Critical overlap concentration and intrinsic viscosity data of xanthan gum aqueous solutions in dimethyl sulfoxide

Abstract

This is the supplementary information of the research paper "Haemodynamics around confined microscopic cylinders" by Rodrigues et al. [1]. The critical overlap concentration of entanglement of polymer coils indicates whether a polymer solution is dilute or semidilute. Here, the reader will find the determination of $c^{*}$ for xanthan gum aqueous solutions in 52 wt.% of dimethyl sulfoxide, often used as non-particulate blood analogues. From the shear flow curves of a dilution series of the polymer the zero-shear viscosities ${\eta }_0$ were obtained, allowing us to estimate the intrinsic viscosity $\left[\eta \right]$ based on the xanthan gum concentration of the fluids. Two methodologies for doing so are described: using information from multi-concentration measurements and from a single polymer solution (rough estimate). With the intrinsic viscosity the determination of $c^{*}$ is straightforward.

Keywords: Critical overlap concentration; Dimethyl sulfoxide; Intrinsic viscosity; Polymer solutions; Xanthan gum.