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Oxidation of cellulose microfibril segments by alkaline silver nitrate and its relation to the fine structure of cellulose
Author(s) -
Colvin J. Ross
Publication year - 1964
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1964.070080622
Subject(s) - microfibril , cellulose , chemistry , dissolution , polymer chemistry , crystallography , silver nitrate , lyocell , chemical engineering , organic chemistry , fiber , engineering
The oxidation by alkaline silver nitrate of segments (ca 0.1 μ long) of cellulose microfibrils from Avena coleoptiles, ramie, bacteria, and Valonia has been followed by electron microscopy. For comparison, chitin microfibrils have been oxidized by the same reagent and observed by the same method. Oxidation proceeds equally at both ends of the segments, as judged by the rate of deposition of colloidal silver. As a consequence of oxidation, dissolution of the ordered array of 1→4β‐polyglucosan chains (or poly‐ N ‐acetylglucosamine chains) takes place rapidly from both ends, due to Coulomb repulsion between ionized carboxyl groups and/or electrostriction of water molecules about the same groups. The observations are consistent with the assumption that the neighboring chains run in opposite directions in the cellulose microfibril (i.e., with the Meyer‐Misch antiparallel postulate). They are not in agreement with expectations based upon the parallel arrangement.