was produced by intercalating n-hexadecane with Na–montmorillonite (Na–MMT) in a surfactant-assisted medium. The expansion of Na–MMT galleries by a Na salt of 4-dodecylbenzene sulfonic acid (SDS) solution prior to the intercalation of n-hexadecane enhanced the process. In the XRD analysis, expansions of the d spacings in the (0 0 1) plane were observed in all PMMT samples, indicating that the intercalation of n-hexadecane in the galleries of Na–MMT was successfully achieved. The most successful PMMT sample, prepared by intercalating 9 mmol n-hexadecane per gram of Na–MMT, displayed a high heat capacity (126 J g−1) and good thermal durability. The sample also had a higher thermal conductivity compared to pure n-hexadecane samples. The manufacture of the PCM–clay composites by the method of surfactant-mediated intercalation of n-hexadecane into Na–MMT is recommended to enhance the thermal performance of different thermal storage materials.