Catanionic Micelles As a Model to Mimic Biological Membranes in the Presence of Anesthetic Alcohols

Abstract

We show here the influence of n-alcs. (C2OH-C8OH) on the soly. behavior of cationic-anionic surfactant mixts., so-called "catanionics". We studied catanionics of different compns. composed of sodium dodecyl sulfate (SDS)/cetyltrimethylammonium bromide (CTAB) and sodium dodecanoate (SDod)/CTAB mixts. Interestingly, with a molar excess of SDS, long chain n-alcs. (C4OH-C8OH) significantly depress the soly. temp. of the SDS + CTAB catanionic and increase the kinetic stability of the soln. The visual observations of soly. temps. of catanionics were further confirmed by differential scanning calorimetry (DSC) measurements. For the catanionics a multistep solubilization was obsd. by DSC, for which the sulfate headgroup is responsible. This was probed by replacing SDS by SDod. A remarkable analogy was found between the influence of the alcs. on the soly. patterns of the catanionic mixts. and on the anesthesia of tadpoles. Possible reasons for this analogy are discussed also in this paper.