SURFACE POTENTIALS OF ADSORBED ORGANIC MONOLAYERS ON METALS.

Abstract

Surface potential measurements were accomplished to determine the effects of adsorbed organic monolayers on metal substrates. This data was used to characterize the monolayers as to their orientation, packing and polarization on metals. The vibrating condenser method was used to make surface potential measurements. The method is based on the principle of changing the capacity of a condenser formed by a reference electrode (Pt) and the metal to be studied. Any changes occurring on the metal will be detected by a potential change. Results obtained in this study were that (a) monolayers of acids, alcohols and amines absorbed on chrome cause an increase in the surface potential with an increase in carbon chain length; (b) oil solutions containing additives gave surface potentials in the order: octadecylamine > stearamide > stearic acid > octadecanol, and (c) temperature of wetting curves for the amines and amides correlated with surface potential curves. Conclusions derived were that (a) when alcohols, acids and amines of a sufficient chain length are adsorbed on chrome they form a close-packed oriented monolayer; (b) the tendency of adsorption from an oil solution onto steel depends on the type of additive used; and (c) amides with carbon chain lengths less than 16 have a higher energy of adsorption than the corresponding amines. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1967
Accession Number
AD0658058

Entities

People

  • Peter Martin Jr.

Tags

DTIC Thesaurus Topics

  • Additives (Chemicals)
  • Adsorption
  • Electrodes
  • Fatty Acids
  • Measurement
  • Monomolecular Films
  • Orientation (Direction)
  • Polarization
  • Stearic Acid
  • Substrates

Fields of Study

  • Chemistry

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Materials Science and Engineering.
  • Organic Chemistry