A simple and green preparation process for PRO@PIL-PHS-PEC microcapsules by using phosphonium ionic liquid as a multifunctional additive

Growing concerns about environmental pollution and future food supplies have encouraged the development of controlled release formulation of pesticides. Porous hollow silica (PHS) is an ideal carrier to prepare pesticide microcapsule due to its hollow structure, high surface area, and biocompatibility. However, the cumbersome preparation process of pesticide microcapsule based on PHS severely restricted its extensive development and application in pesticide products. Herein, an improved soft-template method for preparing pesticide loaded PHS was developed by using newly prepared tributylhexadecylphosphonium dicyanamide [P 44416 ][N(CN) 2 ] as the solvent and soft-template agent. The model pesticide prochloraz (PRO) was entrapped inside PHS in situ without loading process during the preparation process and a core–shell structure sphere (PRO@PIL-PHS-PEC microcapsule) was obtained by coating PRO@PIL-PHS with pectin in solution through electrostatic adsorption. The obtained PRO@PIL-PHS-PEC microcapsules had high drug encapsulation efficiency and good photostability with pectinase and pH responsive release properties. Plate antagonism tests and pot trials indicated that the PRO@PIL-PHS-PEC had a significant long-term control efficacy against S. sclerotiorum and no adverse impact on the growth of rapeseed plant. The prepared PRO@PIL-PHS-PEC could effectively reduce the use of pesticides by significantly improving the effective utilization rate and efficacy of pesticides. The simple and green method for synthesis of PRO@PIL-PHS-PEC based on PIL would have great potential for large-scale application of controlled release formulation in the field of pesticides.