采用高压静电雾化法制备W/O乳化液的实验研究

采用静电雾化方法进行了W/O玉米油乳化液制备的实验研究，在雾化流量2.8~15 mL/min、电极施加电压5.2~11 kV的条件下，用Winner99颗粒图像测试仪测试了所制乳化液的离散相滴径，分析了施加电压及雾化流量对平均滴径及滴径分布的影响. 结果表明，静电雾化法可制备离散相滴径比搅拌法更均匀的乳化液，离散液滴平均滴径约为28 mm且绝大多数液滴直径为20~40 mm，其稳定性明显优于搅拌法所制乳化液. 乳化液离散相滴径与施加电压及雾化流量密切相关，电压增大、雾化电流增大，乳化液离散相滴径急剧减小，滴径分布变窄. 流量增大，单位时间内液滴携带及输运的电量增大，故雾化电流增大；但液滴荷积比随流量增大而减小，故滴径变大，滴径分布变宽. 高电压、低流量有助于获得稳定性更好的乳化液.

Preparation of W/O Corn Oil Emulsion Using High Electrical Voltage Electrostatic Spray Method

The W/O corn oil emulsion is prepared by high electrical voltage electrostatic spray method.In the working ranges of flow rate of 2.8～15 mL/min and applied voltage of -5.2～-11 kV,the dispersed droplet diameters of prepared emulsion are measured using Winner99 particle image analyzer.The results show that the dispersed droplet size distribution of the emulsion prepared by electrostatic spray method is narrower than that of the emulsion prepared by stirring method.Under experimental conditions,the W/O emulsion with an average droplet size of 28 μm and a size distribution range of nearly 20～40 μm is obtained.The stability of emulsion prepared by electrostatic spray is obviously better than that by stirring method.The applied electrical voltage and spray flow rate have significant effects on the size and size distribution of emulsion droplets.With the increase of the voltage,the droplets become fine in size and uniform in size distribution.With the increase of flow rate,the spraying electrical current increases due to more charge transferred by droplets in unit time,whilst the charge density on droplets decreases,this eventually leads to enlargement of droplet size and broadening of droplet diameter distribution.Higher voltage and smaller flow rate will be helpful to obtain the emulsion with better stability.