Thermal behavior and shape-stabilization of fatty acid eutectics/electrospun carbon nano-felts composite phase change materials enhanced by reduced graphene oxide

Improvement in thermal conductivity and shape-stabilization of lauric-myristic-stearic acid (LA-MA-SA) ternary eutectic mixture phase change materials by incorporating with reduced graphene oxide/carbon nano-felts (RGO/CNFs) were investigated. The RGO/CNFs Supporting Materials were facilely made from amidoxime surface-functionalized polyacrylonitrile (ASFPAN) nano-felts immersed in graphene oxide aqueous through stabilization in air followed by carbonization in argon. Various analytical techniques were employed to reveal the morphological structure and thermal properties of fabricated form-stable phase change materials (FSPCMs). FTIR, SEM, TEM, XRD, EDS and BET characterizations indicated that the RGO/CNFs matrix possessed excellent morphological structure and large specific surface area, so that LA-MA-SA could well dispersed in its 3D porous architecture and well-retain their overall shapes. DSC results showed that the maximum loading capacity of LA-MA-SA reached 73.5%, and the highest melting/crystallization enthalpies of fabricated FSPCMs were 128.1/127.9 kJ/kg, respectively. Hot disk thermal constant analyzer suggested that thermal conductivity of the FSPCMs was 1.88 W/m K, approximately 583% higher than that of neat LA-MA-SA. Temperature-time curves for melting/freezing process indicated that compared with melting/freezing times of LA-MA-SA, the melting/freezing time of fabricated FSPCMs decreased about 55.1/62.7%. The RGO/CNFs might afford a lot of conductive pathways for heat transfer and/or conversion. The FSPCMs exhibited superior shape-stabilization owing to capillary force and surface tension induced by interconnected netlike RGO/CNFs composites. Hence, they can be considered as more promising thermal energy storage material in advanced energy-related devices and building energy conservation applications.