Thermal performance and shape-stabilization of comb-like polymeric phase change materials enhanced by octadecylamine-functionalized graphene oxide

A series of comb-like polymeric phase change materials, composed of poly(ethylene-graft-maleic anhydride)-g-octadecanol (EMC18) and octadecylamine-functionalized graphene oxide (GO-C18) and graphene oxide (GO), denoted as EMC18@GO-C18 and EMC18@GO, respectively, have been prepared through a solution mixing method. The structure, thermal performance, energy storage and release capability, cycle stability are deeply characterized. Shape-stability for EMC18@GO-C18 and EMC18@GO shows a bigger improvement than that of bulk EMC18 because of the framework role of 2D GO nanosheets. At 160 °C, no liquid leakage appears in EMC18@GO-C18, exhibiting a superior shape stabilization temperature to EMC18@GO, which is contributed by its enhanced interfacial compatibility from the introduced octadecyl side chains. Thermal performance shows a highly dependence upon the content of GO or GO-C18 nanofillers, and the thermal cycling stability reaches 500 times. Four thermal cycles are well repeated for the fabric coated by EMC18@GO-C18-2%, and no energy efficiency loses. The maximum temperature difference and thermal buffering time is -15 °C and 375 s at 70 °C working temperature. Good structure stabilization and thermal performance of EMC18 doped by GO-C18 offers a chance to approach the high-efficient thermal energy storage materials.