Date of Award

1988

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Chemical Engineering

Keywords

Engineering, Chemical.

Rights

CC BY-NC-ND 4.0

Abstract

In order to enhance the reproducibility of the separate sensitization and catalyst technology Sn(II)/Sn(IV)/HCl systems were studied along three main avenues. Kinetic studies. Data for the oxidation of Sn(II) in both concentrated and dilute HCl, Sn(IV) hydration and hydrolysis as well as reaction between Sn(II) and Sn(IV) lead to a model for the ageing of sensitizers. Linear chains of Sn(II)-Sn(IV) go on growing passing through a maximum of surface activity. Adsorption studies. The quantitative effect of: contact time with substrate, surface active agents as additives, HCl concentration, accelerators and inhibitors of Sn(II) oxidation as well as ageing effects on these factors are included to support the model. Transmission electron microscopy. Correlation between the adsorption of sensitizers and the metal deposits they produce indicate that the higher the amount adsorbed, the smaller average metal islands. The nucleation density increases with adsorption exponentially. Crystallite size distributions are narrow and not affected by sensitization. Overgrown colloids in the sensitizer lead to scattered clusters of islands. Maximum adsorption corresponds to a bimodal island size distribution: very small islands and large ones that reflect the initiation of the colloidal aggregation. Source: Dissertation Abstracts International, Volume: 49-04, Section: B, page: 1288. Thesis (Ph.D.)--University of Windsor (Canada), 1988.

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