Interfacial water dielectric-permittivity-profile measurements using atomic force microscopy

Phys Rev E Stat Nonlin Soft Matter Phys. 2001 Jul;64(1 Pt 1):011605. doi: 10.1103/PhysRevE.64.011605. Epub 2001 Jun 27.

Abstract

The arrangement of water molecules at charged aqueous interfaces is an important question in biology, electrochemistry, and geochemistry. Theoretical studies suggest that the molecules become arranged in several layers adjacent to a solid interface. Using atomic force microscopy we have measured the water dielectric-permittivity profile perpendicular to mica surfaces. The measured variable permittivity profile starting at epsilon approximately 4 at the interface and increasing to epsilon=80 about 10 nm from the surface suggests a reorientation of water molecule dipoles in the presence of the mica interfacial charge.

MeSH terms

  • Aluminum Silicates*
  • Biophysical Phenomena
  • Biophysics*
  • Microscopy, Atomic Force / methods*
  • Models, Theoretical
  • Silicon / chemistry
  • Surface Properties
  • Water / chemistry*

Substances

  • Aluminum Silicates
  • Water
  • mica
  • Silicon