Wang Liying, Liu Juan, Gao Chong, Yan Xinxin, Liu Junzhi
Institute of Functional Molecules, Shenyang University of Chemical Technology, Shenyang 110142, China.
ACS Omega. 2024 Feb 8;9(7):8229-8238. doi: 10.1021/acsomega.3c08838. eCollection 2024 Feb 20.
The utilization of interfacial polymerization in the preparation of microcapsules with a slow-controlled release has been shown to effectively improve pesticide efficacy and reduce environmental pollution. In this study, polyurea microcapsules loaded with lambda-cyhalothrin were prepared by an interfacial polymerization method using modified isocyanate (MDI) as the wall material and GT-34 as the initiator. The microcapsules were fully characterized by optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, etc., and release behaviors were investigated. The results indicated that the microcapsules had a smooth surface and uniform distribution, the average particle size of the microcapsules was 1.97 μm, and the encapsulation efficiency of lambda-cyhalothrin microcapsules could reach 91.48%. Compared with other commercial formulations, the microcapsules exhibited an excellent sustained release property (>7 days) in a 50% acetonitrile aqueous solution (v/v). Subsequently, in vitro release studies showed that the lambda-cyhalothrin microcapsules could consistently control the release of the core materials at different pH, temperature, and MDI addition amount conditions. The release of lambda-cyhalothrin microcapsules was in accordance with the first-order model release, which was mainly by the Fickian diffusion mechanism. Furthermore, the biological activity on showed that the microcapsules' persistence period was above 21 days, which was longer than that for the emulsifiable concentrate formulation.
界面聚合在制备具有缓释性能的微胶囊中的应用已被证明能有效提高农药功效并减少环境污染。在本研究中，以改性异氰酸酯（MDI）为壁材、GT - 34为引发剂，通过界面聚合法制备了负载高效氯氟氰菊酯的聚脲微胶囊。采用光学显微镜、扫描电子显微镜、傅里叶变换红外光谱、热重分析等对微胶囊进行了全面表征，并研究了其释放行为。结果表明，微胶囊表面光滑、分布均匀，微胶囊平均粒径为1.97μm，高效氯氟氰菊酯微胶囊的包封率可达91.48%。与其他商业制剂相比，该微胶囊在50%乙腈水溶液（v/v）中表现出优异的缓释性能（>7天）。随后，体外释放研究表明，高效氯氟氰菊酯微胶囊在不同pH、温度和MDI添加量条件下能够持续控制芯材的释放。高效氯氟氰菊酯微胶囊的释放符合一级模型释放，主要通过菲克扩散机制进行。此外，对 的生物活性表明，微胶囊的持效期在21天以上，比乳油制剂的持效期更长。
