Open AccessStructure of sodium carboxymethyl cellulose aqueous solutions: A SANS and rheology study
Author(s) -
Lopez Carlos G.,
Rogers Sarah E.,
Colby Ralph H.,
Graham Peter,
Cabral João T.
Publication year - 2014
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/polb.23657
Subject(s) - rheology , carboxymethyl cellulose , radius of gyration , polymer , polyelectrolyte , neutron scattering , hydrodynamic radius , intrinsic viscosity , aqueous solution , viscosity , thermodynamics , polymer chemistry , chemistry , scaling , small angle neutron scattering , materials science , scattering , sodium , organic chemistry , physics , optics , geometry , mathematics , copolymer
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 B ≃ 1.06 . We determine the cross sectional radius of the chain ( r p ≃ 3.4 Å) and the scaling of the correlation length with concentration ( ξ = 296 c −1∕2 Å for c in 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 asc − 1 / 2. © 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