基于Pickering乳液的木质素双层微胶囊构建与调控机制

Microcapsules significantly orient the development of pesticide formulations greenization. Using lignin as wall material to prepare microcapsules is the important way to solve the bottleneck problems of poor controlled-releasing and anti-photolysis performance. In this project, double-layer lignin microcapsules with excellent anti-photolysis performance, mechanical strength and slow-release property will be prepared based on interfacial crosslinking of Pickering emulsion, by ingenious combining the rigid and strong insoluble lignin particle crosslinking layer to improve the mechanical strength of microcapsule, and the compact soluble lignin crosslinking layer to achieve controlled-releasing.. Firstly, preparation technology of lignin nanoparticles with controllable particle size will be established by the means of chemical modification and surfactant non-covalent modification. Then, influence mechanism of particle size and molecular structure of lignin nanoparticles done to Pickering emulsion stability will be systematically studied. Finally, the adsorption behavior of lignin nanoparticles on the emulsion drop interface and the controllable synthesis method of lignin microcapsules with different release property will be developed by revealing the regulation law among interfacial crosslinking technics, microcapsule wall structure, controlled-releasing and ant-photolysis performance.

微胶囊是农药制剂绿色化发展的重要方向，以木质素为壁材制备微胶囊，是解决其控释和抗光解性能差等瓶颈问题的重要途径。本项目基于Pickering乳液界面交联制备“内松外紧”的木质素双层微胶囊，巧妙结合不溶性木质素粒子交联层刚性强提高机械强度、水溶性木质素交联层致密实现控释的特点，使其具有优异抗光解效果、机械强度和缓释性能。. 首先采用化学改性和表面活性剂非共价修饰途径，建立粒度可控的木质素纳米粒子制备技术；然后系统研究木质素纳米粒子的粒径和分子结构对其交联活性及Pickering乳液稳定性的影响机制；最后研究木质素纳米粒子在乳液界面吸附行为，揭示“Pickering界面交联工艺—囊壁结构—控释和抗光解效果”的调控规律，建立具有不同释放性的木质素微胶囊可控合成方法。

微胶囊是农药制剂绿色化发展的重要方向。本项目构建了两种木质素微胶囊的制备方法，以解决农药控释和抗光解性能差等瓶颈问题。.首先建立SDS非共价修饰制备木质素纳米粒子新方法，进一步建立“木质素粒子亲疏水性和粒径- Pickering乳液稳定性”的影响规律；在此基础上，开发了两种制备木质素微胶囊的新方法，其一是基于木质素粒子稳定的Pickering乳液，结合“预交联木质素-Fe3+金属配位-界面沉积耦合二次交联”法，制备可控释木质素双层微胶囊；其二是基于木质素粒子稳定的Pickering乳液，结合溶剂挥发法制备木质素微胶囊。研制的木质素微胶囊用于包载易光解农药时，具有优异的抗光解效果和缓释性能。