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The interaction of sodium alginate with univalent cations
Author(s) -
Zhang Hucheng,
Zheng Honghe,
Zhang Qingzhi,
Wang Jianji,
Konno Mikio
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(199811)46:6<395::aid-bip4>3.0.co;2-1
Subject(s) - chemistry , sodium alginate , sodium , chemical engineering , polymer chemistry , organic chemistry , engineering
The M/G ratio, dyad and triad frequencies in the sodium alginate chain, were determined from 13 C‐nmr spectra. The interactions of sodium alginate in solution with the univalent cations K + ion and Na + ion have been investigated by viscometry and membrane osmometry. The dependencies of intrinsic viscosity, Huggins constant, and second virial coefficient on ionic strength were observed, and the maximums in reduced viscosity were obtained in low KCl and NaCl concentrations, respectively. These show that the electroviscous effects play an important role in polyelectrolyte solution, and the effect of the Na + ion on aqueous solution of sodium alginate is greater than the K + ion. The experimental observations are interpreted in terms of ion‐pair formation with carboxyl groups of mannuronate and isolated guluronate residues and cooperation “egg‐box” binding between polyguluronate chain sequence. The difference of interaction between univalent cations and alginate chains in solution is attributed to the ability of their binding with the polyion, which depends on the properties of ions itself. © 1998 John Wiley & Sons, Inc. Biopoly 46: 395–402, 1998