B.A. Korolev’s research while affiliated with Moscow State Forest University and other places

Structuring in aqueous and salt-containing aqueous solutions of poly(dimethyldiallyl ammonium chloride) in the concentration region close to the crossover concentration was studied by viscometry and quasi-elastic light scattering. In polyelectrolytes, crossover was shown to involve the development of oriented microdomain structure and is accompanied by no changes in the mass transfer mechanism upon viscous flow.

Rheological properties of concentrated polyelectrolyte solutions were studied using two samples of poly(N,N-dimethyldiallylammonium chloride) with different molecular masses. No anomalies in the viscosity behavior were observed in a broad range of concentrations, temperatures, and ionic strengths of solutions. The activation energies Ea of viscous flow were calculated for various solution concentrations and a concentration region featuring a change in the mechanism of mass transfer and the formation of a fluctuation network of entanglements was determined with the aid of a scaling approach. It was found that this region, independent of the molecular mass of polyelectrolyte, is situated significantly above the crossover concentration determined using the inverse intrinsic viscosities and is essentially the region of concentrations corresponding to the screening of electrostatic interactions, between macromolecular segments. In the presence of a low-molecular-mass electrolyte, the screening concentration somewhat decreases and the strength of the fluctuation entanglement network.