Interfacial shear rheology of interacting carbohydrate polyelectrolytes at the water–oil interface using an adapted conventional rheometer

• Published in: Carbohydrate polymers Vol. 57; no. 1; pp. 45 - 54
• Main Authors: Pérez-Orozco, J.P, Beristain, C.I, Espinosa-Paredes, G, Lobato-Calleros, C, Vernon-Carter, E.J
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 12.08.2004; Elsevier Science
• Subjects: Applied sciences; Carbohydrate polyelectrolytes; Electrostatic interactions; Exact sciences and technology; Interfacial creep compliance-time properties; Interfacial shear viscosity; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; Electrostatic interactions; Carbohydrate polyelectrolytes; Interfacial creep compliance-time properties; Interfacial shear viscosity; Prosopis; Long term variation; Experimental study; Polyelectrolyte; Interface properties; Shear viscosity; Adsorbed layers; Leguminosae; Creep curve; Natural gum; Dicotyledones; Angiospermae; Liquid liquid interface; Oside polymer; Spermatophyta; Interpolymer; Chitosan; Oil water contact; Apparent viscosity
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2004.03.022

A conventional rheometer was adapted for carrying out interfacial shear measurements. The interfacial shear viscosity and the interfacial creep compliance-time properties of mesquite gum or mesquite gum–chitosan mixed films were determined at the water–mineral oil interface. The ratio of chitosan to mesquite gum, and aging time, influenced the interfacial shear viscosity and interfacial creep compliance-time properties of the films. Electrostatic coulombic interactions arose between the negatively charged mesquite gum and the positively charged chitosan molecules, and the strength of the interaction was influenced by the relative charge density between both biopolymers. The interfacial shear viscosity and the interfacial viscoelastic properties of films obtained from 10% (w/w) mesquite gum aqueous solutions were boosted by the addition of chitosan at concentrations of 0.2–0.6% (w/w), but depressed by addition of chitosan at concentrations of 0.8–1.0% (w/w).