6533b851fe1ef96bd12a8e34
RESEARCH PRODUCT
Intrinsic viscosities of polyelectrolytes in the absence and in the presence of extra salt: Consequences of the stepwise conversion of dextran into a polycation.
Andreas EichBernhard A. WolfLuminita GhimiciMarieta Nichiforsubject
chemistry.chemical_classificationPolymers and PlasticsChemistryIntrinsic viscosityRelative viscosityOrganic ChemistryViscometerThermodynamicsPolymerFlory–Huggins solution theoryPolyelectrolytesymbols.namesakeBoltzmann constantPolymer chemistryMaterials ChemistrysymbolsOrder of magnitudedescription
Abstract Viscosities of dilute polymer solutions were measured in capillary viscometers for samples varying in their fraction f of charged units from 0.00 to 0.90. The dependence of the logarithm of the relative viscosity on polymer concentration c is in all cases reproduced quantitatively by three characteristic parameters: [ η ], the intrinsic viscosity; B , a viscometric interaction parameter (related to the Huggins constant); [ η ] , a parameter required only for polyelectrolytes at low concentrations of extra salt. In pure water [ η ] increases more than 80 times as the fraction f rises from zero to 0.90 and [ η ] starts from zero and goes up to ≈71 mL/g. Upon the addition of NaCl [ η ] decreases by at least one order of magnitude (depending on the value of f ). The observed dependences of log [ η ] on log c salt can be modeled quantitatively by Boltzmann sigmoids.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-06-16 | Carbohydrate polymers |