Jul 14, 2021
Silicone surfactants used as new pesticide additives have good wettability, strong adhesion, excellent ductility, pore permeability and good resistance to rain erosion.

1. Good wettability

The ability of surfactants to wet is largely determined by the contact angle between the droplet and the leaf surface. The contact angle or extended area of ​​the spray liquid on the leaf surface is related to the equilibrium surface tension of the spray solution, the chemical properties of the leaf surface, and the morphological characteristics. Although conventional non-ionic surfactants can increase the wettability of the spray liquid, they cannot completely wet the hydrophobic leaf surface, which will inevitably reduce the absorption of active ingredients and reduce the anti-rain effect. Silicone can reduce surface tension more than conventional surfactants, and can act more quickly like alkylphenol ethoxy surfactants. Generally, the surface tension of the aqueous solution of surfactant is above 30mN/m, while the surface tension of the aqueous solution of silicone surfactant is mostly around 20mN/m. The surface tension of the aqueous solution is directly related to the wetting ability and wetting speed of the aqueous solution on the solid surface, especially the hydrophobic surface. The smaller the surface tension, the faster the aqueous solution wets the solid surface, and the larger the wetted area or spread area. There is a thin hydrophobic wax film on the surface of the stems, leaves, and stems of plants. After the pesticide emulsion emulsified with general surfactants is applied to the stems, leaves, and stems of the plants, the wetting speed is slow and the spreading area is small. Due to the capillary effect, many small pores cannot penetrate the pesticides, and the pests that are not wetted by the pesticides can still survive. The same does not help the weeds that need to be removed, because the herbicide cannot penetrate into the pores of the weeds. Adding a small amount of organic silicon surfactant to the herbicide formulation can reduce the amount of herbicide by more than one third. Because the surface tension of silicone surfactant is very low, it can promote the rapid wetting of the pesticide emulsion and penetrate into every small part of the stem, leaf and stem of the plant, so that the effect of the pesticide can be maximized and the action time is greatly extended. 

2. Super ductility

The so-called super ductility means that the ductility per unit diameter of a drop of reagent solution on a hydrophobic surface (such as a plant surface) is at least nine times that of water under the same conditions. Policello. Georga. A proposed to drop a 10 microliter surfactant droplet on a thin layer of polyether, and test its extended diameter after 30 seconds. This property can maximize the coverage and attachment of the pesticide on the leaf surface, and even make the pesticide enter the back of the leaf or the pests hidden in the cracks of the fruit tree to achieve the effect of insecticide and sterilization, thereby greatly increasing the amount of pesticides. effect. Organofluorine surfactants can effectively reduce the surface tension of the solution like organosilicon surfactants, but in terms of ductility, organosilicon surfactants are greatly superior to organofluorosurfactants.

3. Stomatal permeability and rain erosion resistance

Generally speaking, there are two ways to absorb pesticides: one is through the epidermis, which is quite slow and sometimes takes several hours to reach the maximum penetration; the other is through the plant stomata, which is unfortunately only A small amount of special surfactants can be absorbed in this way. Silicone additives can reduce the surface tension to below the critical pressure of leaf wetting (about 25mN/m), so it can promote the penetration of the liquid into the epidermis through the pores. The advantage of this way of absorption is fast absorption, which can reduce rain erosion.

Top Win is one of the leading & professional manufacturers with  more than 20 years' experience, have domestic top-level engineers in silicone surfactant industry. We specialized in producing all kinds of SILICONE BASED new materials and specialized in research, production, sales and marketing in silicone-based performance materials.Provide good OEM&ODM service.Our products are mainly used in polyurethane foam, textile and leather, inks and coatings, paper release coating, personal care and agriculture, etc.