tetradecyltrimethylammonium

Tetradecyltrimethylammonium refers to the quaternary ammonium cation [N+(CH3)3(C14H29)], consisting of a tetradecyl (C14) hydrocarbon tail attached to a positively charged nitrogen that bears three methyl groups. In practice it is encountered as salts such as tetradecyltrimethylammonium chloride or tetradecyltrimethylammonium bromide, where the counteranion balances the charge.

As a cationic surfactant, the molecule is amphiphilic: a hydrophobic tail and a charged, hydrophilic head. This arrangement gives surface-active properties and the ability to form micelles in aqueous solution. The critical micelle concentration (CMC) and related characteristics depend on the counterion and temperature; generally, longer alkyl chains lower the CMC to some extent, while the specific anion can influence solubility and aggregation behavior.

Applications include use as a surfactant and conditioning agent in personal care products, cleaners, and textile formulations. The cationic head can confer antimicrobial activity in some formulations and it may be employed as a preservative component or functional additive where surface properties are important.

Safety and environmental considerations follow those of many quaternary ammonium salts. They can be irritants to skin and eyes, and they are typically used at concentrations chosen to balance performance with safety. Environmental concerns include potential aquatic toxicity, and disposal should follow applicable regulations for quats.

Synthesis generally involves quaternization of a tertiary amine precursor, for example N,N-dimethyl-tetradecylamine, with a methylating agent such as methyl halide to yield the tetradecyltrimethylammonium salt. See also related long-chain alkyltrimethylammonium surfactants.