Preparation And Thermal Properties Of Nano Titania Enhanced Erythritol As Phase Change Material

The heat control system of aircraft demands more powerful and effective phasechange materials (PCM). Erythritol possesses a high fusion heat among numerousmedium-temperature PCMs. In this work, a novel kind of nano-enhanced phase changematerial (NePCM) was proposed and successfully prepared. By introducingnanoparticle into PCM, heat capacity can be improved thus temperature of the systemwill be deceased, and heat conductivity can also be enhanced to homogenize thetemperature distribution of the system. The microstructure and thermal properties ofnano-titania enhanced erythritol composite were investigated.The nano-titania enhanced erythritol was prepared by two step method. Thedispersion mechanism of nano-titania in erythritol suspension was discussed. Results ofX-Ray diffraction and Infrared spectroscopy showed that there was no interface reactionbetween titania and erythritol. Grain size of frozen PCM was refined by the adding ofnano particle and clusters of nano-titania were observed. More clusters were observedwith increasing volume fraction of nano-titania.Differential scanning calorimetry (DSC) was used to measure the phase changepoint, fusion heat and heat capacity of NePCM. The results revealed that, the fusionheat of composite fitted mixture rule very well. The thermal properties of NePCM werediscussed in terms of microstructure. In solid state, both thermal conductivity and heatcapacity were obviously enhaced by the doping of nano-titania. When the volumefraction of nano-titania was only0.2vol.%, thermal conductivity and heat capacity oferythritol was increased by about30%and40%?respectively. While in liquid state, thethermal conductivity was decreased by the introduction of TiO2due to the sinigficantinterfacial thermal resistance between nanoparticle and PCM. We proved that thethermal properties of NePCM depend microstructure and clusters of the nanopariticles.The results of heat protection experiment showed that nano-titania enhancederythritol had great potential for improving thermal storage. When the NePCM (with0.2vol.%nano-titania) was used, the temperature of testing point was4.78C lower thanthat of pure erythritol,52.01C lower than that without PCM.