Doctoral Dissertations

Abstract

"Model interaction potentials for H2O on a basal f)-silver iodide substrate containing two types of defects, a potassium impurity and a four atomic layer ledge, are used to calculate optimal binding energy contours for the adsorbed H2O molecule. (J. Phys. Chern. 84, 1473(1980)). The model substrate with the potassium impurity appears to increase the optimal binding energy at the preferred adsorption sites to 23 kcal/rnol -- a value approximately 40 % larger than the maximal binding energy sites on the defect-free model silver-exposed basal plane of AgI. The impurity also distorts the hexagonal symmetry of the pref erred adsorption sites, drawing them towards the impurity. The four-layer ledge produces sites parallel to the ledge with optimal binding energy equal to 23 kcal/rnol compared to 20 (16) kcal/mol for maximal binding energy sites on the prism (iodine-exposed basal) face of the defect-free model AgI substrate. In a second study a formalism is presented for estimating the critical cluster size,n , and steady state nucleation rate, J, for adsorbed monolayer formation. The latter is combined with a Metropolis Monte Carlo technique and applied to water clusters on a featureless Lennard-Jones substrate with average H2O substrate binding energy and short-range forces parameters comparable to the model iodine-exposed basal AgI substrate. At 2 65 °K, the values 1< n* < 2 and, J ~ 1024cm-2 sec-l are predicted at water saturation. A comparison with results for water adsorbed on the model iodine-exposed basal AgI substrate (J. Chem. Phys. 78, 420(1983)) indicates that on both substrates a water mono layer forms rapidly and with approximately the same nucleation rate. The present results give an order of magnitude larger value of J for the smooth substrate and hence imply that the latter forms a monolayer at lower vapor pressures than the model AgI'--Abstract, p. ii

Advisor(s)

Hale, Barbara N., 1938-2024

Committee Member(s)

Alldredge, Gerald P.
Illegible Signature
Peacher, Jerry
Brown, Harry A., 1925-1995

Department(s)

Physics

Degree Name

Ph. D. in Physics

Publisher

University of Missouri--Rolla

Publication Date

Summer 1983

Pagination

xi, 77 pages

Note about bibliography

Includes bibliographical references (pages 60-63)

Rights

© 1983 Sergio Miguel Terrazas, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 4854

Print OCLC #

10994816

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