title: Modeling capillary formation in calcium and copper alginate gels.
abstract: Alginate solutions in the presence of bivalent ions can form ionic cross-linked gels. In particular gelation conditions the gel structure can be characterized by great anisotropy with the presence of straight capillaries along a preferential direction. These materials can find applications mainly in high-tech sectors, like tissue engineering, where the gel characteristics play a crucial role. Despite the need of mastering the capillary formation and properties, the process remains a poorly known problem, and its development is left to trial and error procedures. In this work a quantitative approach to the description of the capillary formation process has been developed. The theory proposed by Treml et al. (2003) has been implemented and extended to an alginate different from the one used in that study and two different ions (calcium and copper). Some of the model parameters have been derived through simple measurements; others have been scaled using proper scaling equations. Experiments have been performed in different gelation conditions, varying alginate and ionic solution concentrations, to highlight the effects of these parameters on the anisotropic structure and to validate the model. In all the analyses done, the model has performed nicely showing a good reliability in the prediction of gel characteristics like capillary formation, capillary length and process time.
authors.affiliation: Department of Industrial Engineering, University of Salerno, 84084 Fisciano, SA, Italy. Electronic address: dcaccavo@unisa.it.
authors.forename: Diego
authors.initials: D
authors.lastname: Caccavo
authors.affiliation: SuMo BIOMATERIALS, VINN Excellence Center, Chalmers University of Technology, Göteborg, Sweden; Pharmaceutical Technology, Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Ström
authors.affiliation: SuMo BIOMATERIALS, VINN Excellence Center, Chalmers University of Technology, Göteborg, Sweden; Pharmaceutical Technology, Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Anette
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Department of Industrial Engineering, University of Salerno, 84084 Fisciano, SA, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Lamberti
mesh_terms: D000464:Alginates / Q000737:chemistry*; D016880:Anisotropy; D002118:Calcium / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007477:Ions; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012996:Solutions; D013997:Time Factors
chemical_list: D000464:Alginates; D005782:Gels; D006603:Hexuronic Acids; D007477:Ions; D012996:Solutions; D003300:Copper; D020723:Glucuronic Acid; D002118:Calcium
keywords: Alginate; Gel capillaries; Ionotropic gelation; Modeling