测试速率对PEG/GO定型相变材料熔融和结晶性能的影响

Effect of Test Rate on Melting and Crystallization Properties of Shape-stabilized PEG/GO Phase Change Materials

以聚乙二醇/氧化石墨烯(PEG/GO)定型相变材料为测试样品,采用差示扫描量热法(DSC)对其熔融、结晶性能进行了表征,研究了测试速率(即升/降温速率)对该相变材料熔融、结晶温度和热焓的影响。结果表明:随着降温速率的增加,PEG/GO相变材料的结晶温度逐渐降低;随着升温速率的增加,材料的熔融温度逐渐提升;测试速率越高,焓值越小;随着GO加入量的增加,升降温时的焓值均呈现降低的趋势;相同GO含量的PEG/GO定型相变材料,其熔融焓总是大于同等测试速率下得到的结晶焓,而且测试速率越快,差值越大;在相同测试速率下,GO的添加量基本不会对PEG/GO相变材料的熔融、结晶温度产生影响。

With polyethylene glycol/graphene oxide（PEG/GO） phase change materials as test samples, the differential scanning calorimetry（DSC） was applied to characterize the melting and crystallization properties of the phase change materials, and the effects of the test rate（i.e. heating rate and cooling rate） on melting temperature, crystallization temperature and enthalpy were studied. The results show that： with the increase of cooling rate, the crystallization temperature of PEG/GO phase change materials decreases; with the increase of heating rate, the melting temperature gradually increases, and the greater the test rate is, the smaller the enthalpy value is; with the increase of GO content, the enthalpy values in cooling and heating process show a lower trend; at the same GO content, the melting enthalpy of the phase change materials is always greater than the crystalline enthalpy obtained under the same cooling rate, and the faster the test rate is, the greater the difference is; under the same test rate, the GO content has little affect on the melting and crystallization temperature of PEG/GO phase change materials.