title: Structure of Sodium Carboxymethyl Cellulose Aqueous Solutions: A SANS and Rheology Study.
abstract: We report a small angle neutron scattering (SANS) and rheology study of cellulose derivative polyelectrolyte sodium carboxymethyl cellulose with a degree of substitution of 1.2. Using SANS, we establish that this polymer is molecularly dissolved in water with a locally stiff conformation with a stretching parameter[Formula: see text]. We determine the cross sectional radius of the chain ([Formula: see text] 3.4 Å) and the scaling of the correlation length with concentration (ξ= 296c-1/2Å forcin g/L) is found to remain unchanged from the semidilute to concentrated crossover as identified by rheology. Viscosity measurements are found to be in qualitative agreement with scaling theory predictions for flexible polyelectrolytes exhibiting semidilute unentangled and entangled regimes, followed by what appears to be a crossover to neutral polymer concentration dependence of viscosity at high concentrations. Yet those higher concentrations, in the concentrated regime defined by rheology, still exhibit a peak in the scattering function that indicates a correlation length that continues to scale as[Formula: see text]. © 2014 The Authors. Journal of Polymer Science Part B: Polymer Physics Published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2015,53, 492-501.
authors.affiliation: Department of Chemical Engineering, Imperial College London London, SW7 2AZ, United Kingdom.
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Lopez
authors.affiliation: Diffraction and Materials Division, ISIS-STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX United Kingdom.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Rogers
authors.affiliation: Department of Materials Science and Engineering, The Pennsylvania State University, University Park Pennsylvania, 16802.
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Colby
authors.affiliation: Unilever Research Port Sunlight Laboratory Quarry Road East, Bebington L63 3JW, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Graham
authors.affiliation: Department of Chemical Engineering, Imperial College London London, SW7 2AZ, United Kingdom.
authors.forename: João T
authors.initials: JT
authors.lastname: Cabral
keywords: cellulose; neutron scattering; polyelectrolytes; rheology; structural characterization; water-soluble polymers