Spectrum of hydrodynamic volumes and sizes of macromolecules of linear polyelectrolytes versus their charge density in salt-free aqueous solutions. Issue 15 (5th April 2018)

• Record Type: Journal Article
• Authors: Pavlov, Georges M.; Dommes, Olga A.; Okatova, Olga V.; Gavrilova, Irina I.; Panarin, Evgenii F.
• Is Part Of: Physical chemistry chemical physics. Volume 20:Issue 15(2018)
• Page Start: 9975
• Page End: 9983
• Publication Date: 2018-04-05
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c8cp01329b
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Viscous flow was studied in salt-free solutions of random N -methyl- N -vinylacetamide copolymers that varied in the average number of charged units. The ranges are determined where the effect of the average charge density manifests itself in different ways. Abstract : Molecular characteristics of statistical copolymers based on hydrophilic poly( N -methyl- N -vinylacetamide) have been monitored throughout the entire possible range of charge density from 1.5 to 39 mol%. Different trends in the dependence of intrinsic viscosity on the average charge density of polymer chains at minimal ionic strength were revealed. A new parameter, l qq / A bare, describing this behavior was proposed ( l qq is the average distance between the neighboring charges along the chain, and A bare is the statistical segment length of a non-charged homologue). For polyelectrolyte chains, this parameter allows the regions of charge density values where electrostatic long-range or short-range interactions dominate to be indicated. Two homologous series of copolymers were characterized by methods of molecular hydrodynamics under conditions of suppressed charge effects. Intrinsic viscosity in salt-free solutions characterizing an individual macromolecule was estimated by a method proposed earlier [Pavlov et al., Russ. J. Appl. Chem., 2006, 79, 1407–1412].