摘要
[目的]研究和鉴别农药微乳剂和纳米乳剂,使用阴离子和非离子复合乳化剂,通过改变其组分用量,分别制备了5%阿维菌素微乳剂及其纳米乳剂。[方法]用激光光散射粒径测定仪,考察了2种乳液的胶粒粒径、粒径分布和Zeta电位值,以及不同稀释倍数对这些性能的影响。用透射电镜观察了2种乳液分别稀释1 000、1 500倍后的形态结构。[结果]由于乳化剂和溶剂用量的差异,纳米乳剂显示出不同于微乳剂的储存稳定性,在储存1周后,会析出结晶沉淀,但仍呈透明状。在相同情况下,纳米乳剂的粒径较大,分布较宽,粒径数量分布曲线可能出现双峰。其稀释1 000倍样品的透射电镜照片表明,除球形的胶粒外,还有药物的结晶微粒存在。[结论]选择合适的乳化剂、溶剂种类和用量,对于设计和制备热力学稳定的微乳剂非常重要。适当提高乳化剂用量,有利于在稀释后形成对农药具有保护作用的胶粒形态结构。
[Aims] The aim was to research and identify pesticide microemulsion and nanoemulsion. Avermectin 5% microemulsion and nanoemulsion were prepared with anionic and nonionic composite emulsifiers by changing the dosage of components. [Methods] The particle size, particle size distribution and Zeta potential value of the micelle for the two emulsions, as well as the influence of dilution ratio on these properties, were measured by using laser light scattering particle size analyser. In addition, when the two emulsions were diluted by 1 000 and 1 500 times, the morphological structures of the micelle were observed by transmission electron microscope （TEM）, respectively. [Results] Due to the difference in the dosage of emulsifier and solvent, the nanoemulsion stored for a week showed crystalline precipitation, but still was transparent emulsion, which was different fi＇om the microemulsion. In the same condition, the micelle of nanoemulsion showed a larger size, a wider distribution and has double peak in its particle size distribution curve in comparison with the microemulsion. The TEM images for nanoemulsion diluted by 1 000 times showed that some drug crystalline particles in addition to the spherical micelles. [Conclusions] Appropriate type and dosage of emulsifier and solvent are important to the design and preparation of thermodynamics stability microemulsion. The appropriate increasing dosage of emulsifier is beneficial to form miceUe morphology structures and could protect active ingredient when the microemulsion is diluted.
出处
《农药》
CAS
CSCD
北大核心
2015年第2期91-94,共4页
Agrochemicals
基金
国家自然科学基金项目(31272078)
关键词
阿维菌素
微乳剂
纳米乳剂
乳化剂
avermectin
microemulsion
nanoemulsion
emulsifier
