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Common Thickening Agents in Detergents

Thickening agents can increase the viscosity of a system, keep the system in a homogeneous and stable suspended or emulsified state, or form a gel. Most common thickening agents also have emulsifying properties. They can be divided into two major categories: natural thickening agents and chemical thickening agents.

Liquid detergents usually require a certain consistency, i.e., viscosity, for several reasons: one is the sensory need, such as dishwashing liquid; the second is ease of use and transportation, reducing volatility, and improving product stability, such as those containing disinfectants; the third is the specific requirements of some detergents, such as needing clingability, so the detergent can remain and function effectively, such as toilet cleaners and hard surface cleaners.

Currently, there are more than 200 common thickening agents in the daily chemical industry, mainly including inorganic salts, surfactants, water-soluble polymers, fatty alcohols, fatty acids, etc.

Inorganic salts used as thickening agents are generally surfactant aqueous solution systems, with the most commonly used inorganic salt thickening agent being sodium chloride, which has a significant thickening effect. Usually, the presence of inorganic salts increases the association number of micelles, converting spherical micelles to rod-shaped micelles, thereby increasing viscosity. Liquid detergents often use sodium chloride as a thickening agent, but if the amount of sodium chloride is too high, it will compress the double electrical layer thickness on the micelle surface, destroying the surface active agent's charged adhesion effect, thus reducing viscosity.

Common Thickening Agents: Fatty Alcohols and Fatty Acids

They can be considered as nonionic surfactants, possessing both lipophilic and hydrophilic groups. The presence of a small amount of these organic compounds significantly affects the properties of surfactants, such as surface tension, with their effect size increasing linearly with the length of the carbon chain.

Common Thickening Agents: Chemical Thickening Agents

Sodium Carboxymethyl Cellulose

Chemical formula: C8H11NaO5n, this chemical thickening agent is a carboxymethyl etherified cellulose, an anionic linear polymer compound. Its molecular structure consists of cellulose glucose units connected by ether bonds to carboxymethyl groups.