pH敏感微球及其在酸性水中的控制释放性能

p H-Sensitive Microspheres and its Controlled Release Performance in Acidic Aqueous Solutions

采用喷雾干燥法制备pH敏感聚合物Eudragit E100(EPO)包载磷酸氢二钾的微球,硬脂酸镁的加入能有效改善微球的硬度和释放性能。微球响应环境pH的变化,控制磷酸氢二钾的释放速率,从而可用于调节酸性废水的pH值。研究了配方组成和制备工艺对微球粒径、形貌的影响,确定载体材料EPO与硬脂酸镁质量比为35:65;喷雾干燥工艺条件是:进样温度120℃,进样液浓度3%,进样量5 mL·min-1。考察了微球对pH=3的酸性水的控制效果,在1 h内溶液pH迅速增加到6.8,在4 h后降到5左右,并能在相当长的时间保持该pH不变。

K_2HPO_4 entrapped pH-sensitive polymeric Eudragit E100（EPO） microspheres were prepared by spray drying method. Magnesium stearate was added as another carrier material to improve hardness and release performance. The release rate of alkaline K_2HPO_4 is controlled by environmental pH changes, which makes the microsphere suitable for pH adjustment of acidic waste water. The effects of microsphere composition and preparation procedure on microsphere size and morphology were investigated. The optimal conditions are found as： 35/65（W/W） of EPO/magnesium stearate, 120℃ injection temperature, 3% injection concentration and 5 mL·min-1 injection volume. The pH adjustment ability of the microspheres in pH = 3 acidic water was examined, and the results show that the pH value increases to 6.8 within 1 h and then decreases to 5 after 4 h. The pH remained unchanged in a long time.