Facile preparation of pH/pectinase responsive microcapsules based on CaCO3 using fungicidal ionic liquid as a nucleating agent for sustainable plant disease management

Abstract

Controlled release formulation of pesticides based on microcapsules is a promising strategy for improving utilization efficiency and reducing adverse effects caused by conventional pesticide formulations. However, the complex preparation process and use of toxic additives limit the development of microcapsules. Herein, a simple and green method was developed to prepare double-shelled CaCO3 microcapsules of pesticide using the newly prepared prochloraz ionic liquid (PRO IL) as a nucleating agent to precipitate CaCO3 on the surface of PRO IL micelles in situ and pectin as a coating agent without a complex post-loading process. The results showed that the obtained spherical microcapsules had pectinase and pH dual responsive release properties. The release of PRO from microcapsules belonged to a non-Fickian behavior controlled by the dissolution and diffusion. The photostability of obtained microcapsules was 1.58 times better than that of PRO EW. The fungicidal tests showed that microcapsules had a long-term efficacy against Sclerotinia sclerotiorum and the control efficacy was 1.65 times that of PRO EW at the same concentration. The genotoxicity tests showed that PRO IL@CaCO3@pectin microcapsules did not increase genotoxicity to cells of Vicia faba compared with PRO EW and encapsulation of pesticides in carriers could reduce genotoxicity of PRO IL to plants. These findings would provide a new strategy for the development of calcium carbonate-based microcapsules which could effectively increase the utilization efficiency of pesticides by improving the photostability and durability in environment.