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The osmotic coefficients of the sodium form of some biopolymers
Author(s) -
Jang Larry K.,
Quintero Ernesto J.,
Gordon Grisel,
Röhricht Markus,
Geesey Gill G.
Publication year - 1989
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/bip.360280812
Subject(s) - chemistry , dilution , sodium , counterion , alginic acid , counterion condensation , activity coefficient , salt (chemistry) , polymer , ionization , sodium salt , chromatography , thermodynamics , analytical chemistry (journal) , inorganic chemistry , aqueous solution , ion , organic chemistry , biochemistry , physics
The osmotic coefficients ϕ p,Na of dilute solutions of the sodium form of some weakly acidic polymers are theoretically predicted in this work. Based on the measured value 0.73 of γ Na , the activity coefficient of free Na + , of the completely ionized humic acid (sodium salt) in a salt‐free solution, the effective interligand distance b is calculated to be 11.34 Å by using Manning's counterion condensation theory [Manning, G. S. (1969) J. Chem. Phys. 51 (3), 924]. The corresponding values of γ Na (measured experimentally) and b for the completely ionized exopolymer of Pseudomonas atlantica are 0.624 and 7.57 Å when cultivated at a dilution rate D = 0.015 h −1 , 0.647 and 8.19 Å at D = 0.025 h −1 , and 0.613 and 7.29 Åat D = 0.06 h −1 . For alginic acid (in the completely ionized sodium form), γ Na = 0.40 and b = 4.71 Å. The osmotic coefficients ϕ p,Na for the partially and the completely ionized polymers are then predicted with Manning's theory as well.