Rheological and drag reduction characteristics of xanthan gum solutions

Abstract

Abstract:The rheological and turbulent drag reducing characteristics of commercial and purified xanthan gum solutions of concentrations 50-500 ppm have been studied with and without addition of 100 ppm NaC1. The purification by soxlet extraction of xanthan gum using 95 % ethanol is effective in removing low-molecular-weight impurities from xanthan. The increased content of higher molecular-weight xanthan in purified xanthan is evident from theological and drag reduction behavior. The addition of 100ppm salt to dilute solutions introduces semi-flexibility in xanthan gum solution without occurrence of self-association. The change in molecular behavior in the presence of salt is evident from rheological normal-stress and turbulent drag reduction behaviors.

Friction Factors For Pipe Flow Of Xanthan- Based Concentrates Of Fire Fighting Foams

“…4. At lower concentrations, in the order of 500 to 2000 ppm, xanthan gum acts as a drag suppressor [14]; i.e., less concentrated solutions of xanthan gum, than those studied in this paper, display very different behaviour in the turbulent regime. Critical Re MR = 1190…”

“…Clearly, foam concentrates containing xanthan gum which is know for its significant elasticity [6,8,14] …”

Polymer degradation of dilute solutions in turbulent drag reducing flows in a cylindrical double gap rheometer device

“…Schematic illustration of the axial symmetric double gap and the TaylorCouette geometry utilised in the present work. [21,22,16,2], we are measuring G 0 here in an attempt to associate the drag reduction effectiveness with some common viscoelastic property.…”

Water Soluble Polymers

“…Due to its ability for rheological control in aqueous systems, XG has been widely used in industries. In the case of agricultural applications, XG has been used to enhance the fluidity of fungicides and insecticides [88]. Moreover, XG can produce a high shear viscosity polymer solution at low concentrations or under shear forces, which makes it effective as a thickener and stabilizer in the food and petroleum industries, such as in cosmetics, toothpastes, oil drilling fluids, enhanced oil recovery, and pipeline cleaning [89].…”