High-gravity-assisted efficient synthesis of avermectin nanopesticides stabilized by carboxymethylcellulose with excellent deposition and multiple response release performance

Sustainable crop protection requires nano-pesticides that combine multi-stimuli-responsive release with excellent droplet deposition and spread. However, simultaneous realization of these two functions is hindered by expensive pesticide-modified composite materials and complex preparation technologies. Herein, by introducing inexpensive carboxymethylcellulose (CMC) with varied characteristics, avermectin nanopesticides (Av@CMC) with an average particle size of 158 nm were instantaneously and continuously synthesized via high-gravity anti-solvent precipitation method in a rotating packed bed (RPB). Compared with the conventional stirred tank, RPB sample has more regular morphology, smaller particle size, and higher drug loading capacity. More importantly, this method is easy to scale up, which may facilitate the large-scale synthesis of nanopesticides. Remarkably, the unique internal composition in CMC interacts with the micro/nanostructures of hydrophobic foliage surface, ensuring the complete deposition and spread of pesticide drops after high-position dripping. The reduced contact angle of Av@CMC (70°) compared with water (108°) confirms that CMC incorporation facilitates uniform surface wetting. Relative to technical avermectin, Av@CMC exhibits superior insecticidal efficacy against Plutella xylostella while maintaining no significant effect on non-target organism. This research presents a promising pesticide application strategy that improves agricultural productivity and supports sustainable agriculture.