采用正十六烷为芯材,聚砜为壳材,二氯甲烷为有机溶剂,十二烷基磺酸钠与明胶的溶液为水相,在液相中利用溶剂挥发法制备了相变蓄热材料微胶囊。根据微胶囊形成机理将制备过程解耦成两个步骤,先利用微尺度反应器可控产生粒径均一的O/W型液滴,再将液滴在固化浴中脱除溶剂固化得到微胶囊。考察了连续相流速、分散相流速、微通道尺寸等因素对微反应器错流剪切模式产生液滴的粒径及单分散性的影响;并对微胶囊的结构和蓄热特性进行了扫描电镜和差示扫描量热仪的表征。结果表明这种解耦方法能够实现可控制备粒径均匀的相变蓄热材料微胶囊,相变热大于75J·g^-1。
The phase change material (PCM) micro-capsules with polysulfone shell and n-hexadecane core were prepared in this work. In order to control the properties of PCM micro-capsules, such as the size and size distribution, the preparation process was decoupled into two separate stages, firstly, the monodispersed O/W droplets were generated by a micro-reactor; secondly, the droplets were solidified in a bath by solvent evaporation approach. The effects of continuous phase flow rate, disperse phase flow rate, and the micro-channel size on the droplet formation process in the micro-reactor were studied comprehensively. The PCM micro-capsules were characterized by SEM and DSC. The results showed that the size of micro-capsules was uniform, and the latent heat was greater than 75 J · g^-1.