乳状液制备新工艺——膜乳化过程实验研究

study on a new technology for preparing emulsionsmembrane emulsification

用膜乳化系统制备了Ｏ／Ｗ型乳状液，考察了乳化时间、平均膜孔径、壁面剪应力、膜两侧压差和乳化剂等因素对乳化效果的影响．实验显示，分散相液滴平均直径不随乳化时间而变化；在此条件下，该直径约是膜平均孔径的５～１２倍．随着连续相一侧壁面剪应力的增大液滴平均直径减小，但当壁面剪应力大到一定值后，减小的幅度变得很小．增大膜平均孔径和膜两侧压差都将增加分散相透过膜的通量．此外，乳化剂分子的吸附速度越快，分散相液滴平均直径越小．

Oil-in-water emulsions were prepared with a membrane emulsification system. The effects of emulsification time, mean membrane pore diameter, wall shear stress, transmembrane pressure and emulsifier on emulsification results were studied. The results show that the mean droplet diameter of disperse phase does not change with emulsification time, it is about 512 times as great as mean membrane pore diameter; with increasing wall shear stress in continuous phase side, the mean droplet diameter decreases, but when the wall shear stress is greater than a certain value, the decreasing becomes very slowly; increasing transmembrane pressure or mean membrane pore diameter can increase the flux of disperse phase. The results also show that dynamic interfacial tension affects droplet size. The faster emulsifier molecules adsorb and lower interfacial tension, the smaller the droplets of the disperse phase.