Model-Independent Analysis of Pyrene Photokinetics in SDS Micelles

Villegas, Michele M.; Neal, Sharon L.

doi:10.1021/jp970171z

Cited by 15 publications

(26 citation statements)

References 33 publications

(61 reference statements)

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“…The excellent fits of time resolved and steady state data with the same set of parameter values corroborate the validity of the proposed models. Reported SDS excimer formation rates k 1 of 20•10 6 M -1 s -1 are in good agreement with our value [8,55,70,71]. The lifetime of pyrene is quenched by oxygen both in water and within the micelles [72].…”

Section: Time-resolved Fluorescence Intensitysupporting

confidence: 89%

Fluorescence emission of pyrene in surfactant solutions

Piñeiro

Novo

Al‐Soufi

2015

Advances in Colloid and Interface Science

232

139

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The systematic description of the complex photophysical behaviour of pyrene in surfactant solutions in combination with a quantitative model for the surfactant concentrations reproduces with high accuracy the steady-state and the time resolved fluorescence intensity of pyrene in surfactant solutions near the cmc, both in the monomer and in the excimer emission bands. We present concise model equations that can be used for the analysis of the pyrene fluorescence intensity in order to estimate fundamental parameters of the pyrene-surfactant system, such as the binding equilibrium constant K of pyrene to a given surfactant micelle, the rate constant of excimer formation in micelles, and the equilibrium constant of pyrene-surfactant quenching. The values of the binding equilibrium constant K(TX100)=3300·10³ M⁻¹ and K(SDS)=190·10³ M⁻¹ for Triton X-100 (TX100) and SDS micelles, respectively, show that the partition of pyrene between bulk water and micelles cannot be ignored, even at relatively high surfactant concentrations above the cmc. We apply the model to the determination of the cmc from the pyrene fluorescence intensity, especially from the intensity ratio at two vibronic bands in the monomer emission or from the ratio of excimer to monomer emission intensity. We relate the finite width of the transition region below and above the cmc with the observed changes in the pyrene fluorescence in this region.

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Section: Time-resolved Fluorescence Intensitysupporting

confidence: 89%

Fluorescence emission of pyrene in surfactant solutions

Piñeiro

Novo

Al‐Soufi

2015

Advances in Colloid and Interface Science

232

139

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“…Identical well-defined structures, albeit with different coverage, have previously been established for the adsorption of CO from CO-saturated acidic aqueous solutions on Pt(111). By means of in-situ STM, [55] surface X-ray scattering (SXS) [56][57][58] and, more recently, in-situ second harmonic generation and differential reflectance spectroscopy, [59] the (2�2)-3CO and the ð ffi ffi ffi ffi ffi 19 p � ffi ffi ffi ffi ffi 19 p ÞR23:4 � -13CO structure, at low and higher potentials, respectively, have been investigated. [57,60] In addition, evidence from in-situ Fourier transform IR spectroscopy has shown that corresponding spectrum of these structures exhibits bands for on-top and bridge-bonded CO, [61] which also fit to the results presented here in this study.…”

Section: Structure IImentioning

confidence: 99%

Adsorption of Acetate on Au(111): An in‐situ Scanning Tunnelling Microscopy Study and Implications on Formic Acid Electrooxidation

et al. 2019

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The adsorption of acetate on an Au(111) electrode surface in contact with acetic acid at pH 2.7 was imaged in‐situ using scanning tunnelling microscopy (STM). Two different ordered structures were imaged for acetate adsorbed in the bidentate configuration on the unreconstructed ()1×1 surface at 0.95 V (vs. the saturated calomel electrode, SCE). The first structure,(19×19)R23.45∘ , is metastable and transforms at constant potential within 20 minutes to a (2×2) structure, which is thermodynamically more favourable. The (2×2) acetate adlayer starts to form at step edges and propagates via nucleation and growth onto terraces. The findings from in‐situ STM are in agreement with the electrochemical behaviour of acetate on Au(111) characterized by voltammetry. A comparison is made with formate adsorption on Au(111). While acetate is not reactive, in contrast to formate, it can act as a spectator species in formic acid electrooxidation.

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“…Structures of electrosorbed CO layers on Pt(111) were first investigated with electrochemical scanning tunnelling microscopy (STM). [60] In this study, three distinctive CO monolayers were proposed: (2 3 2)-3CO, (19 3 p 19)R23.48-13CO, and ( p 7 3 p 7)R19.18-4CO. The ball models for these three structures are shown as the insets of Figure 5.…”

Section: Electrocatalysismentioning

confidence: 88%

“…In the ex situ studies, the ( p 7 3 p 7) structure was also found finally validating that Villegas and Weaver's STM studies have correctly predicted all three structures. [60] In all of these SXS studies, there was still one remaining puzzle. That was whether the x-ray scattering from CO layer is strong enough to be easily seen in GIXD.…”

Section: Electrocatalysismentioning

confidence: 99%

X‐Ray Scattering and Imaging Studies of Electrode Structure and Dynamics

You

2018

The Chemical Record

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We will review structures and dynamics of electrode interfaces studied in situ using x‐ray scattering and imaging techniques. The examples cover single‐crystal and nanocrystal structures relevant to electrocatalytic activities, anodic oxidation and corrosion, aqueous dissolution reactions, surface reconstructions, and surface modifications by under potential deposition. The x‐ray techniques include the widely used traditional surface x‐ray scattering, such as crystal truncation rods and x‐ray reflectivity, as well as recently developed resonance surface scattering, coherent surface x‐ray photon correlation spectroscopy, coherent x‐ray Bragg diffraction imaging, and surface ptychography. Results relevant to various electrochemical phenomena will be highlighted.

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Model-Independent Analysis of Pyrene Photokinetics in SDS Micelles

Cited by 15 publications

References 33 publications

Fluorescence emission of pyrene in surfactant solutions

Fluorescence emission of pyrene in surfactant solutions

Adsorption of Acetate on Au(111): An in‐situ Scanning Tunnelling Microscopy Study and Implications on Formic Acid Electrooxidation

X‐Ray Scattering and Imaging Studies of Electrode Structure and Dynamics

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