The stabilizing effect of expanded graphite on the artificial aging of shape stabilized phase change materials

Natural aging of shape stabilized phase change materials based on paraffin wax

“…Blends containing EG assigned lowering of CI values due to increasing stability of blend caused by presence of EG. Similar trend, increasing of photostability of SSPCMs based on W was due to presence of EG [26].…”

“…Sobolciak et al investigated artificial aging of PCMs based on linear low density polyethylene and paraffin wax modified with various amounts of expanded graphite. It was found that expanded graphite significantly suppresses leakage of paraffin wax from the material over time and also improves their photo oxidation stability [26]. Accelerated thermal cycle test of polyethylene glycol of molecular weight 6000, as PCM for solar thermal energy storage was realized by Sharma et al [27].…”

“…Therefore, FTIR spectroscopy is helpful tool to study aging of PCMs by characterizing creation of various functional groups (such as carbonyl, hydroxyl, carboxyl, etc.) created due to exposing of material to heat, sun and humid environment [26].…”

The Effects of Using Aluminum Oxide Nanoparticles as Heat Transfer Fillers on Morphology and Thermal Performances of Form-Stable Phase Change Fibrous Membranes Based on Capric–Palmitic–Stearic Acid Ternary Eutectic/Polyacrylonitrile Composite

“…According to the literature, the disadvantage of liquid leakage of organic solid–liquid PCMs can be overcome by combining them with supporting materials to develop form-stable PCMs through different methods such as absorbing method [ 9 , 10 ], miniemulsion polymerization [ 11 ], melt mixing method [ 12 ], vacuum impregnation method [ 13 , 14 ], electrospinning [ 15 , 16 , 17 ], casting molding method [ 18 ], physical adsorption [ 19 , 20 ], emulsion evaporation method [ 21 ], and so on. The supporting materials involve various materials including inorganic materials (e.g., expanded perlite [ 9 ], diatomite [ 10 ], expanded vermiculite [ 13 ]) and polymers (e.g., poly(methyl methacrylate) [ 11 ], linear low-density polyethylene [ 12 ], ethylene-vinyl acetate [ 14 ], polyacrylonitrile [ 15 ], polyamide 6 [ 16 ], polyethylene terephthalate [ 17 ], epoxy resin [ 18 ], polyurethane [ 19 ], cellulose acetate [ 20 ], polylactic acid [ 21 ]). Moreover, the overall heat transfer efficiencies of phase transition systems can be improved by adding or dispersing heat transfer fillers with high thermal conductivity such as metal materials (e.g., silver nanoparticles [ 19 ] and copper foam [ 22 ]), carbon materials (e.g., expanded graphite [ 10 , 12 ], carbon fibers [ 14 ], carbon nanotubes [ 23 ], graphene oxide, and graphene nanoplatelets [ 24 ]), and ceramic materials (e.g., hexagonal boron nitride [ 25 ] and aluminium oxide nanoparticles [ 26 ]).…”

“…The supporting materials involve various materials including inorganic materials (e.g., expanded perlite [ 9 ], diatomite [ 10 ], expanded vermiculite [ 13 ]) and polymers (e.g., poly(methyl methacrylate) [ 11 ], linear low-density polyethylene [ 12 ], ethylene-vinyl acetate [ 14 ], polyacrylonitrile [ 15 ], polyamide 6 [ 16 ], polyethylene terephthalate [ 17 ], epoxy resin [ 18 ], polyurethane [ 19 ], cellulose acetate [ 20 ], polylactic acid [ 21 ]). Moreover, the overall heat transfer efficiencies of phase transition systems can be improved by adding or dispersing heat transfer fillers with high thermal conductivity such as metal materials (e.g., silver nanoparticles [ 19 ] and copper foam [ 22 ]), carbon materials (e.g., expanded graphite [ 10 , 12 ], carbon fibers [ 14 ], carbon nanotubes [ 23 ], graphene oxide, and graphene nanoplatelets [ 24 ]), and ceramic materials (e.g., hexagonal boron nitride [ 25 ] and aluminium oxide nanoparticles [ 26 ]). Among the above-mentioned materials, aluminium oxide (Al 2 O 3 ) is a promising ceramic thermal conductivity enhancer due to its outstanding advantages, such as stable chemical property, high thermal conductivity (about 30 W/(m.K)), good dispersity within the solid–liquid PCMs, and greater cost-effectiveness compared to other ceramic materials (e.g., boron nitride).…”