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A series of paraffin (Pn)@silica (SiO2) microencapsulated phase change materials (MEPCM) were synthesized by sol‐gel process using tetraethyl orthosilicate (TEOS) and silane coupling agent as precursors. The morphology and chemical compositions of Pn@SiO2 microcapsules were characterized by SEM and FT‐IR, and thermal energy storage capacity was tested by DSC. The results showed that the Pn@SiO2 microcapsules modified with 3‐methacryloxypropyltrimethoxysilane (MPS) had a desirable phase transition enthalpy (184.12 J/g). Meanwhile, the contact angle and leakage rate of Pn@SiO2 microcapsules were analyzed, and the data indicated the contact angle of Pn@SiO2 microcapsules was significantly improved and the leakage rate of Pn@SiO2 microcapsules was reduced to different degrees by modification with silane coupling agents. The main reason is that the modification of silane coupling agents improves the wettability of silica on the surface of paraffin wax, which makes the aggregation of silica on the surface of paraffin more efficient. Among them, the Pn@SiO2 microcapsules modified by MPS showed the most significant reduction in leakage rate, which was reduced from 8.38 % to 1.24 %. Pn@SiO2 microcapsules modified by MPS not only showed outstanding latent heat‐storage/release capability with a high capacity but also exhibited good shape stability, high thermal stability and excellent phase‐change reliability and durability. [ABSTRACT FROM AUTHOR]

Shape-stabilized phase change material (SSPCM) are widely used as energy storage materials due to its advantages of easy preparation and adjustable scale. But the thermal conductivity enhancement of SSPCM still need to be further studied to improve the energy storage efficiency. In this work, silicone rubber (SR)/paraffin@SiO 2 (Pn@SiO 2)/graphene nanoplates (GNPs) shape-stabilized phase change materials (SPG) with different GNPs content were prepared. Pn@SiO 2 and GNPs can be homogeneously dispersed in the SR matrix due to the enhanced interfacial compatibility between Pn@SiO 2 and SR. The leakage rate of SPG composites was as low as 0.25% due to the protection of SiO 2 shell, SR matrix and GNPs. The SPG composites had excellent thermal storage properties, with the enthalpy about 50 J·g−1. The thermal conductivity of SPG composites was improved with the content of GNPs, the thermal conductivity of SPG reach 0.989 W·m−1·K−1 at a GNPs content of 10 phr. The low hardness of SPG composites above the phase change temperature can provide a more cohesive surface when applied to heat dissipation. The heat dissipation of the SPG composites in electric devices was simulated and demonstrated that the addition of GNPs made the heat dissipation rate of the SPG composites increased significantly. Therefore, the SPG composites can be applied in thermal energy storage and heat dissipation of electronic devices. [Display omitted] • The thermal conductivity enhancement of SSPCM was further discussed. • The interfacial compatibility of components in the SSPCM was enhanced by the rational strategy. • The leakage-prevention performance of SSPCM was improved with the multiple protection. • The thermal conductivity of SSPCM reach 0.989 W·m−1·K−1 due to the well-dispersed GNPs and Pn@SiO 2 in SR. • Numerical simulation was used to predict the thermal performance of SPG composites. [ABSTRACT FROM AUTHOR]

Inorganic hydrated salts possess high latent heat of phase transition and are promising phase change materials (PCMs). However, the issues of supercooling, low thermal conductivity, susceptibility to leakage, and phase separation significantly impediment the practical applications of inorganic hydrated salts. In this study, it is proposed to decrease the inorganic hydrated salt supercooling degree by increasing the surface roughness of the porous material and to load the nucleating agent silver (Ag) onto polydopamine (PDA) modified melamine foam (MF) by electroless plating to obtain 3D porous Ag foams, which are then utilized as support materials. The results demonstrated that the 3D porous Ag foam compounded with barium hydroxide octahydrate (BHO) can ameliorate the shortcomings of leakage and reduce the supercooling degree in the cooling process. The composite not only exhibits high enthalpy of over 248.5 J/g and high thermal conductivity of 1.82 W·m−1·K−1 but also has a low supercooling degree of 0.21 ℃. Furthermore, the composites exhibited superior shape stability and thermal cycling stability. This study provides an effective method for reducing the supercooling degree of inorganic hydration salts. [Display omitted] [ABSTRACT FROM AUTHOR]

Hydrated salt phase change materials (PCMs) have the advantages of high energy storage density and low cost, and have great application prospects in the field of phase change energy storage. However, the problems of supercooling, phase separation and leakage of hydrated salt PCMs limit their further applications. In this work, we designed and fabricated Cu-coated melamine foam (MF)/barium hydroxide octahydrate (BHO) shape-stabilized phase change materials (SSPCMs) with low supercooling. MF was used as supporting material and Cu as a nucleating agent and thermal conductivity enhancer by loading it onto MF via electroless plating. BHO was then encapsulated into the MF@Cu skeleton through vacuum impregnation to obtain BHO@MF@Cu SSPCMs. The results demonstrated that BHO@MF@Cu SSPCMs not only present very low supercooling degree of 0.12 °C and high thermal energy capacity of 247 J/g, but maintained a latent heat of phase transition of 229.3 J/g with little change in enthalpy after 100 thermal cycles. Moreover, compared to BHO, SSPCMs exhibited high thermal conductivity of 1.687 W m−1 K−1, excellent shape stability, and thermal cycling stability. In summary, BHO@MF@Cu SSPCMs with low supercooling degree were prepared by electroless plating and vacuum impregnation in this study, which provides a new strategy to reduce the supercooling degree of hydrated salt PCMs. [Display omitted] [ABSTRACT FROM AUTHOR]