非载体包覆型农药纳米粒子的作物叶面沉积与剂量转移机制研究

Constructing nanoformulations is the frontier science of pesticide formulation processing, and also an important approach to improve pesticide dispersibility and bioavailability. The foliar deposition and dose transfer efficiency of pesticide nanoparticles on target crops are key issues affecting their effective utilization. There is no wrapping and coupling effect between the active ingredient and the carrier in the non-carrier coated pesticide particles. Their foliar deposition and transfer characteristics are mainly affected by the structure and physicochemical properties of pesticide particles. However, the relevant transport mechanism is not clear, which makes it difficult to improve the effective utilization. Based on the previous work about the construction of pesticide nanoformulations, the theories and methods of colloid chemistry, interfacial chemistry and spectroscopy will be used to study the adhesion, wettability, penetration, diffusion and transport of non-carrier coated particles on crops, taking non-systemic emamectin benzoate and systemic imidacloprid as model pesticides. The research objectives are as follows.. Firstly, to reveal the mechanism of interaction between the microstructure and interfacial properties of nanoparticles and the leaf surface. . Secondly, to identify the differences in the effects of nanoparticle properties on systemic and non-systemic pesticides.. Thirdly, to clarify the foliar deposition and dose transfer mechanisms of non-carrier coated pesticide nanoparticles on crops.. This research will provide a theoretical basis for the development of high-efficiency and environmentally friendly pesticide nanoformulations. It is of great significance for improving pesticide efficacy and reducing cost and environmental pollution.

创建纳米剂型是农药剂型加工的前沿科学，也是提高农药分散性和生物利用度的重要途径。农药纳米粒子在靶标作物上的叶面沉积及剂量转移效率为影响其有效利用率的关键问题。非载体包覆型农药粒子是指载药粒子中有效成分与载体间无包裹、偶联作用，其叶面沉积及转移特性主要受农药粒子自身结构和理化特性影响，因相关转运机制不明确，致使其有效利用率提升困难。本项目在前期农药纳米剂型构建工作的基础上，以非内吸性甲维盐和内吸性吡虫啉为模型化合物，采用胶体化学、界面化学与谱学的分析理论与方法，研究非载体包覆型农药纳米粒子在作物上的附着、浸润以及渗透、扩散、转运等行为，揭示纳米粒子的微观结构及界面性质与作物叶面微纳结构间的互作机理，明确纳米粒子特性对内吸性和非内吸性农药影响的差异性，阐明非载体包覆型农药纳米粒子的沉积与剂量转移机制，为开发高效、环保的纳米农药新剂型提供理论依据，对促进农药节本增效和降低环境污染具有重要意义。

创建纳米剂型是农药剂型加工的前沿科学，也是提高农药分散性和有效利用率的重要途径。阐明农药纳米粒子在靶标作物上的润湿、沉积、滞留及迁移行为是提升纳米制剂有效性及安全性的关键。本项目分别采用湿法介质研磨-冷冻干燥法及自乳化-载体固化法构建了稳定性、叶面润湿与沉积滞留性能优良的吡虫啉纳米棒和甲维盐固体纳米分散体两种非载体包覆型农药纳米制剂，并通过改变制剂组成、制备方法与工艺流程调控载药粒子尺寸构建了相应的微米制剂，揭示了载体对农药固体纳米分散体的性能影响及选择原则，为构建农药纳米制剂及实现传统制剂的纳米化改良提供了技术手段与途径。在此基础上，通过扫描电子显微镜、动态光散射粒度分析仪、表面张力测定仪、接触角测量仪、色谱、质谱等手段系统比较了微米和纳米制剂在粒径、形貌、稳定性以及作物叶面润湿与沉积性能上的差异性，揭示了影响制剂润湿与沉积性能各指标参数间的关系，阐明了影响微米和纳米制剂性能的作用机制，并研究了纳米载药粒子在黄瓜植株中的迁移转运行为，为农药剂型功能优化及高效、环保纳米农药新制剂的设计、构建与合理施用奠定了理论与技术基础，对提高农药有效利用率、促进农药减量增效具有重要意义。