A, surfactant of foam formation

When mixed surfactant and water, one end of the hydrophilic will dissolve in the water, one end of the hydrophobic group will be out of the water gathered in the water. On the surface of the surfactant, the hydrophobic group will leave the surface of the water, into the air, hydrophilic group soluble in water, side by side on the surface of the water. When water, air into the water, the hydrophobic group will cover the air, become the bubble. General, anionic and cationic surfactants bubble is highest, non-ionic surfactant bubbles are relatively lower.

In most of the process, the bubble is brought about by the negative effects, that is to say we pursue low foam and no bubble of surfactant. But on the contrary, in some areas, such as household chemicals, shower gel cleanser, etc., of pursuit is a bubble, the bubble is exquisite; Again, such as paper deinking in the field of flotation deinking, also need the surfactant has good foaming properties.

The second, which has the function of cleaning low foam surfactant

While discussing low foam surface active agent, must use the condition, process, such as surface active agent of foam in addition to related to its structure, and water hardness, temperature, acid and alkaline pH, pressure etc. There are plenty of contact.

1, soap

The use of soap in hard water conditions, can be called low foam surfactant. Sometimes can use soap to test and to distinguish the soft water and hard water, foam for soft water, foam less for hard water. Mainly because in hard water, soap will be combined with calcium and magnesium ions to form magnesium calcium soap or soap does not dissolve in water, the bubble surface is easy to form a gap, lead to the bubble burst.

2, EO/PO block of fatty alcohol polyoxyethylene ether

As is known to all, fatty alcohol and EO (ethylene oxide) condensation addition, namely AEO series, the introduction of the hydrophilic EO groups, get excellent wetting, emulsification, net washing as well as the high performance of the bubble. And PO epoxy propane is hydrophobic groups, the introduction of epoxy propane can effectively reduce the surface tension of the bubble surface, which is formed by the lead to bubble burst and disappear. But the introduction of PO inevitably reduce the EO content, thereby reducing surfactant emulsion, scattered decontamination performance, etc. So for the embedded EOPO polyether, emulsification, dispersion and other net washing function and low foam must be contradictory. The bubble is lower, other performance will be worse.

3, fatty acid methyl ester ethoxylate and its derivatives

Stearic acid methyl ester of fatty acid methyl ester, especially 18 carbon, itself is a kind of antifoaming agent, so 18 carbon stearic acid methyl ester as raw materials of surfactant and the corresponding performance with low foam, and the performance of low foam, unlike EOPO block polyether segment at the expense of the loss on its net washing performance, so it is quite a practical application value of low foam cleaner.

4, low carbon chain fatty alcohol ether and its derivatives

Low carbon chain fatty alcohol has certain function of defoaming, therefore, with a low carbon chain fatty alcohol as raw material of surface active agent, also the corresponding with the characteristics of low foam, the most common for isooctyl alcohol polyoxyethylene ether, isooctyl alcohol phosphate and isooctyl alcohol ether phosphate has features of low foam. But low carbon chain fatty alcohol derivatives often only has the permeability, the other performance is poorer, which limits its application scope.