Anomalous viscosity behavior in aqueous solutions of hyaluronic acid

• Published in: Polymer bulletin (Berlin, Germany) Vol. 59; no. 2; pp. 217 - 226
• Main Authors: MALEKI, Atoosa, KJØNIKSEN, Anna-Lena, NYSTRÖM, Bo
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.09.2007; Berlin Springer Nature B.V; New York, NY
• Subjects: Alignment; Applied sciences; Aqueous solutions; Chains (polymeric); Dilution; Exact sciences and technology; Fractionation; Hyaluronic acid; Hydrogen bonding; Natural polymers; Physicochemistry of polymers; Polymers; Shear flow; Shear rate; Shear thinning (liquids); Shear viscosity; Starch and polysaccharides; Viscosity; Windows (intervals); Semidilute solution; Shear flow; Temperature effect; Experimental study; Shear thinning; Intermolecular interaction; Polyelectrolyte; Shear viscosity; Dilute solution; Glycosaminoglycan; Oside polymer; Aqueous solution; Hyaluronic acid; Hydrogen bond; Rheological properties
• ISSN: 0170-0839; 1436-2449
• DOI: 10.1007/s00289-007-0760-2

SummaryEffects of steady shear flows on intermolecular interactions in dilute and semidilute aqueous solutions of hyaluronic acid (HA) are reported. Pronounced shear thinning behavior is observed for solutions of HA at high shear rates, and no hysteresis effects are detected upon the subsequent return to low shear rates. With the aid of the asymmetric flow field-flow fractionation (AFFFF) technique, it is shown that mechanical degradation of the polymer does not take place in these shear viscosity experiments, even at high shear rates. The low shear rate viscosity of a semidilute HA solution decreases by approximately 40% when the temperature is increased from 10 °C to 45 °C. It is shown that when a dilute HA solution is exposed to a low fixed shear rate (0.001 s-1), a marked viscosification occurs in the course of time and prominent intermolecular complexes are formed. It is argued that shear-induced alignment and stretching of polymer chains promote the evolution of hydrogen-bonded structures, where cooperative zipping of stretched chains generates a network. At a higher constant shear rate (0.1 s-1), the viscosity decreases as time goes because of the alignment of the polymer chains, but the higher shear flow perturbation prevents the chains in dilute solutions from building up association complexes. The viscosity of an entangled HA solution is not changed in the considered time window at this shear rate, but the network structures breakdown at the highest shear rate (1000 s-1), and then they are restored upon return to a low shear rate.