Core reinforcement strategy enhances the foliar stability and efficacy of electrostatic self-assembled microcapsules

At present, it is vital to develop a stable and efficient pesticide delivery system to optimize pesticide foliar utilization, which could improve control efficacy, enhance resistance to adverse climates, and prolong foliar retention. In this study, reaction monomers methylene diphenyl diisocyanate (MDI) and polycaprolactone diol (PCL) were used to synthesize a polymer network structure for loading the organic phase of pesticides in a micron-reactor, then the shell was formed by sodium lignosulfonate (SL) and didecyl dimethyl ammonium chloride (DDAC) through electrostatic self-assembly, resulting in self-assembled microcapsules and efficient pesticide loading, and the stability and efficacy were discussed.

Self-assembled microcapsules Pyr@MCs-C and Pyr@MCs-V with cores of different mechanical strength and morphological characteristics are realized by regulating the reaction ratio of MDI and PCL. Compared with conventional self-assembled microcapsule Pyr@MCs-S, Pyr@MCs-C and Pyr@MCs-V exhibit stable and unruptured morphology in dehydrated environment. Moreover, self-assembled microcapsules provide similar fungicidal activity as emulsifiable concentrate. Notably, the washout resistance property of Pyr@MCs-C and Pyr@MCs-V increased by 3.20 and 3.51 times, respectively, and ultraviolet (UV) resistances of the two microcapsules increased by 5.72 and 5.02 times, respectively, which promote the control efficiency and prolong the duration.

In summary, this system has simple preparation process and stable foliar performances, making it a promising precise pesticide delivery platform. © 2025 Society of Chemical Industry.