Stimuli-responsive hydrogel as carrier for controlling the release and leaching behavior of hydrophilic pesticide.

In this work, biochar based hydrogel microspheres were fabricated successfully to develop pH and ion strength dual-stimuli responsively controlled-release system for hydrophilic pesticide. Herein, gentian violet (GV) was selected as model hydrophilic pesticide. Taking advantage of the cross-linking reaction, GV was incorporated into biochar and the 3D network-structured hydrogel, guaranteeing a satisfying encapsulation efficiency and sustained release of pesticide. The leaching behavior of pesticide in simulated soil column at different pHs and ion strength was in accordance with the corresponding release performance, and bulk of pesticide was retarded on the surface. In addition, the pesticide carrier had nearly no toxic effect on the cell proliferation and zebrafish embryo, displaying a good biosafety. The work provides a promising strategy with a low-cost and simple procedure that could regulate pesticide release behavior, decrease leaching loss, and improve the utilization efficiency of pesticide.