title: Disjoining pressure of discrete surface charges on thin aqueous films.
abstract: The disjoining pressure of charged parallel interfaces confining an electrolyte solution is to a large extent determined by the screening clouds of the surface charges. We evaluate the pressure in terms of the number density sigma of discrete charges and film thickness d and find, at sigmad(2) approximately 1, a crossover from the well-known law P approximately sigma(2) to a linear behavior P approximately sigma. For the latter case, each surface charge results in strongly inhomogeneous pressure profiles at both interfaces.
mesh_terms: D001703:Biophysics / Q000379:methods; D002412:Cations / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry; D008956:Models, Chemical; D011312:Pressure; D012996:Solutions; D055672:Static Electricity; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D002412:Cations; D004573:Electrolytes; D012996:Solutions; D014867:Water