Table 1.

Main pesticide microcapsule preparation methods.

Method	Preparation Process	Example
Interfacial polymerization	Two reactive monomers are dissolved in two different solvents. When one solvent is dispersed in another solvent, the two monomers undergo a polycondensation reaction at the phase interface to form microcapsules [17].	Natural pyrethrin nanocapsules [18]
In situ polymerization	Two or more water-soluble monomers are polymerized to form a water-insoluble polymer and are deposited on the surface of the core material for coating [19].	S-ethyl dipropylthiocarbamate, acetochlor, atrazine, methotrexate
Emulsion polymerization	A solvent-insoluble monomer is dispersed in a solvent to form a uniform emulsion via mechanical agitation, high-speed shearing, and vigorous shaking with a surfactant (an emulsifier). Then, the polymerization reaction is initiated to form the polymer to achieve core material encapsulation [20].	Abamectin nanocapsule suspension [21], natural pyrethrin nanocapsules [22]
Membrane emulsification	The dispersion phase enters the continuous phase through a shirasu porous glass membrane under inert gas pressure, and the continuous phase breaks into droplets on the membrane surface by the shear forces of the SPG membrane and droplets.	Chlorantraniliprole nanocapsules [23], avermectin nanocapsules [24]
Solvent evaporation	The wall material and core material are dispersed in the organic phase, added to the solution immiscible with the wall material, and the wall material is precipitated to form the microcapsule by heating and evaporating the solvent [25].	Spinosad nanocapsules [26]
Nano-precipitation	The interfacial interaction between solvent and non-solvent disperses the polymer and drug from the oil phase into the aqueous phase. This material can quickly wrap the drug and obtain nanocapsules through precipitation [19].	Pyrazole azoxystrobin nanocapsules [27], azoxystrobin microcapsules [8]
Double coacervation	Two oppositely charged water-soluble polymers form a wall around the water-insoluble pesticide active ingredient, which is a spontaneous liquid-to-liquid separation caused by electrostatic interactions [19].	Azoxystrobin microcapsules [28]