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Electric Field Measurements inside Self‐Assembled Multilayer Films at Electrode Surfaces by Electrochemically Modulated Surface Plasmon Resonance Experiments
Author(s) -
Hanken Dennis G.,
Corn Robert M.
Publication year - 1997
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.199700020
Subject(s) - chemistry , electric field , surface plasmon resonance , electrode , analytical chemistry (journal) , penetration depth , electrochemistry , bromide , polarization (electrochemistry) , optics , nanotechnology , inorganic chemistry , materials science , nanoparticle , organic chemistry , physics , quantum mechanics
The new in situ optical technique of electrochemically modulated surface plasmon resonance (EM‐SPR) is described and applied to the measurement of the electrostatic fields inside noncentrosymmetric zirconium phosphonate (ZP) films formed from the asymmetric nonlinear optical material [1‐[4‐[4‐[( N ‐(2‐hydroxyethyl)‐ N ‐methyl)amino]phenyl]azo](5‐phosphonopentyl)] pyridinium bromide (PY‐AZO). In situ EM‐SPR measurements on PY‐AZO films yield a value for the change in electric field strength (Δ E ) of 4 × 10 3 V/cm for a change in electrode potential (Δϕ m ) at 0.0 V vs. SCE of ±25 mV (8 × 10 4 V/cm for Δϕ m = 1 V). This electric field strength value indicates that there is substantial ion penetration into the film in the electrochemical environment. Both the phase and magnitude of the surface optical response in the EM‐SPR measurements are used to distinguish the molecular and metal electrode contributions to the overall optical signal. These two EM‐SPR contributions are identified and separated in a quantitative fashion through a series of theoretical Fresnel calculations.