8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Wed 711:10-14:00P5.141Two-particle double layer interaction in confinedgeometriesEmilio Ruiz-Reina 1 and Félix Carrique 21 Department of Applied Physics II, University of Málaga, Escuela de Ingenierías,Campus de Teatinos, s/n, 29071, Málaga, Spain2 Department of Applied Physics I, University of Málaga, Málaga, SpainIn this work we have developed a numerical study, based on the finite element method, for thecalculation of the ionic an electric potential distributions around two interacting colloidal particlesin a capillary-type confined geometry. The full non-linear Poisson-Boltzmann equation is solvedand, by changing the particles separating distance, we can obtain the interaction potential [1]from the solutions. In this way, we can analyze the influence of the confinement in the interactionpotential. Our model system consists of two equal charged spherical particles inmersed in asalt-free medium (which only contains the so-called ”added counterions” stemming from theparticles charging mechanism) enclosed in a narrow capillary with a size comparable with theradius of the particles. The use of this numerical technique allows us to deal with the lackof spherical symmetry of the present problem. The utilization of the finite element method isrelatively new in this area, but there are some groups that have already worked in the subject [2].Acknowledgements: Junta de Andalucía, Spain (Project P08-FQM-3779) and MICINN, Spain(Project FIS2010-18972), co-financed with FEDER funds by the EU.[1] Ohshima, H. , Theory of Colloid and Interfacial Electric Phenomena, in Interface Scienceand Technology, 12, Academic Press, Elsevier Ltd. , The Netherlands, 2006.[2] Masliyah, J. H. ; Bhattacharjee, S. , Electrokinetic and Colloid Transport Phenomena, NewJersey, John Wiley, 2006.141