abstract:

We investigated the structure and the dynamic properties of low molecular weight hydrophobic polyelectrolytes in aqueous solution, through viscosity and conductivity measurements and with different static and dynamic scattering techniques.

We demonstrated that this type of polymers may aggregate in water depending on two main parameters: the charge fraction on the polymer chain and the amount of hydrophobic groups. The presence of salt, the nature of the counterion or the polymer concentration change the characteristics of the aggregates. The short range structure is therefore a competition between attraction between hydrophobic groups and electrostatic repulsion between charged groups.

The dynamics of these short polyelectrolyte chains in dilute solution is dominated by the counterion distribution around the polymer chains. Depending on the charge distribution on the polymer chain, an important part of the counterions may be located close to the chain. These counterions increase the viscosity by an electroviscous effect. Slow polymer chains fluctuations are also taking place in solution and are influenced by the counterion distribution.

More details : mail to Christophe Dumousseaux

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