Surface structure of kaolinite from the detailed analysis of gas/solid adsorption isotherms

Authors
Papanu, Steven C.
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Other Contributors
Ross, Sydney, 1915-
Hollinger, Henry B.
Janz, George J.
Habetler, George J.
Issue Date
1976-06
Keywords
Colloid and interfacial chemistry
Degree
PhD
Terms of Use
This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
Full Citation
Abstract
A single dioctahedral sheet of gibbsite is unstable when isolated. It requires the presence of adjacent layers of either water or other gibbsite layers to exist. Approximately half of the kaolinite surface is undistinguishable from the pyrophyllite surface. This surface was well characterized on the kaolinite sample used in this work, and it is believed to be the oxygen surface formed by the tetrahedral silica sheet. The other half of the surface, believed to be the gibbsite-like, dioctahedral sheet, has a greater adsorptive potential for nitrogen than the silica sheet, but was not well characterized on the present sample. The gibbsite-like surface of this kaolinite was partially dehydrated under a vacuum at 125°C and partially dissolved at pH 3.5 in the size-fractionation process. This alteration of the gibbsite-like surface was unintentional, and was revealed only by the CAEDMON substrate analysis technique. In addition, a new, lower, structural dehydration, decomposition temperature for kaolinite was reported: it is 200°C. Finally, the failure of the B.E.T. equation to adequately describe adsorption data on homotattic substrates was explained in terms of registry of the adsorbate by the substrate.
Description
June 1976
School of Science
Department
Dept. of Chemistry and Chemical Biology
Publisher
Rensselaer Polytechnic Institute, Troy, NY
Relationships
Rensselaer Theses and Dissertations Online Collection
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