Interaction between poly(vinylimidazole) and sodium dodecyl sulfate: Binding and adsorption properties at the silica/water interface

• Published in: Journal of colloid and interface science Vol. 274; no. 2; pp. 421 - 432
• Main Authors: Roques-Carmes, T., Aouadj, S., Filiâtre, C., Membrey, F., Foissy, A.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.06.2004; Elsevier
• Subjects: Adsorption kinetics; Cationic polyelectrolyte-anionic surfactant mixture; Chemistry; Exact sciences and technology; General and physical chemistry; Poly(vinylimidazole) (PVI); PVI/SDS complex; Reflectometry; Silica/water interface; Simultaneous adsorption; Sodium dodecyl sulfate (SDS); Surface physical chemistry; PVI/SDS complex; Sodium dodecyl sulfate (SDS); Reflectometry; Simultaneous adsorption; Adsorption kinetics; Silica/water interface; Poly(vinylimidazole) (PVI); Cationic polyelectrolyte-anionic surfactant mixture; Water; Binding; Ionic surfactant; Complexes; Silica; Lauryl sulfate; Polyelectrolyte; Anionic surfactant; Adsorption; Sodium; Imidazole(vinyl) polymer; Kinetics; Interface
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2004.01.057

The adsorption properties (adsorbed amount, kinetics, and reversibility) of poly(vinylimidazole) (PVI) and sodium dodecyl sulfate from PVI/SDS mixed solutions on negatively charged silica substrates were studied at pH 9 using reflectometry and compared to that measured on colloidal silica by the solution depletion method. In this paper, we will try to gain insight into the effect of PVI/SDS complex composition on the adsorption characteristics of the complex and particularly on the kinetics of the complex adsorption and its consequence on the adsorption reversibility. The properties of the complex in solution were characterized by means of potentiometric titration at a constant pH, binding isotherm, and surface tension measurements. On the basis of the experimental results the prevailing mechanism of the SDS/PVI interaction and the properties of the PVI/SDS complex were evaluated. Both the PVI/SDS complex uptake and the kinetics of the adsorption decreased with the amount of SDS bound to PVI. At low PVI/SDS binding ([SDS] 0<critical aggregation concentration CAC), the complex adsorption is transport limited while at high binding ([SDS] 0>CAC) the incoming complex experiences a blocking barrier of an electrostatic nature. This barrier has been confirmed by reversibility measurement, and the respective roles of the complex structure and charge were assessed.