The need for improvement of energy efficiency has been required for reducing the amount of energy consumption. The phase change capsules (PCCs), which can deliver the thermal energy by storing the latent heat from solar heat, have been highlighted as one of the solutions. The metallic, inorganic, or polymeric shell coated PCCs had been studied. However, metallic and inorganic shell is corrodible in aqueous fluid, and polymeric shell has low thermal conductivity. Furthermore, because the previously studied capsules have low core content, the capsules have low thermal energy capacity.<br/>In this work, we used Pickering emulsion based encapsulation method to enhance the core content for high thermal energy capacity, and encapsulated the phase change material (PCM) with water-absorbable polymeric shell to enhance the thermal conductivity. Paraffin wax was used as core thanks to its high heat storage capacity and nontoxic properties. And the poly(2-hydroxyethyl methacrylate) (pHEMA), a water-absorbable polymer, was used as a shell because the pHEMA can show high thermal conductivity after absorbing a water. The thermal conductivity of pHEMA were measured according to the water content by LFA, and the thermal conductivity of fully hydrous pHEMA was measured to be 0.45 W/m K which is far higher than the other polymers. The manufactured PCC showed good durability owing to the flexibility and elasticity of hydrous pHEMA. The thermal storage properties of the PCC were measured by DSC, and the thermal storage capability of the PCC was calculated to be 99.7%, which is higher than previously researched other PCCs thanks to its high core content.<br/>Our study demonstrates that the PCCs with water-absorbable polymer are an attractive material for effective thermal storage and delivery. In addition to the use of the PCCs as thermal energy carrier, the PCCs can become an attractive material for various heat sensitive industrial fields, such as wall materials of buildings or houses, refrigerator vehicles, and outdoor wear by storage and release thermal energy.

Phase change capsule with water-absorbable polymeric shell for thermal energy storage and delivery

255th National Meeting (2018)

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