Span And Tween Series

As non-ionic surfactants, Span and Tween are mainly used in agricultural pesticide preparations, synergists and auxiliary production because of their excellent emulsification, dispersion, wetting and stability.

1.        Emulsifiers In Pesticide Preparations

Span and Tween are widely used in pesticide emulsion (EC), water emulsion (EW) and other dosage forms. through the combination to achieve stable emulsification of oil-water mixture:

Span Series: Strong lipophilicity (low HLB value, such as pan 80 HLB=4 3), suitable for the preparation of water-in-oil (W/0) emulsion. For example, in herbicides or insecticides, Span80 can be used as an emulsifier to evenly disperse the oil-soluble active ingredient in water.

Tween Series: Strong hydrophilicity (high HLB value, such as HLB=15 for Twain 80), suitable for oil-in-water(0/W) type emulsions. For example, Tween 60 or Tween 80 can enhance the dispersity of pesticides in water and improve the coating effect of the liquid on plant surfaces after spraying.

Combination Application: The combination of Span and Tween can cover a wider range of HLB, significantly improving the stability and durability of the emulsion, For example, the combination of Span-80 and Tween 80can both stabilize the oil phase and enhance the water phase compatibility, which is suitable for complex formulations of pesticide preparations.

2.        Pesticide Efficiency And Stability

Synergistic Effect: Tween enhances the wettability and permeability of pesticides on plant leaves or insect surfaces by reducing the surface tension of the solution, For example, Tween 80 promotes rapid penetration of the herbicide into the epidermis of weeds, reducing the time to effect.

Stabilized Suspensions: In suspensions (SC), the dispersion properties of Span and Tween prevent precipitation of active ingredients and extend pesticide shelf life. For example, Span60 is used in suspension to reduce particle aggregation and ensure liquid uniformity.