Classification of fluorocarbon surfactants

Like ordinary surfactants, fluorocarbon surfactants can be classified into ionic and non-ionic types according to their polar group structure. The ionic type can also be divided into anionic, cationic and zwitterionic fluorocarbon surfactants.

1, anionic fluorocarbon surfactant:

According to their polar groups (hydrophilic groups) can be divided into carboxylic acids (RfCOO-M), sulfonates (RfSO3-M), phosphates (RfOPO3M) and sulfates (RfOSO3-M), before the industrial application of the three main.

Carboxylate fluorocarbon surfactants: generally in strong acids or high-value cationic aqueous solutions, the solubility is small, but the thermal stability is high;

Sulfonate fluorocarbon surfactants: relatively better oxidation resistance, small sensitivity to strong acids and electrolytes;

Phosphate-fluorocarbon surfactants: relatively poor foaming properties.

2, cationic fluorocarbon surfactant:

Cationic fluorocarbon surfactants are almost all nitrogen-containing compounds, that is, organic amine derivatives. Because the surface particles of most substances are negatively charged, cationic active agents are easily adsorbed.

3, zwitterionic fluorocarbon surfactants:

The molecular structure of zwitterionic active agent contains both acidic and basic groups, and the type of ions displayed depends on the PH value of the solution, that is, the cation type in the acidic medium and the anionic type in the alkaline medium. The acidic groups of amphoteric fluorocarbon surfactants are mainly carboxylic acid groups and sulfonic acid groups, and the basic groups are mainly amino or quaternary ammonium groups. Amphoteric fluorocarbon surfactants have excellent emulsifying properties and are used as emulsifiers in the manufacturing process of fluorocarbon materials, paper, leather and other products.

4, non-ionic fluorocarbon surfactant:

Nonionic fluorocarbon surfactants do not ionize in aqueous solutions, and their polar groups are usually oxygen-containing ether bonds (such as polyoxyethylene). The non-ionic type is more soluble in water and organic solvents (including acid and alkali media) than other types of active agents, and has better compatibility with other types of active agents. Because it does not ionize in water, it has high stability to PH value, and is also less affected by electrolyte and inorganic salt, but because its polarity is composed of a certain number of oxygen-containing ether bonds/hydroxyl groups, it can not be applied to strong oxidizing media, so as not to cause ether bond breakage.