Passive thermal regulation by electrohydrodynamically microencapsulated calcium chloride hexahydrate in a resorcinol formaldehyde shell embedded in a paint coating

Abstract

The performance of microencapsulated inorganic phase change material (MPCM) embedded in the paint coating of a panel with respect to thermal regulation has been demonstrated. Microencapsulation was implemented by the electrohydrodynamic atomization of a core-sheath filament with CaCl₂·6H₂O at the core and a resorcinol formaldehyde gel precursor in the sheath. The MPCM particles, with an average overall diameter of 398 nm and a shell thickness of 26.5 nm, were subjected to differential scanning calorimetry to study the phase change process in the encapsulated state. A foil heater was attached to an aluminum panel to simulate the heat flow, which was, in turn, absorbed by the MPCM in the paint layer on the other side of the panel. The melting of the in-place PCM was quantified in reference to the imposed heat flux (∼200 W m⁻²) and MPCM loading. The effect of multiple melt–freeze cycles on the performance was evaluated.