目前相变微胶囊的制备普遍采用传统的机械搅拌乳化方法，获得微胶囊的粒径大小难以控制，粒径分布范围较大。本工作采用快速膜乳化技术结合原位聚合法获得窄粒径分布的液体石蜡/密胺树脂相变微胶囊。研究发现，过膜压力和过膜次数对相变微胶囊的粒径大小和分布影响较大，当微孔玻璃膜孔径固定时，调节过膜压力和过膜次数可以控制微胶囊的粒径大小和分布。当使用孔径为10.1 μm的微孔玻璃膜时，采用过膜压力为0.2 MPa、过膜次数为4次时，可以获得粒径分布最窄的液体石蜡相变微胶囊。此时微胶囊的平均粒径为10.84 μm，相对标准偏差仅为0.16，远小于机械搅拌乳化制备的微胶囊的粒径相对标准偏差。且微胶囊表面光滑致密，无明显团聚，具有良好的耐热性能和冷/热循环稳定性，微胶囊包裹率约为80%。此外，快速膜乳化技术的引入大大提高了乳化效率，从而显著提高了微胶囊制备效率，对其他窄粒径分布的低温烷烃相变微胶囊的批量化制备具有重要意义。

Microencapsulated phase change materials have excellent ability to store energy and resist the leakage of phase change materials during the solid-liquid phase change process. Traditional mechanical agitation emulsification method has intrinsic difficulty in preparing phase change microcapsules with uniform and controllable particle size. In this work, premix membrane emulsification was employed to prepare emulsion, and liquid paraffin/melamine-formaldehyde resin microcapsules with narrowed particle size dispersion were successfully prepared by taking advantages of the combination of premix membrane emulsification and in?situ polymerization. The result showed that transmembrane pressure and passes had a great effect on particle sizes and distributions of the resulting microcapsules. And the particle sizes and distributions of microcapsules can be effectively controlled by adjusting the transmembrane pressure and passes. When SPG (Shirasu Porous Glass) membrane with an average pore size of 10.1 μm was used, the liquid paraffin microcapsules with narrowest particle size distribution can be obtained by using transmembrane pressure of 0.2 MPa and transmembrane pass of 4 times. And these microcapsules had an average particle size of 10.84 μm and a relative standard deviation of 0.16. But the relative standard deviation of the particle size of the microcapsules prepared by using the combination of mechanical agitation emulsification and in?situ polymerization was 0.89. It indicated that microcapsules with a narrower particle size distribution can be synthesized effectively by employing the premix membrane emulsification. The surfaces of the microcapsules were smooth and dense, and without any adhesion and reunion. They exhibited excellent heat resistance and cold/heat cycle stability, and the encapsulation ratio was about 80%. Besides, the preparation efficiency of the paraffin microcapsules was greatly improved by using the methods of premix membrane emulsification coupled with in?situ polymerization. These results indicated that the combination of premix membrane emulsification and microencapsulation technology was a promising candidate for the preparations of low temperature alkane phase change microcapsules with narrowed size dispersion.