Preparation And Properties Of Graphene Oxide/ Melamine Resin Phase Change Microcapsules

With the rapid growing of global economy, energy storage becomes more and more serious. Phase change material(PCM) can be used for energy storage and release because of the phase change latent heat during their phase change process, and this is helpful to improve energy efficiency. Encapsulation Technology is one of the most effective methods to solve PCM’s problems during phase change process such as flowing, corrosion, bad compatibility. But micro PCMs with a polymer wall has bad thermal conductivity. Graphene possesses many excellent properties such as high thermal conductivity since it was found in 2004. As the precursor of graphene, graphene oxide(GO) is compatible with most polymers because of the oxygen-containing functional groups on its surface. GO can be a functional additive for the poor thermal conductivity of micro PCMs. In this study, GO/melamine resin(melamine- formaldehyde resin) composite was prepared and its thermal properties were discussed. And then, a novel graphene oxide-modified Melamine resin phase change microcapsule(micro PCMs) containing n-dodecanol was prepared by in situ polymerization. Its structure and properties were studied. At last, the prepared micro PCMs were put into mortar board to make a phase change thermal storage mortar board with thermostat function. The main conclusions were listed as follow:(1) GO was prepared by modified hummers method. GO/ melamine resin composite was prepared by in situ polymerization. Fourier transformation infrared spectroscopy(FTIR)result showed that GO had nothing to do with the structure of MF resin. Thermal conductivity of the GO/MF composite with 0.84 wt% GO could be increased by 32.0% compared to MF without GO.(2) A novel gray micro PCMs containing n-dodecanol with GO/ melamine resin as the shell material was successfully prepared by in situ polymerization.The chemical structure of micro PCMs didn’t change with GO. The prepared GO/micro PCMs were spherical particles with smooth surface.The phase change temperature and latent heat of micro PCMs with 1.0wt% of GO were 26.4 ℃ and 125.2J/g, respectively. The thermal conductivity of GO/micro PCMs with 4.0wt% of GO increased by 66.3% compared with that of micro PCMs without GO.(3) Phase change thermal storage mortar board with thermostat function was prepared by adding the prepared micro PCMs into cement mortar. The prepared micro PCMs/mortar board composite had a phase change temperature of 23℃. When the mass content of micro PCMs in cement mortar is 10wt%, the indoor temperature of building model with mortar board composite is 3.6℃ lower than that of building model with ordinary mortar board after 20 min heating by Infrared light.