Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material

Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material (PCM) are conducted. Paraffin/bentonite composite PCM are prepared by a solution intercalation process. Its composition and structure are characterized by X-ray diffraction (XRD) and scanning electronic microscope (SEM) method. The heat storage and release performances are characterized with differential scanning calorimeter instrument (DSC) curve and temperature–time curves. The results show that the layer distance of bentonite has been increased from 1.49175 nm to 1.96235 nm through organic modification. Paraffin can be intercalated into the layers of bentonite and be made into form-stable composite PCM. The latent heat capacity of the composite PCM is 39.84 J/g. The maximum adsorption ratio of the paraffin in the composite PCM is 44.4%. DSC curve shows that the melting and freezing point of the composite PCM is 41.7 °C and 43.4 °C, respectively, which are approximate to that of paraffin. In addition, the heat transfer rate of prepared paraffin/bentonite composite PCM was enhanced by bentonite. The prepared composite PCM can be used in construction energy-saving and medical care.

► The composite PCM are prepared with solution intercalation method.
► The composite PCM has higher heating rate and cooling rate than that of paraffin.
► The melting and freezing points of the composite PCM are 41.7 °C and 43.4 °C, respectively.
► The latent heat capacity of the composite PCM is 39.84 J/g.
► The composite PCM has good thermal stability and form-stability.