Inhomogeneous electrodes—a polarization model of the partially blocked reversible metal ion electrode

Schmidt, Eberhard; Hitzig, J.; Titz, J.; Jüttner, K.; Lorenz, W.J.

doi:10.1016/0013-4686(86)80019-6

Cited by 56 publications

(23 citation statements)

References 13 publications

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“…First, the Nyquist and Bode plots are almost always ideal, as predicted, because they represent the snapshots of impedance during a short period of the experiment. This situation is rather unusual because the impedance signals acquired by other techniques are hardly ideal (32,(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51), perhaps because the impedance obtained by the FRA is the time-averaged signal over the period of the measurement. Even for a complex system, such as aniline oxidation leading to the formation of polyaniline, nearly ideal semicircles are observed (52).…”

Section: Measuring Impedancementioning

confidence: 99%

Peer Reviewed: Electrochemical Impedance Spectroscopy for Better Electrochemical Measurements

Park¹,

Yoo²

2003

Anal. Chem.

379

150

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Section: Measuring Impedancementioning

confidence: 99%

Peer Reviewed: Electrochemical Impedance Spectroscopy for Better Electrochemical Measurements

Park¹,

Yoo²

2003

Anal. Chem.

379

150

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“…Living polymerization techniques are indispensable tools for the preparation of macromolecules with controlled architectures. [1][2][3][4] The discovery of living anionic olefin polymerization a half century ago 5,6 led to a burgeoning field of research and has enabled the construction of complex macromolecules (block copolymers, star polymers, hyperbranched polymers, comb polymers). 1 Detailed kinetic investigations of CdC bond polymerizations, particularly with styrene, allowed for the determination of activation parameters for propagation.…”

Section: Introductionmentioning

confidence: 99%

Studying a Slow Polymerization: A Kinetic Investigation of the Living Anionic Polymerization of PC Bonds

Noonan

Gates

2008

Macromolecules

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The n-butyllithium-initiated living anionic polymerization of MesPdCPh 2 (Mes ) 2,4,6trimethylphenyl) was studied at a variety of temperatures (T ) 296. 3, 301.8, 307.4, 313.0, 318.6, and 324.2 K) with a fixed monomer-to-initiator ratio (50:1). The consumption of monomer and formation of polymer n Bu[MesP-CPh 2 ] n Li was monitored by 31 P NMR spectroscopy, and the conversion data obtained were analyzed using first-order kinetics. Up to 50% conversion, the plot of ln [M] 0 /[M] vs time was linear, and apparent propagation rate constants (k p ) were extracted (k p ) 21-150 L mol -1 h -1 , T ) 296-324 K). These rate constants were used to construct an Arrhenius plot, and the apparent activation energy for the propagation of PdC bonds was estimated (E a ) 14.0 ( 0.9 kcal mol -1 ).

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“…The respective solvating powers of TRIG and DOX toward cations are illustrated by the early results M. Szwarc’s group obtained with the lithium cation, which were recently rediscussed by J. Smid et al For the fluorenyl lithium in DOX at 25 °C, the observed fraction of solvent-separated ion pairs does not exceed 2%, but the addition of a small amount of TRIG (∼10 −2 mol L −1 ) in DOX increases this fraction up to 50%. Similar solvation ability is expected with respect to the proton, the TRIG replacing the water of the hydroxonium and shifting the equilibrium toward the solvated species.…”

Section: Resultsmentioning

confidence: 94%

Cationic Copolymerization of 1,3,5-Trioxane with 1,3-Dioxepane: A Comprehensive Approach to the Polyacetal Process

et al. 2009

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The bulk copolymerization of 1,3,5-trioxane (TOX) with 1,3-dioxepane (DXP) initiated by perchloric acid hydrate(s) is studied at 80 °C with DXP/TOX initial ratios from 20/80 to 3/97 w/w. As usually observed for the polyacetal synthesis, the polymerization takes place within seconds to tenths of seconds and proceeds in two steps, a homogeneous (“induction”) period, followed by a very rapid heterogeneous propagation−crystallization step. The influence of the reaction conditions was systematically examined (diluent of initiator, comonomer concentration, transfer to residual water), and the products formed during the short induction period were identified using NMR. The difference between the respective basicities of the comonomers is such that during the induction period the initiation takes place on the DXP, and for DXP initial concentrations above its equilibrium value [DXP]eq,ss the early formed soluble polymer is either the homopolymer or a DXP highly enriched copolymer. The precipitation step starts only after the concentration of DXP is lowered enough to allow the copolymerization with TOX to proceed significantly and the poly(oxymethylene) −[CH2−O] n − sequences to reach their critical crystallization length. This critical concentration was found constant whatever the initial DXP/TOX ratio. For initial concentrations lower than [DXP]eq,ss (i.e., DXP/TOX ≤ 5/95 w/w), the DXP cannot homopolymerize and should be consumed by single unit insertion during a copolymerization effective since the early beginning. Therefore, during the further heterogeneous propagation−crystallization step, the insertion of two successive DXP units in the copolymer chain becomes highly improbable. The copolymer formed by both propagation and transacetalization processes is either inserted into the crystal (or its immediate interface) if only isolated DXP units are present along the poly(oxymethylene) chain or rejected in the amorphous phase if preformed DXP sequences are present. The latter situation occurs for DXP/TOX initial ratios ≥10/90 w/w. This is in agreement with our previous measurements of the crystal partitioning coefficient, which confirmed that the tetramethyleneoxy −[(CH2)4−O]− units from DXP are progressively rejected into the increasing amorphous fraction for initial DXP richer compositions. Coherent chemical pathways are proposed for the overall process, which are in accordance with the experimental behaviors during both homogeneous and heterogeneous steps.

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Inhomogeneous electrodes—a polarization model of the partially blocked reversible metal ion electrode

Cited by 56 publications

References 13 publications

Peer Reviewed: Electrochemical Impedance Spectroscopy for Better Electrochemical Measurements

Peer Reviewed: Electrochemical Impedance Spectroscopy for Better Electrochemical Measurements

Studying a Slow Polymerization: A Kinetic Investigation of the Living Anionic Polymerization of PC Bonds

Cationic Copolymerization of 1,3,5-Trioxane with 1,3-Dioxepane: A Comprehensive Approach to the Polyacetal Process

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