How do nonionic detergents form electrically neutral particles in water?

Nonionic detergents are a class of synthetic detergents that do not ionize in solution, meaning they do not produce electrically charged particles like anionic or cationic detergents. Instead, they form electrically neutral colloidal particles in water.12

This neutrality is a result of their specific chemical structure. These detergents are typically synthesized by condensing a hydrophobic group—such as an alkylphenol or a long-chain alcohol—with a long ethylene oxide chain. During this condensation reaction, the ethylene oxide molecules form a chain that links to the hydroxyl group of the hydrophobic compound.23

Because these molecules lack the ionic (polar) groups found in other detergents (such as the sulfo or carboxylate groups), they do not dissociate into ions when dissolved. The hydrophilic portion of the molecule, which allows it to remain soluble in water, consists of this non-ionizing ethylene oxide chain, resulting in a molecule that remains electrically neutral in the wash liquor.2