Thixotropy of Highly Viscous Sodium (Carboxymethyl)cellulose Hydrogels

Abstract

A general method to quantify the thixotropic behavior of systems with very low thixotropy is proposed. The areas enclosed by the rheograms tau = f(gamma) must be fitted to functions with well-determined boundary conditions. From these equations the corresponding thixotropic areas are obtained, together with the theoretical area enclosed by the rheogram corresponding to the maximum rheodestruction. The proposed method is applied to high viscosity sodium (carboxymethyl)cellulose gels.

Viscosity and Scaling of Semiflexible Polyelectrolyte NaCMC in Aqueous Salt Solutions

“…in aqueous, salt-free solutions has been studied previously. 6,[17][18][19][20][21][22][23][24][25][26] A power law dependence of the specific viscosity (η sp = (η − η s )/η s where η is the solution viscosity and η s is the solvent viscosity) in the semidilute nonentangled regime close to the Fuoss law 27 (η sp ∼ c 1/2 ) is usually observed, where c is the polymer concentration. …”

Rheological properties of high concentrations of carboxymethyl cellulose solutions

“…[1][2][3][4][5][6][7] Sikkema and Janssen 4 attempted to prepare CMCs with properties similar to xanthan gum solutions. They manipulated the alkalinity during CMC preparation and produced a complex CMC colloid fiber.…”

“…three separate tests were performed to detect any possible deformation behavior for the concentrations of CMC of 5-8%. Yield stress was analyzed on the resulting plots of versus ␥, which are defined by conclusions from the literature [7][8][9]. Figure 7shows the yield stress response for all the concentrations used.…”

A Time‐Dependent Expression for Thixotropic Areas. Application to Aerosil 200 Hydrogels

“…From the areas enclosed by the rheograms corresponding to the different agitation times, the following time-dependent expression may be obtained 2 :…”