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C6‐oxidized cellulose: Ion interactions with mono‐ and divalent cations
Author(s) -
Cantoni Carolina,
Zennaro Francesca,
Bertocchi Claudia,
Mariotti Paolo,
Rizzo Roberto
Publication year - 1998
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/(sici)1097-0282(199802)45:2<157::aid-bip6>3.0.co;2-r
Subject(s) - chemistry , counterion , divalent , cellulose , aqueous solution , ionic strength , ionic bonding , polymer , ion , crystallography , organic chemistry
The conformational behavior of different molecular weight fractions of a synthetic C6‐oxidized derivative of cellulose were investigated by means of capillary viscometry, CD, and microcalorimetric measurements. Experiments were carried out in the presence of either monovalent or divalent counterions. The experimental data indicated that C6‐oxidized cellulose can assume an ordered extended conformation at low ionic strength, induced by the intrachain repulsions of negative charges. This conformation was suggested to be very similar to the fully extended structure of cellulose. In addition to this, upon increasing the ionic strength, a conformational transition of the order‐to‐disorder type occurred. In fact, the screening of the electrostatic repulsions introduced a number of conformational kinks into the cellulosic backbone, which enabled the polymer to assume a more coiled conformation hence producing less viscous aqueous solutions. © 1998 John Wiley & Sons, Inc. Biopoly 45: 157–163, 1998