摘要
热容和热传导系数是表征热能贮存材料的非常重要的物理量。文中测试了3种多元醇(新戊二醇NPG、三羟甲基氨基甲烷TRIS、季戊四醇PE)的摩尔热容和热传导系数,并从晶体学的角度对实验数据进行了理论分析。氢键对这3种多元醇的热物性能起到了重要的影响作用。当多元醇发生晶体结构相变后,氢键断裂,德拜温度下降,因此摩尔热容发生了突变。同样由于相变后氢键断裂,声子数目增加以及声子速度下降,NPG的热传导系数减小了50%。相变后的晶格振动的格波数增加进一步加深了热传导系数降低的变化趋势。在多元醇中参入平均自由程大的杂质或者加入纤维材料有助于提高多元醇的热传导性能。
Heat capacity and thermal conductivity are very important physical quantities that characterize the thermal performance of heat storage material. The molar heat capacities and the thermal conductivities of neopentyl glycol （NPG） ,tris hydroxy methyl aminomethan （TRIS） and pentaerythritol （PE） were measured by DSC and Hot Disc respectively, and the experimental data were analyzed from the crystallography point of view. The results show that hydrogen bond plays a great role on the thermophysical performances of these three polyalcohols. After the crystal structure phase transition, the hydrogen bonds break, Debye temperature falls, thus leading to the mutation of the molar heat capacity. Because hydrogen bonds break in the course of phase transition, the number of phonon increases, the speed of phonon decreases, and the thermal conductivity of NPG fails by 50%. The change of crystal structure results in the increase of lattice wave number, which further deepens the decreasing trend of thermal conductivity. Blending impurities with long mean free path or fiber materials into polyalcohol can enhance its thermal conduction performance.
出处
《化学工程》
CAS
CSCD
北大核心
2013年第2期38-41,共4页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(B5110350)
华南理工大学中央高校基本科研业务费专项资金资助(D2104550
D2117700)
关键词
多元醇
摩尔热容
热传导系数
氢键
温度
polyalcohol
molar heat capacity
thermal conductivity
hydrogen bond
temperature
