碳化硅掺杂改善二元糖醇纳米胶囊的性能

Improving performance of binary sugar alcoholnanocapsules bydoping silicon carbide

甘露醇和肌醇作为具有较高潜热的糖醇相变材料,在中温储热方面具有广阔的应用前景。二元糖醇的相变温度可以通过改变糖醇各组分的比例来调节,因而其应用温度范围与单糖醇相比较宽。糖醇在热循环中存在泄漏、氧化和过冷等问题,对糖醇进行微纳胶囊化和添加成核剂是有效解决措施。采用溶胶-凝胶法制备糖醇胶囊制备了碳化硅掺杂甘露醇和肌醇二元糖醇纳米胶囊,采用差示扫描量热仪、扫描电子显微镜、热重分析仪和热循环试验研究了纳米胶囊的相变特性和热稳定性,探讨了碳化硅的影响。结果表明,纳米胶囊具有较高的相变焓值、包封率和储能效率,热分解温度相比二元糖醇提高了,经过热循环后胶囊的过冷度相对于二元糖醇降低了32.2℃。

Mannitol and inositol,as sugar alcohol phase change materials with high latent heat,have wide application prospects in medium temperature thermal energy storage.The phase change temperature of binary sugar alcohol can be adjusted by changing the proportion of the sugar alcohol components,thus the temperature range of application is wider than that of one-component sugar alcohol.There are some problems such as leakage,oxidation and supercooling during the thermal cycles of sugar alcohols.Micro/nanoencapsulation of sugar alcohols and addition of nucleating agent are effective measures to solve the problems.In this paper,silicon carbide doped mannitol and inositol binary sugar alcohol nanocapsules were prepared.Phase change characteristics and thermal stability of the nanocapsules were studied by differential scanning calorimeter,scanning electron microscope,thermogravimetric analyzer and thermal cycling test,and the influence of silicon carbide was discussed.The results show that the nanocapsules have high phase change enthalpy,high encapsulation rate and high energy storage efficiency.The thermal decomposition temperature is higher than that of the binary sugar alcohol.The supercooling degree of the nanocapsules decreases by 32.2℃compared with the binary sugar alcohol after thermal cycling.