As we all know，surfactants generally consist of two parts: polar groups (hydrophilic groups) and non-polar groups (hydrophobic groups). The non-polar groups of ordinary surfactants are hydrocarbon chains while the non-polar groups of fluorocarbon surfactants are fluorocarbon chains， that is， the hydrogen atoms on the hydrocarbon chains are partially or completely replaced by fluorine atoms. But there is no obvious difference between the two in the structure of the polar group. Therefore fluorocarbon surfactants are surfactants that replace hydrocarbon chains with fluorocarbon chains as non-polar groups in the molecule.
　　1. Anionic fluorocarbon surfactant:
According to its polar group (hydrophilic group), it can be divided into carboxylate (RfCOO-M+), sulfonate (RfSO3-M+), phosphate (RfOPO32-M2+) and sulfate (RfOSO3- M+), the industrial applications are mainly the first three.
　　Carboxylate fluorocarbon surfactants: generally have low solubility in strong acids or aqueous solutions containing high-valent cations, but have high thermal stability;
　　Sulfonate fluorocarbon surfactants: relatively better oxidation resistance, less sensitive to strong acids and electrolytes;
　　Phosphate-based fluorocarbon surfactants: Relatively poor foaming performance.
　　2. Cationic fluorocarbon surfactant:
　　Cationic fluorocarbon surfactants are almost all nitrogen-containing compounds, that is, organic amine derivatives. Since the surface particles of most substances are negatively charged, cationic active agents are easily adsorbed.
　3. Zwitterionic fluorocarbon surfactant:
　　The molecular structure of the zwitterionic active agent contains both acidic groups and basic groups, and the type of ions it exhibits depends on the pH value of the solution, that is, it is cationic in acidic media and anionic in alkaline media. The acid groups of amphoteric fluorocarbon surfactants are mainly carboxylic acid groups and sulfonic acid groups, and the basic groups are mainly amino groups 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 are not ionized in aqueous solution, and their polar groups are usually oxygen-containing ether bonds (such as polyoxyethylene groups). 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。due to its ater does not ionize, so it has high stability to PH value and is less affected by electrolytes and inorganic salts. However, because its polar group is composed of a certain number of oxygen-containing ether bonds/hydroxyl groups, it cannot be used in strong oxidizing media to avoid damage. The ether bond is broken.