农药微乳剂热力学稳定性微观机制研究

Studies on the Microscopic Mechanism of Pesticide Microemulsion Thermodynamics Stability

利用冷冻断裂电镜研究方法研究了表观稳定的农药微乳剂的微观结构 ,并通过光散射技术测定了O/W型微乳剂分散质点的流体力学半径 ,同时还测定了相关样品的主要表观指标。试验结果表明 ,随着微乳体系中表面活性剂 /水 (w/w)比值的减小 ,微乳剂分散质点流体力学半径变大 ,直至成为双连续结构 ,并依此提出了一种农药微乳剂热力学稳定的可能机制。这一发现使得从微观机制上解释农药微乳剂的热力学稳定性 ,指导热力学稳定的农药微乳剂的研究开发 ,并从根本上解决农药水基化制剂热贮稳定性这一关键技术问题成为可能。

The cryo fracture electron microscope was used to study the microscopic structure of pesticide microemulsion. The hydromechanical radius(Rh) and distribution(f Rh ) of pesticide microemulsion also has been determined by photo correlation spectroscopy. The investigation shows that the Rh was significantly greater when the ratio of surfactants to water decreased to 20/31 from 27/26, and finally the bicontinuous structure occurred when the ratio of surfactants to water droped to 15/36. The results are of great value for explaining the relationship between pesticide properties and the microscopic structure, and establishing a good method for studying the microscopic structure of pesticide formulation.