Preparation and enhanced heat capacity of nano-titania doped erythritol as phase change material

In this paper, novel nano-enhanced phase change materials (NePCMs) were prepared by two step method. Nano-titania and erythritol were chosen as nano material and phase change material (PCM), respectively. Among many dispersants, triethanolamine (TEA) was proved the most effective one due to its low molecular weight and the carried hydroxide radical. The results showed that the heat capacity of NePCMs was enhanced by the doping of nano-titania. The enhancement was about 40% and 14% in solid and liquid state, respectively, when the volume fraction of nano-titania was only 0.2 vol%. We argued that the increased fraction of atoms located in the metastable interfaces contributed to the increase of specific heat capacity in solid state. While in liquid state, the enhancement of heat capacity was due to the increased interfacial thermal resistance caused by high surface area of nanoparticles.