title: Charge inversion at high ionic strength studied by streaming currents.
abstract: We report charge inversion, the sign reversal of the effective surface charge in the presence of multivalent counterions, for the biologically relevant regimes of divalent ions and mixtures of monovalent and multivalent ions. Using streaming currents, the pressure-driven transport of countercharges in the diffuse layer, we find that charge inversion occurs in rectangular silica nanochannels at high concentrations of divalent ions. Strong monovalent screening is found to cancel charge inversion, restoring the original surface charge polarity. An analytical model based on ion correlations successfully describes our observations.
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Frank H J
authors.initials: FH
authors.lastname: van der Heyden
authors.forename: Derek
authors.initials: D
authors.lastname: Stein
authors.forename: Koen
authors.initials: K
authors.lastname: Besteman
authors.forename: Serge G
authors.initials: SG
authors.lastname: Lemay
authors.forename: Cees
authors.initials: C
authors.lastname: Dekker
mesh_terms: D007473:Ion Channels / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D009994:Osmolar Concentration; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D007473:Ion Channels; D007477:Ions; D012822:Silicon Dioxide