Iodide adsorption

Nal concentration, up to 1 X 10 They also obtained steady-state data using a potential step method. The applied potential was initially set at -0.9 V, where no iodide absorption occurs. The electrode was stepped to various positive potentials and A/(ad) was recorded until equilibrium values were obtained. Similar measurements were done in an electrolyte without Nal, and A/(no-ad) was recorded as a reference. The net change in frequency was determined as IAA/I = A/(ad) -A/(no-ad). Figure 27.22 shows I AA/I vs. E plots for various Nal concentrations. Analysis of the data showed that iodide adsorption occurred in accordance with the Temkin isotherm. 

We have previously employed such techniques in the study of iodide adsorption onto Pt(lll) electrodes (2 5 > as well as in the in-situ structural characterization of underpotentially deposited copper and silver on Au(lll) electrodes. (23.)... 

Silver Zeolite Iodide Adsorption Studies. The U.S. Atomic Energy Commission, Idaho Operations Office, Under Contract AT(10-1)-1230, Nov. 

Key Words Pulsed low electric fields Endocytosis Uptake kinetics Membrane internalization Albumin Lucifer Yellow Propidium iodide Adsorption Flow cytometry Confocal microscopy. 

Figure 3. Plots of Om vs. /s at constant potential for iodide adsorption on Ag(l 11) from KPF solutions. Numbers on each curve denote potential values in V/SCE. (Reprinted from Ref.7 with permission from the Am. Chem. Soc.)...

Adsorption of iodine by starch was quantitatively analyzed by Harrison23 as well as by Angulescu and Mirescu.33 Both studies entailed the use of I2 in solutions of potassium iodide. Adsorption took place according to the Freundlich isotherm ... 

Allergic reactions should be treated appropriately with supportive care, maintenance of airway, breathing, and circulation, and antihistamines plus steroids as needed. Discontinue potassium iodide administration and provide symptomatic and supportive care. The extent of iodide adsorption to activated charcoal has not been determined. Plasma iodide levels do not guide therapy the potassium level should be checked. 

Figure 40. C(E) curves for iodide adsorption on gold faces distributed on the three main zones of the projected unit stereographic triangle (concentration = 100 mM KI, frequency = 80 Hz, and sweep rate = 3mVs" ) (a) (lll)-(llO) zone (b) (Ill)-(IOO) zone (c) from (110) to (210) on the (lOO)-(llO) zone and (d) from (210) to (100) on the (lOO)-(llO) zone. ...

The case of iodide adsorption on gold can be fruitfully compared to that of lead adsorption on gold faces which takes place with complete charge transfer, i.e., by so-called underpotential deposition (UPD). 

On the Pd(lll) single crystal, iodide adsorption leads the ( /3 x y/3) R30° I superlattice at potentials lower than 0.80 V at pH =10, whereas on Pd(100), a c(2 x 2) I superlattice is found [111]. Copper underpotential deposition on noble metals is a relatively slow process, and the electrochemical response is strongly dependent on the potentiodynamic perturbation, because of... 

Spohr [190] studied the adsorption of on the Pt(lOO) surface. The free energy barrier towards iodide adsorption that is produced by the layers of adsorbed water is associated with a significant intermediate increase in coordination number, before the hydration number decreases at short ion-metal distances for geometrical reasons. Philpott and Glosli [109] observed in a series of MD studies of ion adsorption on charged electrodes that the Li+ hydration shell structure in the vicinity of a model metal surface does not depend on the halide counterion (F, Cl , Br , I ). In this study, no specific interactions between the metal surface and water molecules or ions were employed. 

Figure 37 shows the formal charge of 1 as a fimction of distance from a Ptg cluster, obtained by Mulliken population analysis of ab initio calculations of Pt9l clusters [115, 239]. The effect of solvation on the partial charge of the hydrated iodide ion near the Pt(lOO) surface was investigated [234] by a combination of quantum chemical calculations, the Anderson-Newns model of chemisorption and MD calculations of the free energy of iodide adsorption [190]. On the basis of the approximations discussed in Ref. 234, the charge on the bare ion can also be calculated from the relation... 

Various types of adsorption isotherms were proposed for ionic adsorption. Parsons (56) found that, at constant charge, only isotherms based on certain types of equations of state satisfactorily apply to iodide adsorption. 

General overviews of STM studies of metal electrodes have been provided [10, 23-25] in addition, an extensive review that focused on ordered anion monolayers on metal electrode surfaces has been published [26]. Charge-induced surface phase transitions on ordered Au(lll) caused by increasing iodide adsorption from an aqueous electrolyte solutions have been observed [27]. The formation of copper sulflde nanostripe patterns on a Au(lll) electrode surface formed by exposure of a single copper monolayer on this electrode and exposed to bisulfide ions in the electrolyte solution has been studied with in situ STM [28]. Correlations between... 

This consideration gives an explanation of the existence of surface-inactive ions for which the attractive contribution due to the short-range (electron exchange) metal surface-ion interaction is absent or insufficiently strong to compensate the aforementioned repulsive effect. It may also be responsible for the strong influence of the iodide adsorption on the hydrogen evolution, despite the absence of marked specific adsorption of H3O+ ions [260]. 

Fig. 22 Experimental values of the repulsion constant , u, in isotherm (93) for iodide adsorption at Bi-water interface (points are shown with their dispersion) as a function of the eiectrode potentiai in the rational scale, (p = E — Eo=o- The theoretical curve (solid line) was calculated from Eq. (92) for A = 0.71 with the use of experimental data for the compact- and diffuse-layer capacitances of the same interface in a surface-inactive electrolyte solution.

In particular, such an effect is observed for the case of iodide adsorption at silver[146]. Hence a somewhat lower energy for the Ag-H bond may be expected for the chloride anions which have a higher adsorbability than the sulfate ions. 

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