Comparison between Experimental Results Obtained with Hydroxylated Polyacids and some Theoretical Models

Centre de Recherches sur les Macromolecules Vegetales (C.N.R.S.) - 38 - Grenoble, France 

We intend to present first a set of experimental data concerning the equilibrium properties (pK, activity of counterions) of polyelectrolytes in salt free solutions in a second part, these results are compared with theoretical values obtained when a rod-like model is adopted in the Lifson-Katchalsky, Manning and Oosawa treatments. The polyelectrolytes tested are respectively polysaccharides (alginic and pectic acids), carboxymethylated derivatives of cellulose (CMC), dextran (CMD), amylose (CMA), and sulphonic derivatives of polyvinyl alcohol. The essential difference between them is local rigidity. It is possible to vary by synthesis the degree of substitution and consequently the linear charge density our data are given for dilute aqueous solutions (2 X 10 N-5 X 10 N) at 25°C. 

The fundamental parameter is the linear charge density 2 proposed by Lifson and Katchalsky [1] is given by the relation  

In the particular case of polysaccharide derivatives characterized by their SS (the mean number of carboxyl groups per monomeric unit of length b) and degree of neutralization a, relation (1) can be written  

Eric Selegny fed.). Polyelectrolytes, 157-193. All Rights Reserved. Copyright 1974 by D. Reidel Publishing Company, Dordrecht-Holland. 

---

M. Rinaudo, Comparison between experimental results obtained with hydroxylated polyacids and some theoretical models, in Polyelectrolytes, E. Sdldgny, M. Mandel, and U. P. Strauss, eds., D. Riedel, Dordrecht, the Netherlands, 1974, p. 157. 

COMPARISON BETWEEN EXPERIMENTAL RESULTS OBTAINED WITH HYDROXYLATED POLYACIDS AND SOME THEORETICAL MODELS... 

---