Adsorption of cyclohexanone and its effect on the polarographic reduction of different ions

Abstract

As a contribution towards the effect of adsorption on electrode kinetics, the adsorption of cyclohexanone and its effect on the polarographic reduction of different ions have been investigated. In Chapter 1 of the thesis, a brief introduction to adsorption effects in general has been presented. Usually, surfactants by their adsorption influence the rate of an electrode process resulting in either an inhibition or less frequently an acceleration of the electrode reactions under investigation. Adsorption can also affect the mass transport steps, sometimes giving rise to the polarographic maxima and sometimes their suppression. The theory based on the earlier pioneering work by Frumkin and Levich is rederived in Chapter 2. This treatment is then extended to present a unified theory of polarographic maxima. Chapter 3 deals with the experimental techniques adopted in this work for the study of adsorption of cyclohexanone and its effect on the polarographic reduction of different depolarisers. In Chapter 4, results obtained during the adsorption studies with cyclohexanone and its influence on the polarographic reduction of various depolarisers are presented. Polarographic maxima of a new kind are observed in the presence of cyclohexanone in solution. The important characteristics of these maxima are outlined along with a tentative mechanism for the same. In Chapter 5, theories for the polarographic maxima of the third and the fourth kinds are presented. An equation for estimating the tangential velocity has also been derived for these types of polarographic maxima. Chapter 6 deals with the results as well as a brief discussion on the inhibition effects observed for the electroreduction of cadmium ions in presence of cyclohexanone in solution. Chapter 7 includes a summary of the main points emerging from the present work and some suggestions regarding future work.