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Title:Gold Surfaces for Dropwise Condensation
Author(s):Woodruff, David Winfield
Department / Program:Chemical Engineering
Discipline:Chemical Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Engineering, Chemical
Abstract:Gold surfaces were investigated as promoters of dropwise condensation of steam at atmospheric pressure. Seven gold electroplating baths, one electroless immersion gold plating bath, and vacuum gold vapor deposition were used as deposition techniques. Five different surface preparation techniques of a pure gold sample were also tested. Gold deposits ranged in thickness from 100(ANGSTROM) to 20,000(ANGSTROM) with major emphasis from 200(ANGSTROM) to 5000(ANGSTROM). Auger electron spectroscopy and scanning electron microscopy were used to describe the heat transfer surfaces chemically and physically.
The deposits from the bright pure gold plating baths and the "acid, hard" baths produced deposits which resulted in dropwise condensation. Those deposits from the alloyed baths, the ultra-pure bath, and the vapor deposition gave mixed or filmwise condensation. Two surface preparations on the pure gold sample gave dropwise condensation, one gave mixed condensation, and two gave filmwise condensation. One deposit which was 2000(ANGSTROM) thick gave continuous dropwise condensation for over 1000 hours. The results indicate that gold is "self-promoting", adsorbing trace organics from the surroundings which serve to promote dropwise condensation. It appears that the role of the gold is to provide an oxide-free metallic surface.
Issue Date:1980
Type:Text
Language:English
Description:301 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
URI:http://hdl.handle.net/2142/66642
Other Identifier(s):(UMI)AAI8108707
Date Available in IDEALS:2014-12-13
Date Deposited:1980


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