Thixotropy of highly viscous sodium (carboxymethyl)cellulose hydrogels.

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.