title: Impact of solvent quality on the network strength and structure of alginate gels.
abstract: The influence of the mixture of water and alcohols on the solubility and properties of alginate and its calcium-induced gels is of interest for the food, wound care and pharmaceutical industries. The solvent quality of water with increasing amounts of ethanol (0-20%) on alginate was studied using intrinsic viscosity. The effect of ethanol addition on the rheological and mechanical properties of calcium alginate gels was determined. Small-angle X-ray scattering and transmission electron microscopy were used to study the network structure. It is shown that the addition of ethanol up to 15% (wt) increases the extension of the alginate chain, which correlates with increased moduli and stress being required to fracture the gels. The extension of the polymer chain is reduced at 20% (wt) ethanol, which is followed by reduced moduli and stress at breakage of the gels. The network structure of gels at high ethanol concentrations (24%) is characterized by thick and poorly connected network strands.
authors.affiliation: Applied Chemistry, Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Hermansson
authors.affiliation: Food and Bioscience, SP-Technical Research Institute of Sweden, Gothenburg, Sweden; SuMo Biomaterials, VINN Excellence Center, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Erich
authors.initials: E
authors.lastname: Schuster
authors.affiliation: SuMo Biomaterials, VINN Excellence Center, Chalmers University of Technology, Gothenburg, Sweden; Mölnlycke Health Care, P.O. Box 130 80, SE-40252, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Lindgren
authors.affiliation: Food and Bioscience, SP-Technical Research Institute of Sweden, Gothenburg, Sweden; SuMo Biomaterials, VINN Excellence Center, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Altskär
authors.affiliation: Applied Chemistry, Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden; SuMo Biomaterials, VINN Excellence Center, Chalmers University of Technology, Gothenburg, Sweden. Electronic address: anna.strom@chalmers.se.
authors.forename: Anna
authors.initials: A
authors.lastname: Ström
keywords: Ethanol; Hydrodynamic volume; Intrinsic viscosity; Rheology; Small-angle X-ray scattering; Water–ethanol mixture