喷雾干燥法制备微囊的原理是将水溶液以微细液滴喷入到热空气中,待水蒸发后,分离出干燥的固体。由于液体通过喷雾分成很小的粒子,液体表面积变得相当大,促进了热交换,这样水分的蒸发在瞬间完成,故得到几乎是球形的粉末。喷雾干燥可对热不稳定的材料,如酶类进行包微囊,往往没有严重的降解现象。影响喷雾干燥包囊的因素包括:起始液的浓度、粘度、温度及芯料与衣料的比例等。起始液有三种类型,即水溶液、有机溶液和胶囊浆液。喷雾用的起始水溶液,是将水不溶性的芯料,在适当的温度下分散在衣膜材料的水 The principle of the spray drying method for preparing microcapsules is that the aqueous solution is sprayed into the hot air as fine droplets until the water evaporates and the dried solid is separated. Since the liquid is divided into tiny particles by spraying, the surface area of ​​the liquid becomes quite large, promoting heat exchange so that evaporation of moisture is completed in an instant, resulting in an almost spherical powder. Spray drying can be thermally unstable materials, such as enzymes encapsulated microcapsules, often without serious degradation. Factors that affect spray-dried encapsulation include: initial concentration, viscosity, temperature and the ratio of core material to clothing. There are three types of starting solution, namely, aqueous solution, organic solution and capsule slurry. The starting aqueous solution for spraying is a water-insoluble core material which is dispersed in a film material at a suitable temperature