Quaternary ammonium compounds, also known as quats, consist of a positively charged nitrogen atom with four substituents, carbon groups. Substituents covalently bound to the nitrogen atom may be aliphatic, aromatic or mixed. Another name for this group is quaternary ammonium salts. These compounds belong to the group of cationic surfactants.

How are quaternary compounds formed?

Quaternary ammonium cations are permanently charged, regardless of the pH of their solution. They are prepared by the alkylation of tertiary amines (quaternization). The most widely used method of obtaining quaternary ammonium compounds is the methylation of amino groups with methyl chloride or benzyl. Most ammonium salts are resistant to strong electrophiles, oxidants and acids.

Properties and use of quaternary compounds

Quaternary ammonium salts have antimicrobial activity, which is why they are used in disinfectant and antiseptic preparations. Due to the presence of positively charged nitrogen in the structure and long carbon chains, these compounds are effective anti-electrostatic agents. These properties are used in the textile industry for conditioning of materials and in the production of plastics. In addition, quaternary ammonium compounds are characterized by metal adsorption capacity, which confers anti-corrosion properties.

Quaternary compounds are widely used as surface disinfectants in healthcare, hospitality and many other industries, due to the ability to eliminate a wide spectrum of bacteria and fungi. They have also found application in the metallurgical industry as corrosion inhibitors, in the production of plastics and CASE. The possibility of designing various structures of quaternary compounds causes that they are also used as specialist products in narrow sectors of industries.