Abstract:The lignin-based avermectin microcapsules(AVM-CS)were prepared by layer-by-layer polyelectrolytes self-assembly method using sulfonated alkali lignin polyoxyethylene ether / polyethyleneimine as shell materials and avermectin as core material. The microcapsule encapsulation and sustained-release properties were investigated on the effect of core-wall ratio, cross-linking agent dosage, cross-linking reaction pH and NaCl concentration. The optimal parameters of AVM-CS were determined: core ratio = 2/5, glutaraldehyde content of 2%, cross-linked pH = 8, 1 mol / L NaCl solution in the capsule. The prepared AVM-CS was in the form of irregular spherical particles with a particle size ranging from 1 to 5 μm. The sustained-release property of AVM-CS was similar to that of avermectin microcapsule prepared from polyurethane wall material, but the release of AVM-CS was relatively complete and the utilization rate of AVM-CS was higher.