ISSN:
1040-0397
Keywords:
Methyl viologen
;
Pyrex glass
;
Adsorption
;
Nafion
;
Renewable electrode
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Square wave voltammograms of methyl viologen (MV2+) were recorded at a renewable Nafion-loaded carbon paste electrode immersed in 20 mL of phosphate buffer solution (pH 7.4) contained in a beaker-type electrochemical cell (Pyrex glass; contact area = 33 cm2). From the calibration plot obtained in the concentration range 0.01-2.4 μM, it could be concluded that the maximum surface excess of MV2+ adsorbed on Pyrex glass (0.24 nmol cm-2) was reached at concentrations above 1.4 μM. The adsorption isotherm presented a sigmoidal shape characteristic of attractive interaction. From this plot, it was evaluated that the maximum depletion of MV2+ in solution (28%) did not occur at the lowest concentrations, but in nearly micromolar solutions. This result emphasizes the unavoidable and random errors which are involved when MV2+ solutions are purposely diluted in Pyrex glassware. The MV2+ adsorption proceeds to a less extent on Duran borosilicate glass and/or in acid or alkaline medium.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140090505
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