Does dispersant not refer to surfactants?

Usually, surfactants are associated with other additives, such as dispersants, so why are they different? In fact, surfactants are a wide range of categories, including many auxiliary agents, and dispersants are also surfactants. However, it should be noted that inorganic dispersants are all surfactants, while inorganic dispersants are not surfactants. Next, we will understand their respective properties.

Surfactants are chemicals that can greatly reduce the surface tension of solvents (generally water) or the surface tension of liquid-liquid interface, change the Surface states of the system, and thus have a series of effects such as long-term wetting and rewetting, emulsification and demulsification, dispersion and agglomeration, foaming and defoaming, and solubilization. The special effect played by surfactants is called surface activity.

Dispersants are agents that promote the uniform dispersion of material particles in the medium, forming a stable suspension. Dispersants are generally divided into two categories: inorganic dispersants and organic dispersants. Common inorganic dispersants include silicate (such as water glass) and alkali metal phosphate (such as Sodium triphosphate, Sodium hexametaphosphate and Tetrasodium pyrophosphate). Organic dispersants include triethylhexyl phosphoric acid, Sodium dodecyl sulfate, methyl pentanol, cellulose derivatives, polyacrylamide, Gul gum, fatty acid polyethylene glycol ester, etc. It can also be said that dispersants are additives that can improve the dispersion performance of solid or liquid materials. When grinding solid dyes, adding dispersants helps to crush particles and prevent the aggregation of broken particles, thereby maintaining the stability of the dispersion. The oil-based liquid that is insoluble in water can be dispersed into very small liquid beads under the stirring of high shear force. After the stirring is stopped, it will soon delaminate under the action of interfacial tension. After the dispersant is added and stirred, it can form a stable Emulsion. Its main function is to reduce the interfacial tension between liquid liquid and solid liquid.

Dispersant is an interfacial active agent that exhibits both lipophilic and hydrophilic properties within a molecule. It can uniformly disperse solid particles of inorganic and organic pigments that are difficult to dissolve in liquids, while also preventing the settling and agglomeration of solid particles, forming the necessary reagents for stable suspensions. Surfactants refer to substances with fixed hydrophilic and lipophilic groups that can be oriented on the surface of a solution and significantly reduce surface tension.