一种致密的相变储能微胶囊的制备与表征

Preparation and Characterization of Impermeable Microcapsule for Thermal Energy Storage by Phase Change

制备了以聚脲为第一壁材、苯乙烯-二乙烯苯为第二壁材,以相变点在16℃左右的石蜡为芯材的相变储能微胶囊。采用红外光谱、差示扫描量热分析、热重分析测试技术表征了制备的相变储能微胶囊的结构组成以及热性能;采用溶剂淋洗法研究了影响包覆率的因素。结果表明,相变储热微胶囊是复合相变材料,微胶囊的热稳定性好,致密性优良;通过对水油比、乳化剂及苯乙烯-二乙烯苯用量等各因素对微胶囊包覆率影响的讨论,得出在水与油质量比3.2,乳化剂相对于水的质量分数为2%时,加入苯乙烯与二乙烯苯质量比为10∶1混合液的质量分数为6.0%时,其包覆率达81.14%;制备的微胶囊能耐较高温度,在150℃以下无质量损失,且微胶囊储热能力高达80J/g。同时发现,储热能力与芯壁比有关,比值越大储热潜能越高。

Styrene-divinyl benzene copolymer and polyurea resin were used to encapsulate a phase change material by free radical polymerization and interracial polymerization. The shell structure and the thermal properties of the microcapsule were investigated using fourier transform infrared spectroscopy （FT-IR）, differential scanning calorimetry （DSC） and themogravimetry （TG）. The encapsulation efficiency was intestigated by means of solvent drip washing. The influence of different parameters such as the amount of monomer, core-to-coating ratio and the content of emulsifier on the encapsulation efficiency was investigated. The experiment results showed that the microcapsule was a kind of composite phase change material, which was compact and impermeable. When the core-to-coating ratio was 3.2 （ mass ratio ）, the emulsifier content 2% （ mass ratio） , the amount of styrene-divinyl benzene 6.0% , the encapsulation efficiency was up to 81.14%. The microcapsule can withstand a high temperature up to 150 ℃. The melt point of the phase change material was not changed and the heat associacted with the phase transition was up to 80 J/g. The energy capacity depended upon the core-to-coating ratio, and the greater the core-to-coating ratio the higher the heat capacity. It can be used to store energy.