The choice of defoaming agent should meet the following requirements:
The Defoaming Agent Is Insoluble Or Difficult to Dissolve in The Foaming Liquid
In order to deflate foam, the defoaming agent should be concentrated and concentrated on the surface of the bubble. In the case of the defoaming agents, it should be concentrated in an instant. And it should be kept in this state in the case of bubble suppression.
Therefore, the defoaming agent should be oversaturated in the foaming solution. And it is easy to reach the over-saturation state only when the defoaming agent is insoluble. In that case, the defoaming agent is easy to gather on the gas-liquid interface. And it is also easy to concentrate on the bubble. So that it can play a role in the lower concentration state.
In the water system, the molecules of its active components should have strong hydrophobic ends and weak hydrophilic ends. And the HLB value is in the range of 1.5-3. The defoaming agent under this state is the best.
The Surface Tension of Defoaming Agent Should Lower Than The Foaming Liquid
Defoaming agents particles can be immersed and expanded in the bubble film when the surface tension of defoaming agent is lower than that of the foaming liquid. It should be noted that the surface tension of the foaming liquid does not mean that of the solution, but the surface tension of whipping aid solution.
The Defoaming Agent Should Have A Certain Affinity with The Foaming Liquid
The defoaming process is actually competition between bubble collapse velocity and bubble formation rate. So the defoaming agent must be able to quickly disperse in the foaming liquid and rapidly work in the foaming liquid.
But the affinity between the defoaming agent and the foaming liquid is excessive, which will dissolve the defoaming agent. While it is not easy to disperse the defoaming agent without enough affinity. It will have a better effect only with good affinity.
Defoaming Agents Do Not React with The Foaming Liquid
The defoaming agent reacts with the foaming liquid. On the one hand, it will lose its function. On the other hand, it may produce harmful substances and affect the growth of microorganisms.
The Lower Volatile, The Longer Effect Time
The first thing is to make sure the system that needs to use the defoaming agent. It is the water-based system or the oil system.
In the fermentation industry, oil defoaming agents should be used. Such as polyether modified silicone or polyether. The water-based ones can be used in water-based coating industry will use. Like silicone defoaming agent.
How to Choose the Right Defoaming Agents?
Choose right type fo it, and compare the amount of adding and price. Then you can get the best defoaming agent.