Preparation and Characterization of Paraffin/Mesoporous Silica Shape-Stabilized Phase Change Materials for Building Thermal Insulation

Abstract

The use of phase change materials (PCMs) is an attractive method for energy storage and utilization in building envelopes. Here, shape-stabilized phase change materials (SS-PCMs) were prepared via direct adsorption using mesoporous silica (MS) with different pore diameters as the support matrix. The leakage properties, microstructure, chemical structure, thermophysical properties, activation energy, thermal stability and thermal storage-release characteristics of paraffin and SS-PCMs were investigated. The results show that the maximum mass proportion of paraffin in SS-PCMs is 70% when the average pore diameter of mesoporous silica is 15 nm, and the phase change temperature and latent heat of the corresponding SS-PCM are 23.6 °C and 135.4 kJ/kg, respectively. No chemical reaction occurs between mesoporous silica and paraffin and the SS-PCMs exhibit high thermal stability. The high activation energy of the paraffin (70%)/MS1 SS-PCM verifies that the shape and thermal properties can be maintained stably during phase change conversions. The time required for SS-PCMs to complete the thermal storage and release process is reduced by up to 34.0% compared with that for pure paraffin, showing a decline in the thermal conductivity of SS-PCMs after the addition of mesoporous silica. Hence, the prepared paraffin/MS SS-PCMs, in particular paraffin (70%)/MS1 SS-PCM, can be used for storing thermal energy and regulating indoor temperature in buildings.

Construction strategies and thermal energy storage applications of shape‐stabilized phase change materials

“…In recent years, mesoporous SiO 2 (MS) has been widely studied for its excellent properties such as high specific surface area and controllable pore size. 131,132 The pore size of MS is between 2 and 50 nm, which is smaller than that of the porous materials mentioned above. 133 Compared with pure PCMs, when the PCMs are adsorbed by MS, the melting point of PCMs will change greatly.…”

Preparation and Characteristics of Na2HPO4·12H2O-K2HPO4·3H2O/SiO2 Composite Phase Change Materials for Thermal Energy Storage

“…The results indicated that the composite PCM had high light–thermal conversion efficiency. Li et al [ 12 ] investigated the adsorption effect of mesoporous silica with different pore sizes on paraffin. It was found that the silica with the smallest pore diameter had the largest adsorption capacity for paraffin.…”