New forms of energy based on renewable sources are being developed to reduce our dependence on fossil fuels. The conversion of solar energy into thermal energy using phase change materials (PCMs) is particularly attractive, since they provide the capacity to store energy as latent heat of fusion. Petroleum waxes are mostly used to prepare PCMs due to their large latent heat; however, the use of natural waxes as renewable material represents a promising green and sustainable alternative. Candelilla wax, extracted from Candelilla wax plants (<i>Euphorbia antisyphilitica</i>), presents attractive solar-to-thermal energy conversion and storage properties. However, due to its endemic nature, new strategies for design are needed to achieve a sustainable use.<br/>In this work, highly porous Candelilla wax/graphene composites, containing 15% by weight of graphene, were developed using a water-in-oil emulsion process. Candelilla wax composites present a sponge-like porous morphology, in contrast with lamellar-like morphology obtained for paraffin wax/graphene composites. Candelilla wax composites show superior shape stability and solar-to-thermal energy conversion and storage properties than paraffin wax composites. Surprisingly, the porous Candelilla wax composites achieve a higher latent heat of fusion than non-porous Candelilla wax composites. The process developed in this work allows the production of highly porous PCMs with less wax (60% w/w) as phase change matrix. The results of this work provide new insights into development of more sustainable PCMs using natural waxes.

Highly porous phase change materials based on Candelilla wax as renewable source for solar-to-thermal energy conversion and storage

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.