Retention, a crucial process in pesticide spraying, is closely related to pesticide utilization efficiency and severely impacted by both low surface energy components and micro/nanostructures of foliage. To date, many pesticide carriers have been designed based on either foliar components or structures to enhance pesticide retention. However, as far as we know, there have been no reports taking these two factors into account simultaneously. Herein, we present a novel strategy to address this issue by taking advantage of both non-covalent interactions and topology effect between pesticide carriers and crop leaves. By grafting adhesive catechol-containing polymers onto the surface of hat-shape carriers (HSCs) via a one-step esterification reaction, a series of pesticide-loaded catechol functionalized hat shape carriers (pesticide-loaded Cat-HSCs ) with high loading capacity were successfully prepared. Upon spraying on rice and wheat leaves, these functionalized carriers could target both the micropapillae and nanosplinters on foliage driven by the “hanger-hat” topology effect and non-covalent interactions, resulting in great improvement of foliar affinity, pesticide retention, and flush resistance. Moreover, pesticide-loaded Cat-HSCs possess a 15-day sustained-release property and satisfactory efficacy in controlling wheat powdery mildew. Overall, our resource-saving pesticide carrier provides an effective strategy for prolonging pesticide retention and reducing pesticide loss in agro-production.
Kefei Zhao,Jun Hu,Yue Ma,Tianyue Wu,Yuxia Gao,Fengpei Du
Retention, a crucial process in pesticide application, is heavily affected by the extremely low surface energy and micro/nanostructure of plant leaves. The inadequate retention like bouncing, splashing, and drifting often give rise to severe soil and groundwater pollution. In this article, we present an unprecedented topology-regulation approach that significantly contributes to this issue. A series of pesticide-loaded “hat”-shaped Janus carriers (HJCs) are synthesized via emulsion interfacial polymerization and characterized by scanning electron microscope, thermogravimetric analyzer, energy-dispersive spectrometer, and Fourier transform infrared spectroscopy. Upon spraying on plant leaves, the pesticide-loaded HJCs can embed with the micropapillae and nanosplinters on leaves driven by the “hanger-hat” topology effect, consequently leading to the enhanced retention evaluated by the deposition and flush resistance experiments. Moreover, the release behavior of pesticide-loaded HJCs is found to match the Ritger-Peppas model and finally achieves sustained release. Additionally, the generality of the HJCs synthetic strategy is also studied and applicable to multiple pesticides. This study not only provides a new strategy for increasing pesticide retention on plant leaves but also opens a promising aspect for the applications of Janus carriers in agriculture.
危险品化学品经营许可证（带存储）