Amphoteric surfactants

As amphoteric surfactants or also as zwitterionic surfactants are called surfactants containing both a negatively and a positively charged functional group possess. Like every surfactant, amphoteric surfactants are also made up of a polar and a non-polar part. An alkyl group serves as the non- polar part, and usually a carboxylate group (R – COO ^- ) together with a quaternary ammonium group (R ₄ N ⁺ ) as the polar part . See also: Structure of surfactants .

Amphoteric surfactants (examples)
Betaines : R = alkyl chain of 5 to 21 carbon atoms. It is named after the natural substance betaine , trimethylammonioacetate. In many shampoos z. B. cocamidopropyl betaine ( coconut fatty acid -amidopropylbetain, "betaine HT") is used as surfactant.
Sultaine : R = alkyl chain. It is a sulfobetaine . Here the anionic group is formed by a sulfonate . An amphoteric compound called taurine (2-aminoethanesulfonic acid) occurs naturally . In shampoos is cocoamidopropyl hydroxy sultaine often used as foam boosters.
Disodium cocoamphodiacetate , an imidazoline derivative .
Amphoacetate , an imidazoline derivative

use

These surfactants are used due to their synergistic properties on the skin compatibility of the anionic surfactants in bath additives for children, hair shampoos and in other cosmetic products, i. H. the skin compatibility of anionic surfactants is significantly improved by adding amphoteric surfactants.

In biochemistry, amphoteric surfactants for solubilisation of proteins used (in particular the sulphobetaines), inter alia in the 2D gel electrophoresis .

Individual evidence

^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, pp. 503-504.
^ ^A ^b Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 742, ISBN 3-342-00280-8 .
↑ L. Vuillard, N. Marret, T. Rabilloud: Enhancing protein solubilization with nondetergent sulfobetaines. In: Electrophoresis. Volume 16, Number 3, March 1995, pp. 295-297, PMID 7607159 .
↑ C. Tastet, S. Charmont, M. Chevallet, S. Luche, T. Rabilloud: Structure-efficiency relationships of zwitterionic detergents as protein solubilizers in two-dimensional electrophoresis. In: Proteomics. Volume 3, Number 2, February 2003, pp. 111-121, doi : 10.1002 / pmic.200390019 , PMID 12601803 .
^ S. Luche, V. Santoni, T. Rabilloud: Evaluation of nonionic and zwitterionic detergents as membrane protein solubilizers in two-dimensional electrophoresis. In: Proteomics. Volume 3, Number 3, March 2003, pp. 249-253, doi : 10.1002 / pmic.200390037 , PMID 12627377 .

[ABC_Chemie-1] Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, pp. 503-504.

[Hauptmann-2] A ^b Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 742, ISBN 3-342-00280-8 .

[3] L. Vuillard, N. Marret, T. Rabilloud: Enhancing protein solubilization with nondetergent sulfobetaines. In: Electrophoresis. Volume 16, Number 3, March 1995, pp. 295-297, PMID 7607159 .

[4] C. Tastet, S. Charmont, M. Chevallet, S. Luche, T. Rabilloud: Structure-efficiency relationships of zwitterionic detergents as protein solubilizers in two-dimensional electrophoresis. In: Proteomics. Volume 3, Number 2, February 2003, pp. 111-121, doi : 10.1002 / pmic.200390019 , PMID 12601803 .

[5] S. Luche, V. Santoni, T. Rabilloud: Evaluation of nonionic and zwitterionic detergents as membrane protein solubilizers in two-dimensional electrophoresis. In: Proteomics. Volume 3, Number 3, March 2003, pp. 249-253, doi : 10.1002 / pmic.200390037 , PMID 12627377 .