利用田口实验设计的NaNO_(3)@SiO_(2)微胶囊及其相变性能

Synthesis and Phase Change Performance of NaNO_(3)@SiO_(2) Microcapsules by Using Taguchi Experimental Design

相变材料(PCM)广泛应用于建筑节能、废热回收和太阳能蓄热等领域。相变材料微胶囊化是近年来能源储存和利用领域的研究热点。微胶囊包封率大小的确定需要兼顾胶囊储能效率和壳层强度。现有文献对高温无机相变微胶囊的报道很少,且未见关于包封率可控的NaNO_(3)微胶囊的报道。本工作采用田口实验设计方法,通过限水式溶胶-凝胶法制备适用于高温应用的NaNO_(3)@SiO_(2)微胶囊,得到了包封率为44.8%~95.0%、包封效率为39.0%~92.9%的微胶囊,揭示了各因素对胶囊包封率的影响。通过对微胶囊的热性能和热稳定性等进行表征发现,微胶囊的储能效率随包封率的增大而提高,但热稳定性随包封率的增大而降低。因此,应根据实际应用的需要制备适当包封率的微胶囊。

Phase change materials(PCM)have been widely used in various fields such as building energy conservation,waste heat recovery and solar energy heat storage.Microencapsulation of phase change materials(PCM)has been a research hotspot in the fields of energy storage and utilization in recent years.The selection of encapsulation ratio of microcapsules needs to balance the energy storage efficiency and shell strength of the capsules.At present,there are few reports on high-temperature inorganic phase change microcapsules,and no study on NaNO_(3) microcapsules with controllable encapsulation ratio has been reported.In this work,the Taguchi experimental design method was adopted to prepare NaNO_(3)@SiO_(2) microcapsules for high-temperature applications by the water-limited sol-gel method.Microcapsules with encapsulation ratios between 44.8%and 95.0%and encapsulation efficiencies between 39.0%and 92.9%were obtained.The effects of various factors on the encapsulation ratio of the capsules were revealed.By characterizing the thermal performance and thermal stability of the microcapsules,it was found that the energy storage performance of the microcapsules increased with encapsulation ratio increasing,while the thermal stability decreased with encapsulation ratio increasing.Therefore,microcapsules with appropriate encapsulation ratio should be prepared according to the requirements of practical applications.