Thermal enthalpy regulation of methyl hexadecanoate/silica microcapsules with CTAB as emulsifier maintaining fixed core/shell ratio

The fabrication and thermal enthalpy regulation of phase change materials (PCMs) microcapsules have been researched. Methyl hexadecanoate (MH) melting at about 29 °C was used as PCMs core and encapsulated in silica shell microcapsules by sol–gel method. Based on a fixed core/shell ratio, a series of MH/silica PCMs microcapsules were prepared, and cetyl trimethyl ammonium bromide (CTAB) was used as emulsifier. The morphologies of PCMs microcapsules were studied by scanning electron microscopy. The Fourier transform infrared spectroscopy results exhibited that there was only physical interaction between silica and MH core shell. The heat storage capability and good thermostability of PCMs microcapsules were characterized by differential scanning calorimetry and thermogravimetric analysis. The heating cyclic tests showed that MH in the microcapsules had an outstanding long-term performance. From the results, it was found that the decrease in CTAB content (from 0.60 to 0.03 g) promoted effectively the melting enthalpy of PCMs microcapsules from 18.08 to 71.45 J g−1 with the same core/shell ratio. It provides a promising candidate for the preparation of PCMs microcapsules with adjustable enthalpy and popular price.