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Influence of ion transfer kinetics on the composition of langmuir-blodgett films

V I Kovalchuk1, M P Bondarenko, E K Zholkovskiy

  • 1Institute of Biocolloid Chemistry, 03142, Kiev, Ukraine, and Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam/Golm, Germany.

The Journal of Physical Chemistry. B
|August 19, 2008
PubMed

The effect of ion transfer kinetics on the ionic composition of Langmuir-Blodgett (LB) films formed by charged monolayers is analyzed. The dynamic regimes of the LB deposition are considered by taking into account the competitive adsorption of several counterions having different diffusivities, valences, binding constants, and bulk concentrations. It is shown that the composition of deposited films should change with the deposition rate. At lower deposition rates, the ion with higher binding constant is more represented within the deposited monolayer in comparison to the higher deposition rates. At low deposition rates, the ratio of counterion amounts within the LB films is the same as that within the floating monolayer excluding the ions within the diffuse layer. At high deposition rates, the ratio of the counterion amounts is the same as that within the floating monolayer when the potential-determining counterions within the diffuse layer are taken into account.

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