A novel dodecanol/tepexil PCM composite for thermal energy storage in buildings

Phase change materials for thermal energy storage through latent heat have been extensively investigated in the last decade for their high potential for heating and cooling purposes in buildings. This paper presents a novel composite PCM's thermophysical properties formed by dodecanol/tepexil and prepared by the vacuum impregnation technique. Although there have been some past studies on making PCM composites using dodecanol, their enthalpy values have not been as high as expected. Scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), laser flash analysis (LFA), differential scanning calorimetry (DSC), and T-History measurements were used to characterize the PCM composite. Dynamic T-History tests revealed that this PCM Dodecanol/Tepexil composite has a fusion temperature of 24.13 °C and a fusion enthalpy of 118 J g⁻¹ and solidification temperature of 20.41 °C with a solidification enthalpy of 108.35 J g⁻¹. These results are the highest values using impregnation techniques to date in the thermal comfort range that goes from 21 to 26 °C for a mild-tempered climate, where the mean temperature is about 22 °C and high annual thermal oscillations (where PCM or high thermal inertia materials are recommended), as far as the authors are concerned. The resulting thermal conductivity of the dodecanol/tepexil composite was 0.308 W m⁻¹ K⁻¹ at 30 °C. Tepexil particles of less than 250 μm exhibit an average pore size of 9.5, 36, and 250 nm and a BET surface area of 2.1 (m² g⁻¹). Leakage tests on the composite showed a maximum retention rate of 40% dodecanol. It was concluded that this PCM composite dodecanol/tepexil could be considered good candidate material with the potential for energy storage in building applications due to its thermal/chemical stability and high energy storage performance.