Microencapsulation of paraffin wax microspheres with silver

Abstract

Microencapsulation of phase change materials (PCMs) with metallic shell materials is a very innovative and challenging task. This can mitigate the problems related to thermal barrier for conventional nonconductive shell materials as well as enhance mechanical properties of PCM microcapsules. Such microcapsules can be integrated into microelectronic devices for their intermittent thermal management in mission critical components. The present work is aimed at developing a new method to synthesise phase change material encapsulated with metallic shell material and characterising the same. Paraffin wax microspheres were first synthesised and then encapsulated with silver through in situ chemical reduction. Further more, a new set of experiments were identified to analyse the quality of encapsulation. The thermal properties were investigated under differential scanning calorimeter and thermogravimetric analyser. The average diameter of paraffin wax microspheres (PW) is found to be ± 329 um. It reveals from DSC analysis that the enthalpy of fusion is minimum for PW@ Ag-PVA amongst all others. Accordingly, higher deposition of Ag is possible for PW@Ag-PVA. This is also supported by TGA results where PW'SAg-PVA has only 40 per cent mass loss and the remaining samples have 100 per cent. However, even for PW'SAg-PVA the encapsulation is found incomplete. The present work provides knowhow of the difficulties associated with encapsulation of PCMs with metallic shell material.