J. Phys. II France
Volume 3, Number 1, January 1993
Page(s) 1 - 7
DOI: 10.1051/jp2:1993105
J. Phys. II France 3 (1993) 1-7

Sol-gel transition of alginate solution by addition of calcium ions: alginate concentration dependence of gel point

Zheng-Yu Wang, Quinz-Zhi Zhang, Mikio Konno and Shozaburo Saito

Departement of Molecular Chemistry and Enginnering, Faculty of Engineering, Tohoku University, Aramaki Aoba, Aoba-ku Sendai 980, Japan

(Received 15 September 1992, revised 17 November 1992, accepted 25 November 1992)

Polyelectrolyte concentration dependence of gel point was experimentally investigated for alginate solution by addition of calcium ions. A power law relation was found between the gelation threshold $f_{\rm c}$ and alginate concentration C with an exponent of $-0.65\pm 0.05$. It was shown that the experimental results can be explained in terms of the scaling theories developed for vulcanization process and polyelectrolytes in semi-concentrated solutions. Based on the scaling analysis, a good agreement was obtained between the experimental and theoretical exponents.


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