On the percolation of alginate/calcium systems at low concentrations. (10th February 2016)

• Record Type: Journal Article
• Authors: Khavari, Adele; Löfroth, Jan-Erik; Bergenholtz, Johan; Nydén, Magnus
• Is Part Of: Carbohydrate polymers. Volume 137(2016)
• Page Start: 480
• Page End: 487
• Publication Date: 2016-02-10
• Subjects: Structure dynamics -- Alginate -- Dynamic light scattering -- Gel; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2015.11.019
• Languages: English
• ISSNs: 0144-8617

Abstract

Abstract: The sol-to-gel transition of an alginate rich in β-d -mannuronic acid residues and at a concentration of 0.1% w/v in 15 mM NaCl in the presence of calcium ions of 0 to 3.5 mM was studied with dynamic light scattering. The dynamics of the different systems added further insight into the alginate gel forming mechanisms. Below a Ca 2+ concentration of 0.7 mM, the build-up of small aggregates could be verified. Moreover, at a critical concentration, close to 0.9 mM Ca 2+, a percolated, non-ergodic network started to form from some of these aggregates, with smaller aggregates still diffusing in the network. The system displayed strong non-ergodicy at high Ca 2+ concentrations with a non-ergodicity parameter that appeared to form discontinuously from near zero to a clearly non-zero value at the critical Ca 2+ concentration.