Abstract：
The development of smart systems for pesticidal delivery presents a significant advancement in enhancing the utilization efficiency of pesticides and mitigating environmental risks. Here an acid-responsive pesticidal delivery system using microspheres formed by the self-assembly of halloysite clay nanotubes (HNTs) is proposed. Insecticide avermectin (AVM) and herbicide prometryn (PMT) are used as two models of hydrophobic pesticide and encapsulated within the porous microspheres, followed by a coating of tannic acid/iron (TA/FeIII) complex films to generate two controlled-release pesticides, named as HCEAT and HCEPT, resulting in the loading capacity of AVM and PMT being 113.3 and 120.3 mg g-1, respectively. Both HCEAT and HCEPT exhibit responsiveness to weak acid, achieving 24 h-release ratios of 85.8% and 80.5% at a pH of 5.5. The experiment and simulation results indicate that the coordination interaction between EDTA2- and Ca2+ facilitates the spherical aggregation of HNTs. Furthermore, these novel pesticide formulations demonstrate better resistance against ultraviolet (UV) irradiation, higher foliar affinity, and less leaching effect, with negligible impact of the carrier material on plants and terrestrial organisms. This work presents a promising approach toward the development of efficient and eco-friendly pesticide formulations, greatly contributing to the sustainable advancement of agriculture.
摘要：
农药投放智能系统的开发在提高农药利用效率和减轻环境风险方面取得了重大进展。在此，提出了一种酸响应性农药递送系统，该系统使用由埃洛石粘土纳米管（HNT）的自组装形成的微球。杀虫剂阿维菌素（AVM）和除草剂prometryn（PMT）被用作疏水性农药的两种模型，并被封装在多孔微球中，然后是单宁酸/铁（TA/FeIII）复合膜的涂层，以产生两种控释农药，被命名为HCEAT和HCEPT,导致AVM和PMT的负载能力分别为113.3和120.3mgg-1。HCEAT和HCEPT都表现出对弱酸的响应性，在pH值为5.5时，24h释放率分别为85.8%和80.5%。实验和仿真结果表明,EDTA2-与Ca2+之间的配位相互作用促进了HNTs的球形聚集。此外，这些新型农药制剂表现出更好的抗紫外线（UV）辐射，较高的叶面亲和力，浸出效果较小，载体材料对植物和陆地生物的影响可以忽略不计。这项工作提出了一种有希望的方法来开发高效和生态友好的农药制剂，为农业的可持续发展做出了巨大贡献。
