Controlled‐release herbicide spheres: co‐crystallization of 2,4‐dichlorophenoxyacetic acid with l ‐menthol via green oiling‐out process for low leaching and high activity

BACKGROUND: Excessive pesticide soil leaching (>99% loss) poses a critical environmental challenge. This study aimed to develop carrier free, slow release herbicide particles by integrating crystal engineering and spherical particle technology. RESULTS: = 100-600 μm). These cocrystal particles reduced solubility by 21.6%, decreased dissolution rate by >50%, and reduced soil leaching by up to 93%, eliminating the need for carriers and avoiding secondary pollution. The release mechanism was governed by a multiscale diffusion limited process: enhanced hydrogen bonding networks elevated lattice energy, while solution mediated recrystallization transformed nanofibrous microstructures into diffusion restricting lamellar domains. Kinetic modeling indicated a transition from Fickian to hindered diffusion. Biological validation demonstrated superior weed control efficacy against chicory and shepherd's purse. CONCLUSION: This integrated approach establishes a sustainable paradigm for precision agrochemical delivery by significantly reducing environmental leaching while maintaining high herbicidal activity.