Shape‐Stabilized Phase Change Materials Based on Stearic Acid and Mesoporous Hollow SiO₂ Microspheres (SA/SiO₂) for Thermal Energy Storage

Abstract

The development of solar energy conversion and storage technologies has been attracting considerable attention in recent years. In this paper, a novel shape‐stabilized phase change material (SSPCM) based on stearic acid (SA) and mesoporous hollow SiO2 microspheres (SA/SiO2) was synthesized by an impregnating method. The mesoporous silica microspheres with an additional hollow cavity not only provide high loading capacity but also favor the free crystallization of SA, which is confined in the hollow microspheres by interfacial interaction and capillary action. There is no leakage from the obtained SSPCMs even if the temperature exceeds the melting point of SA. The SA/SiO2 PCM with 70 wt.‐% of SA exhibits high latent heat (reaching up to 135.3 J g–1), and its related thermal conductivity is 0.56 W mK–1, which was enhanced by 56 % relative to that of pure SA. Moreover, the SA/SiO2 composites show excellent thermal stability, which is beneficial for latent heat thermal energy storage (LHTES).

Preparation and thermal properties of shape‐stabilized polyethylene glycol/mesoporous silica composite phase change materials for thermal energy storage

“…It was reported that the weak physical interactions such as capillary effect, surface tension and hydrogen bonding existed between PCM and porous materials, which could lead to a reduction in phase transition temperature . In addition, adding the inorganic porous silica into the organic PCM enhanced the thermal conductivity of CPCMs, which caused an accelerate temperature response and led the reduction of the melting temperature of the sample …”

“…38 In addition, adding the inorganic porous silica into the organic PCM enhanced the thermal conductivity of CPCMs, which caused an accelerate temperature response and led the reduction of the melting temperature of the sample. 39 The theoretical enthalpy (ΔH theo ) of PEG/MS ss-CPCMs is calculated according to the following equation 40 :…”

Preparation and performances of palmitic acid/diatomite form‐stable composite phase change materials

“…In recent years, with the aim to avoid leakage, researchers have developed various methods to encapsulate PCMs, such as direct adsorption, capsulation, and sol‐gel method . The direct adsorption method is commonly to use porous materials as carriers, such as expanded graphite, perlite, montmorillonite, bentonite, and diatomite .…”

“…[12][13][14][15][16] In recent years, with the aim to avoid leakage, researchers have developed various methods to encapsulate PCMs, such as direct adsorption, capsulation, and sol-gel method. [17][18][19][20][21] The direct adsorption method is commonly to use porous materials as carriers, such as expanded graphite, perlite, montmorillonite, bentonite, and diatomite. [22][23][24][25][26][27] The molten PCM is adsorbed into holes of the porous carrier materials utilizing their larger specific surface area and the pressure difference between inside and outside the hole.…”

Graphene Modified Montmorillonite Based Phase Change Material for Thermal Energy Storage with Enhanced Interfacial Thermal Transfer

“…[25,[37][38][39][40], SA/RGO-MMT possesses highly competitive energy storage capacity. The extent of supercooling of SA/RGO-MMT is 1.4 o C, lower than that of pristine SA (1.9 o C) and SA/ MMT (3.1 o C).…”