Doctoral Dissertations

Title

Interactions between water and phosphate glasses

Keywords and Phrases

Aqueous dissolution; Aluminophosphate

Abstract

"The reactions between phosphate glasses and water have been characterized in a number of different environments. The weathering and aqueous dissolution properties of these glasses are presented under a range of temperature, humidity, and pH conditions. During the dissolution process, water is first absorbed by the glass surface and hydrated the surface disassociated the phosphate network and modifying cations. Once disassociated, the cations and chains are removed congruently from the glass surface. During these experiments it has been found that the addition of high field strength modifiers or the change in glass structure from the meta toward the pyrophosphate composition may be unable to improve the durability of the glass systems on their own. The weathering reactions of phosphate occur in a similar manner, with water initially absorbed by the glass surface and hydrating the modifiers and the phosphate network, isolating them from each other. It then continues with hydrolysis of the phosphate chains on the glass surface, and the production of a visible reaction layer, and can eventually lead to the precipitation of crystalline orthophosphate species on the glass surface. Modifying cations such as Al³⁺ that can form bonds with lower ionic character can help to prevent water from hydrating the glass network. The phosphate network itself can also become more resistant to hydration as shorter phosphate chains appear to form stronger P-O-M bonds and also may electrostatically repel water. These high field strength modifiers will, however, accelerate the hydrolysis process once the surface is hydrated"--Abstract, leaf iv.

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Publisher

University of Missouri--Rolla

Publication Date

Fall 2005

Journal article titles appearing in thesis/dissertation

  • Glass corrosion background
  • Aqueous reactions of aluminophosphate glasses
  • Weathering reactions of phosphate glasses
  • NMR study of reactions between aluminophosphate glasses and water

Pagination

xiv, 173 leaves

Note about bibliography

Includes bibliographical references.

Rights

© 2005 Brad Conrad Tischendorf, All rights reserved.

Document Type

Dissertation - Citation

File Type

text

Language

English

Library of Congress Subject Headings

Glass -- Corrosion
Corrosion and anti-corrosives

Thesis Number

T 8847

Print OCLC #

76913515

Link to Catalog Record

Full-text not available: Request this publication directly from Missouri S&T Library or contact your local library.

http://laurel.lso.missouri.edu/record=b5729687~S5

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