ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
In order to clarify the effect of degree of substitution of ionic and hydrophobic group on the polyelectrolytic behavior of polysaccharides, potentiometric titration and activity measurement of counterions were made for carboxymethyldextran (Cm-dextran) having various degrees of substituted carboxyl group and for carboxymethylbenzyldextran (Cm-Bzl-dextran) containing various degrees of substituted benzyl group. From the shape of titration curve, no conformational change was observed for both Cm-dextran and Cm-Bzl-dextran. The pK0 value of Cm-dextran was independent of the degree of the degree of substituted carboxy group. However, the pK0 of Cm-Bzl-dextran increased with an increasing degree of substituted benzyl group. The suppression of dissociation of a carboxyl group, caused by the surrounding hydrophobic groups, was discussed mainly in terms of the change of water structure around such groups. From the results of activity measurement for counterions of these dextran derivatives, we proposed the possibility of ion selectivity based on the hydrophobicity.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1975.360141211
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