Preparation of shape-stabilized phase change materials as temperature-adjusting powder

Abstract

The shape-stabilized phase change materials (PCMs) composed of paraffin wax and silica were prepared in O/W emulsion with cetyl trimethylamine bromide as emulsifier and n-pentanol as assist emulsifier. The paraffin wax (with melting temperature of 29°C, crystallizing temperature of 26°C and latent heat of 142 J/g) served as latent heat storage material and the silica as supporting material, which prevented the leakage of the melted paraffin wax. Silica supporting material was formed in situ via hydrolysis and condensation from low-cost sodium silicate solution with chlorhydric acid and ammonium bicarbonate as neutralizing agent. The thermogravimetry (TG) curves show that the composite has a thermal stability superior to that of paraffin wax and that the content of paraffin wax in the composite is 65wt%. The maximum latent heat and its relevant melting point of composite are 95 J/g and 30°C, respectively.

A Review of Composite Phase Change Materials Based on Porous Silica Nanomaterials for Latent Heat Storage Applications

“…Paraffin–porous silica composites can be obtained through direct sol-gel synthesis of the silica matrix in the presence of paraffin, a suitable structure directing agent, and sometimes an emulsifier [ 82 , 83 , 84 , 85 ]. Cetyltrimethyl ammonium bromide (CTAB) and n -pentanol as emulsifier were found to give superior results over sodium dodecyl sulfate (SDS) or Span 80 and Tween 80 [ 82 ]. A composite with a heat storage capacity of 95 J g −1 and a m.p.…”