title: Effect of the spacer length on the association and adsorption behavior of dissymmetric gemini surfactants.
abstract: A series of dissymmetric gemini surfactants with the general formula [C12H25(CH3)2N(CH2)sN(CH3)2C14H29]Br2 designed as 12-s-14, where s=2, 6, and 10, were synthesized and their physicochemical properties investigated. The effect of spacer length on Krafft temperature, adsorption at the air/solution interface, and association in aqueous solution was studied by tensiometry, conductometry, and cryo-transmission electron microscopy. The Krafft temperature was found to increase linearly with spacer length. In the submicellar concentration range the dissymmetric 12-s-14 surfactants display ion pairing and premicellar association. Adsorption at air/solution interfaces and micellization in aqueous solution are similar to the behavior of their symmetric counterparts and depend strongly on spacer length.
authors.affiliation: Department of Physical Chemistry, Ruder Bosković Institute, Zagreb, Croatia.
authors.forename: M
authors.initials: M
authors.lastname: Sikirić
authors.forename: I
authors.initials: I
authors.lastname: Primozic
authors.forename: Y
authors.initials: Y
authors.lastname: Talmon
authors.forename: N
authors.initials: N
authors.lastname: Filipović-Vinceković