Antifoam Agent

Definition - What does Antifoam Agent mean?

This is a chemical additive that reduces and hinders the formation of foam in an industrial process by altering the surface tension of a solution.

This additive is used to prevent the formation of foam. It is also added to break the foam that has already been formed. This is also called a Defoamer.

Petropedia explains Antifoam Agent

Industrial processes involve contact of gas or air with fluids. A common problem encountered during this operation is the formation of foam (air bubbles over liquid surface); this poses serious problems which reduce the efficiency of the operation. Antifoaming agents are added to avoid or reduce the foam.

Antifoam Agents influence the strength of interconnected foam films network (lamella) by any of the following mechanisms:
  • Defoaming chemical droplets penetrate into the lamella and spread themselves out thus increasing the surface tension causing the lamella to break. This is called Spreading or Fluid Entrainment.
  • Defoamer droplets penetrate the lamella and form a mixed monomolecular film with the foam which makes the lamella thinner causing foam to break. This is called Bridging or Dewetting.
  • Defoamer containing hydrophobic particles reaches the surface and adsorbs on the surface of the lamella by which surface tension is increased causing it to break.
Defoamers are classified as Oil, Powder, Water and Silicone based Defoamers. The commonly used agents are insoluble oils, silicone compounds, dimethyl polysiloxanes, alcohols, stearates and glycols.
Share this:

Connect with us

Email Newsletter

Subscribe to our free newsletter now - The Best of Petropedia.