The shape stabilization of paraffin phase change material to reduce graphite nanofiber settling during the phase change process

Graphite nanofibers (GNFs) embedded in paraffin phase change material are found to settle to the bottom of the sample when subjected to repeated thermal cycling. The majority of this settling is found to occur over the first heating/cooling cycle. A method is developed to prevent GNF settling by creating a shape stabilized phase change material using high density polyethylene (HDPE) as a stabilizing polymer. The shape stabilized samples reduced or eliminated GNF settling over repeated thermal cycles with as little as 10% HDPE by weight.

► Graphite nanofibers (GNFs) in PCM are found to settle with repeated thermal cycles. ► Most settling is found to occur over the first heating/cooling cycle. ► A method is developed to prevent GNF settling using HDPE and paraffin. ► The samples with 10% HDPE reduced GNF settling over repeated thermal cycles.