Measuring the activation energy of thiol desorption using lateral force microscopy

Scanning. 2012 May-Jun;34(3):200-5. doi: 10.1002/sca.20293. Epub 2011 Oct 21.

Abstract

Thermal stability of self-assembled monolayers (SAMs) is important for applications in various surface science applications. As a model material, 16-mercaptohexadecanoic acid (MHA) on template stripped gold surfaces was investigated to determine the effect of temperature on the change of lateral force signal using atomic force microscopy (AFM). Friction force signals were obtained at various temperatures in order to determine whether it was possible to correlate the friction signal with desorption of the thiol molecule from the surface. Samples were heated for up to 10 h ranging from 40 to 80 °C in air and scanned every hour. A kinetic model was introduced to correlate the lateral force signal to the activation energy of desorption of the SAM from gold surface with heating. The activation energy of the detachment using this technique is 25.4 kcal/mol, which is consistent with other more complex techniques.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Friction
  • Gold / chemistry
  • Kinetics
  • Microscopy, Atomic Force / methods*
  • Molecular Structure
  • Palmitic Acids / chemistry*
  • Sulfhydryl Compounds / chemistry*
  • Surface Properties
  • Temperature
  • Time Factors

Substances

  • 16-mercaptohexadecanoic acid
  • Palmitic Acids
  • Sulfhydryl Compounds
  • Gold