Direct observation of charge inversion by multivalent ions as a universal electrostatic phenomenon.
We have directly observed reversal of the polarity of charged surfaces in water upon the addition of trivalent and quadrivalent ions using atomic force microscopy. The bulk concentration of multivalent ions at which charge inversion reversibly occurs depends only very weakly on the chemical composition, surface structure, size, and lipophilicity of the ions, but is very sensitive to their valence. These results support the theoretical proposal that spatial correlations between ions are the driving mechanism behind charge inversion.
Besteman
K
K
Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands.
Zevenbergen
M A G
MA
Heering
H A
HA
Lemay
S G
SG
D003035:Cobalt / Q000737:chemistry; D003486:Cyanides / Q000737:chemistry; D005292:Ferricyanides / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D058085:Iron Compounds / Q000737:chemistry; D028581:Lanthanoid Series Elements / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009942:Organometallic Compounds / Q000737:chemistry; D011107:Polylysine / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D055672:Static Electricity
D003486:Cyanides; D005292:Ferricyanides; D005296:Ferrous Compounds; D007477:Ions; D058085:Iron Compounds; D028581:Lanthanoid Series Elements; D008670:Metals; D009942:Organometallic Compounds; C007931:hexacyanoferrate III; D011107:Polylysine; D003035:Cobalt; D012822:Silicon Dioxide