采用乳化水加油法,以正丁酸乙酯为溶剂,曲拉通X-100(TX-100)、十二烷基苯磺酸钠(SDBS)为表面活性剂,正丁醇为助表面活性剂,制备水基型氯氰菊酯微乳剂.通过相图法、负染电镜、电导率、表面张力法、动态光散射、表面接触角测定等手段对所制备的氯氰菊酯微乳剂的结构和性质进行了表征,研究了该微乳剂在杨福麦叶面的铺展动力学.结果表明所制备的氯氰菊酯微乳剂为水包油型(ONV),该微乳剂对氯氰菊酯有较好的增溶效应,具有较低的接触角和表面张力,液滴半径在45nm左右:微乳剂在杨福麦叶面的铺展动力学恰好符合二级动力学方程,速率常数分别为0.1090(°)-1·min-1(20℃)和0.1572(°)-1·min-1(30℃),活化能为27.03kJ·mol-1.
Water-based cypermethrin microemulsions were prepared by adding oil to emulsified water, with ethyl butyrate as the solvent, TritonX-100 (TX-100) and sodium dodecyl benzene sulfonate (SDBS) as surfactants, and n-butyl alcohol (n-C4H9OH) as a co-surfactant. The structure and properties of the microemulsions were investigated by determining the phase diagram, and using negative-staining transmission electron microscopy, and conductivity, surface tension, dynamic light scattering, and contact angle measurements. The spreading kinetics of the microemulsions on the leaf surface of Youngfu wheat was also studied. The results showed that the cypermethrin microemulsions followed the oil-in-water model, and had a strong solubilizing effect on cypermethrin. The microemulsions showed a low contact angle, and low surface tension, and the droplet radius was about 45 nm. The kinetics for the spreading of the microemulsions on the leaf surface of Youngfu wheat fitted a second-order kinetic equation. The kinetic rate constants were 0.1090 (°)-1·min-1 (20 ℃) and 0.1572 (°)-1·min-1 (30 ℃), and the activation energy was 27.03 kJ·mol-1.