Non-ionic Surfactants

In detergents and cleaning agents, surfactants serve as so-called "detergent substances". Like all surfactants, non-ionic surfactants consist of a hydrophilic ("water-loving") and a hydrophobic ("water-repellent") part. Nonionic surfactants do not contain dissociable functional groups, which means that they do not separate into ions in water. This is where the name "non-ionic surfactants" comes from.

The HLB value (hydrophilic-lipophilic balance) indicates the mass ratio between the hydrophilic and lipophilic parts of a surfactant. Surfactants with a low HLB value have good fat-dissolving properties, a high HLB value results in good wetting of hydrophilic surfaces. The HLB value is calculated or empirically determined. There are various methods for this.

In the field of detergents and cleaning agents, non-ionic surfactants are often used as fat solvents in household cleaners and dishwashing detergents. In textile detergents, they are typically used in combination with anionic surfactants. Non-ionic surfactants are also used in the cosmetics industry, in paints and coatings and in construction chemicals.

The cloud point is the temperature at which a non-ionic surfactant solution becomes turbid. The higher the HLB value, the higher the cloud point. The cloud point is therefore an important characteristic of the particular surfactant and its area of application.

The cloud point is determined in water, 1 % NaCl solution or 25 % butyl diglycol solution, depending on the method used. The cloud point also depends on the surfactant concentration.