ISSN:
0887-6266
Schlagwort(e):
polyacrylamides
;
specific viscosity
;
polyelectrolyte solutions
;
light scattering
;
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
The dependences of the specific viscosity of several polyelectrolytes on polyelectrolyte concentration, salt concentration or solution ionic strength, solution pH value, solvent quality, and solution temperature were systematically investigated. We found that the specific viscosity obeys a more general relation: ηsp = Acp2/(cp + 2cs)3/2 + B, where ηsp is the polyelectrolyte specific viscosity, cp and cs are polymer and salt concentrations, respectively. The prefactor A depends critically on chain size, solvent quality, and temperature in qualitative agreement with the theory proposed by Rabin et al. The intercept B is nonzero or less than zero in polyelectrolyte solutions with low ionic strength. When a sufficient amount of salt has been added, B is reduced to zero and we recover the Rabin et al.'s relation. The physical interpretation for the intercept B is that it represents the inverse of the strength of electrostatic interaction between a polyion and counterions, in quantitative agreement with the well-known emperical Fuoss's relation. Furthermore, the existence of nonzero B allows us to calculate the condition for the maximum in the reduced viscosity-polymer concentration curve in a polyelectrolyte solution system without salt. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 743-753, 1998
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
