Lauryldimethylamine oxide (LDAO), also known as dodecyldimethylamine oxide (DDAO), is an
amine oxide
In chemistry, an amine oxide, also known as an amine ''N''-oxide or simply ''N''-oxide, is a chemical compound that contains the functional group , a nitrogen-oxygen coordinate covalent bond with three additional hydrogen and/or substituent-grou ...
based
zwitterionic surfactant, with a C
12 (dodecyl) alkyl tail. It is one of the most frequently-used surfactants of this type. Like other amine oxide based surfactants it is
antimicrobial
An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ar ...
, being effective against common bacteria such as ''
S. aureus'' and ''
E. coli'',
however it is also non-denaturing and may be used to solubilize proteins.
At high concentrations, LDAO forms
liquid crystalline phases. Despite having only one polar atom that is able to interact with water – the oxygen atom (the
quaternary nitrogen atom is hidden from intermolecular interactions), DDAO is a strongly amphiphilic surfactant: it forms normal
micelle
A micelle () or micella () (plural micelles or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated coll ...
s and normal liquid crystalline phases. High amphiphilicity of this surfactant can be explained by the fact that it forms not only very strong hydrogen bonds with water: the energy of DDAO – water hydrogen bond is about 50 kJ/mol, but it also has high experimental partition coefficient in non-polar medium, as characterized by experimental logP 5.284
See also
*
Myristamine oxide – An analogous compound with a C
14 tail
References
{{reflist
Amine oxides
Surfactants