Effects of some nucleating agents on the supercooling of erythritol to be applied as phase change material

Nine nucleating agents, calcium pimelate (CaPi), bicyclic [1, 2, 2]heptane di-carboxylate (HPN-68), a commercially obtained aryl amide nucleating agent (TMB-5), calcium salt of hexahydrophthalic acid (HPN-20E), 1,3:2,4-di-p-methylbenzylidene sorbitol (MDBS) and sodium, potassium, magnesium and calcium salt of benzene-1, 3, 5-tricarboxylic acid (Na 3 BTC, K 3 BTC, Mg 3 BTC 2 and Ca 3 BTC 2 , respectively), were applied to reduce the supercooling of erythritol, and their effects were investigated by cyclic differential scanning calorimetry (DSC). The results revealed that Na 3 BTC and K 3 BTC could not induce erythritol to crystallize under the experiment condition. MDBS could only make erythritol to crystallize at a temperature slightly higher than that of pure erythritol, and the effect was unstable. Mg 3 BTC 2 , Ca 3 BTC 2 and HPN-68 could induce erythritol to crystallize at relatively high temperature, but the peak temperature of crystallizing ( T p, cr ) and the phase change enthalpy of crystallizing (Δ cr H ) decreased greatly as the melting–crystallizing cycles increased. HPN-20E-doped erythritol crystallized at a high temperature with the T p, cr of 69.3 °C at the first cycle, but the T p, cr and Δ cr H varied greatly during the melting–crystallizing cycles. CaPi and TMB-5 could induce erythritol to crystallize at a stable temperature with the T p, cr of about 69 °C and 64 °C, respectively, and with a stable Δ cr H of about 204 and 185 J g −1 , respectively, in all melting–crystallizing cycles. Hence, CaPi- and TMB-5-doped erythritol could be used as PCMs and applied in thermal energy storage in which the energy was absorbed at a high temperature and released at a lower but stable temperature.