基于季铵盐的相变温度精准调节体系

Precise Adjustment System for Phase Change Temperature Based on Quaternary Ammonium Salt

制备不同质量分数的四丁基氯化铵(TBAC)、四丁基溴化铵(TBAB)、四丁基溴化磷(TBPB)单一溶液及二元复配溶液,探究季铵盐溶液体系的蓄冷特性。通过步冷曲线法和差式扫描量热仪(DSC)确定其热物性变化规律和物质均一性。结果表明,单一及二元季铵盐水溶液的相变温度及水合物生成量,均随质量分数的增大而增大,并在质量分数为35%～40%达到峰值。质量分数达到40%时,单一及二元季铵盐水溶液均可形成类纯物质体系。三种客体物质形成的质量分数为10%～35%的单一及二元复配溶液,潜热为166.5～303.2J/g,可用于0～10℃的蓄冷领域;质量分数为40%的单一及二元复配溶液,潜热为175.7～204.8 J/g,可用于2～13℃的精准温度调节,其中TBPB/TBAC混合体系的温度可调节范围较大。

Different concentrations of tetrabutylammonium chloride (TBAC),tetrabutylammonium bromide (TBAB),tetrabutylphosphonium bromide (TBPB) single and binary aqueous solution were prepared to study the cold storage characteristics of the quaternary ammonium salt solution system.The phase transition temperature and supercooling degree of the solution system were determined by the step cooling curve,and the latent heat of phase change and the uniformity of the substance were determined by differential scanning calorimetry (DSC).The results showed that the phase transition temperature and the amount of semi-cage hydrate formation of single and binary quaternary ammonium salt solutions increased with the increase of concentration,and reached a peak at 35% to 40% mass fraction.Under the condition of 40% concentration,both single and binary quaternary ammonium salt solutions could form a pure material system.10%~35% single and binary compound solution formed by three kinds of guest materials could be used for cold storage application of 0~10℃,with latent heat up to 166.5~303.2 J/g;40% single and binary compound solution could be used for accurate temperature adjustment from 2 to 13℃,with latent heat being 175.7~204.8 J/g,of which the temperature range of TBPB/TBAC mixed system could be adjusted within a bigger range.