Accession Number : ADA301975

Title :   Measurements of the Potential Dependence of Electric Field Magnitudes at an Electrode Surface Using Fluorescent Probes in a Self-Assembled Monolayer.

Descriptive Note : Technical rept. Jun 94-May 95,

Corporate Author : WYOMING UNIV LARAMIE DEPT OF CHEMISTRY

Personal Author(s) : Pope, John ; Buttry, Daniel

PDF Url : ADA301975

Report Date : 29 JUL 1995

Pagination or Media Count : 34

Abstract : This report details the measurement of the dependence of the electric field magnitude on applied potential in two regions of the electrical double layer, inside the Outer Helmholtz Plane (OHP), i.e. inside the monolayer, and in the diffuse layer, for a metal/organic thin film/electrolyte system. The self-assembled monolayers (SAM's) used in these experiments were formed from n-alkyl thiols on roughened Ag and roughened or smooth Au electrodes. The electric field magnitudes were calculated from the Stark shifts of a cationic fluorescent probe, an (aminostyryl)pyridinium derivative, that was immobilized in the SAM. The chain lengths of these alkyl thiols were varied to control the distance of the probe from the OHP and thus the relative position of the probe in the electrical double layer. Two cases were examined, one in which the probe was embedded within the SAM, and another in which the probe was external to the SAM. The composition of the monolayers and the orientation of the probe and n-alkyl thiol molecules within them were characterized using ex situ reflection-absorption Fourier transform infrared spectroscopy (RA-FTIR). jg p3

Descriptors :   *FLUORESCENCE, *ELECTRIC FIELDS, *SURFACES, *ELECTRODES, *ELECTRIC DOUBLE LAYER, FOURIER TRANSFORMATION, METALS, CATIONS, POSITION(LOCATION), PROBES, INFRARED SPECTROSCOPY, LAYERS, THIN FILMS, ORIENTATION(DIRECTION), LENGTH, CHAINS, SHIFTING, ORGANIC COMPOUNDS, EXTERNAL, DIFFUSION, ELECTROLYTES, RANGE(DISTANCE), GOLD, STARK EFFECT, SILVER, ALKYL RADICALS, THIOLS.

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Electricity and Magnetism
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE