| Abstract
| - The dielectric properties of a typical ionic food polysaccharide,alginates with different chemicalcompositions and molecular sizes, were investigated with specialrelevance to the solution viscosity.The dielectric relaxation around 1 MHz due to the fluctuation ofbound counterions was analyzed.The polymer concentration, C, dependence of thedielectric increment, Δε, and that of the relaxationtime, τ, are summarized as Δε ∝ C1/3and τ ∝ C-2/3 at the diluteregion and as Δε ∝ C0 and τ ∝C-1at the semidilute region for all of the samples, in good agreement withthe scaling relations predictedby polyelectrolyte solution theories. The crossover concentration,C*, from the dilute to the semidiluteregion was determined as the concentration at the intersection of thetwo regions. The concentrationdependence of the relative viscosity, ηrel, was alsoexpressed by two scaling equations: (ηrel − 1)∝C1 at low concentration andηrel ∝ C1/2 at highconcentration. The crossover concentration,C*,determined by the viscosity agreed with that determined by thedielectric measurement. Theseresults suggest that the behavior of the physical properties of thefood polysaccharide solutionswould be understandable on the basis of the scaling concept, thedielectric relaxation measurementbeing an effective method for analyzing the polyelectrolyte solutionstructure contributing to thephysical properties of the systems. Keywords: Dielectric relaxation; viscosity; alginate; scalinglaw
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