Ion redistribution and meniscus stability at Langmuir monolayer deposition

Adv Colloid Interface Sci. 2005 Jun 30:114-115:267-79. doi: 10.1016/j.cis.2004.08.008. Epub 2005 Mar 5.

Abstract

Considering the deposition of charged Langmuir monolayers, it is necessary to take into account electrostatic interactions between the monolayer and the substrate surface. These interactions depend on the nature of ionizable surface groups and on the ionic composition of the subphase (e.g. pH, multivalent counterions, indifferent electrolytes). The non-uniformity of electric, concentration and hydrodynamic velocity fields leads to the formation of ion concentration profiles near the three-phase contact line during the deposition. This effect is similar to the effect of concentration polarization in membranes and electrode systems. The ions redistribution results in change of the monolayer ionization, adhesion work, dynamic contact angle, and, therefore, in the change of morphology, composition and structure of the deposited monolayer. With increasing withdrawal velocity the meniscus can become unstable because of concentration polarization in the solution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biophysics / methods*
  • Electrodes
  • Electrolytes
  • Hydrogen-Ion Concentration
  • Ions
  • Macromolecular Substances / chemistry
  • Models, Statistical
  • Static Electricity
  • Surface Properties*

Substances

  • Electrolytes
  • Ions
  • Macromolecular Substances