乳化-内部凝胶化工艺制备2,4-D/膨润土/海藻酸钠微球

Preparation of 2,4- D / bentonite / sodium alginate microspheres by emulsification / internal gelation

以膨润土为改性剂,纳米碳酸钙为交联剂,2,4-二氯苯氧乙酸(2,4-D)为模型药物,采用乳化-内部凝胶法制备了2,4-D/膨润土/海藻酸钠复合微球,并利用光学显微镜和激光粒度仪对微球的形貌和平均粒径分别进行了表征,对乳化-内部凝胶化工艺(油水体积比、乳化剂用量、纳米碳酸钙用量以及搅拌速度)对微球的形貌、平均粒径和载药量的影响进行了探究.结果表明,当油水体积比为5∶1,乳化剂用量为石蜡体积分数的1%,纳米碳酸钙为0.2 g,搅拌速度为400 r/min时,载药微球的粒径分布均一、球形度较好,其平均粒径为640.57μm,载药量为15.66%.这种复合材料可以作为农药载体,有望应用于缓释农药领域.

2,4-D/bentonite/sodium alginate composite microspheres were prepared by emulsification/internal gelation method choosing bentonite as modifier, nano-calcium carbonate as crosslinking agent and 2,4-Dichlorophenoxyacetic acid （2,4-D） was as model drug.Morphologies and average particle size of composite microspheres were characterized by optical microscope and laser particle size analyzer.And the effect of emulsification/internal gelation process （ various oil-water ratio, mass rations of emulsifier and nano-calcium carbonate and stirring speed） on morphologies, average particle size and loading con-tent （LC） of microspheres were investigated.The result showed that while oil-water ratio was 5∶1, mass ratio of emulsifier to paraffin was 1%, nano-calcium carbonate dosage was 0.2 g, stirring speed was 400 r/min, the LC of 2,4-D was 15.66%and average particle size was 640.57μm.This composite materi-al can be used as pesticide carrier and is expected to be applied in the field of pesticide slow-release.