Interactions and self assembly of two heterogeneously charged surfaces

Recent experiments$^{1,2}$ have measured attractive interactions between two surfaces that each bear two molecular species with opposite charge. Theoretical considerations predict equilibrium finite-sized domains of each species, consistent with experiment. These domains, whose observed sizes are typically tens of nanometers, are the result of a balance between the line tension, which prefers macroscopic separation, and the electrostatics, which prefers mixing. Additionally, two such surfaces show a long range attraction. We present a theoretical model that predicts the domain size, phase behavior and forces for two such interacting surfaces. \\* \\* (1) E. E. Meyer, Q. Lin, T. Hassenkam, E. Oroudjev, J. N. Israelachvili PNAS {\bf 102}, 6839 (2005). \\* (2) S. Perkin, N. Kampf, J. Klein, Phys. Rev. Lett. {\bf 96}, 038301 (2006).