Silicone Antifoam Emulsion for Pesticides
Common antifoam/defomers include mineral oil, vegetable oil, fatty alcohol, silicone based antifoam, EO/PO based antifoam, Alkyl polyacrylates, etc. And Silicone Antifoam Emulsion is becoming more widely used.
How does Silicone Antifoam Emulsion work?
Foam is difficult to break down because it is stabilized by the surface elasticity and surface viscosity of its film. Silicones have low surface and interfacial tensions. This enables them to flow easily over the film. They seek out openings between the foam-stabilizing surfactants at the liquid-air interface and occupy them. Silicones' low surface tension and interfacial properties combined with their lack of foam-stabilization properties cause the foam wall to thin and collapse.
by Dow Corning
 |
Advantage of silicone antifoam emulsion:
-
Less reaction with the process ingredients and insoluble in most system, which make the whole system more stable
-
Quick foam knock-down and persistence in antifoaming with very low use rate
-
Wide pH range application
In agriculture, the foam problem affects not only the agrochemical formulation process but also the tank mix before spray.
How to use Silicone Antifoam Emulsion?
Take Pro-DFM as an example:
- For optimal foam control, the antifoam must be completely dispersed in the foam medium. To aid in dispersion, pre-dilute the antifoam with about 1-5 times its volume with water, mix them slowly.
- The diluted material should be used immediately.
- Add the diluted antifoam prior to the point where foaming occurs within the system, if possible.
- Very low concentration, about 7.5ml Pro-DFM per 100L spraying water, or make trials at 50 ppm active silicone antifoam
|
|
But how to deal with the foam produced by silicone surfactants?
|
|
Trisiloxane surfactant is now widely recognized as Super Spreader in agricultural spraying. However, it may produce foam that is difficult to control or destroy with traditional antifoam or even silicone antifoam. The low surface tension of trisiloxane surfactant (usually lower than 21 mN/m) should take the responsibility. Though some antifoam can decrease the foam by a little, it may adversely affect the spreading performance of the spray solution.
Under this situation, there is a need to fix the foam problem in first place. That is, choose a Super Spreader with low foam so as to keep the perfect spray perfomance.
Our PASS-LF is such a silicone Super Spreader with low foam, designed for large sprayer like airplane and trailer sprayer, etc.
|
