title: In situ chitosan gelation initiated by atmospheric plasma treatment.
abstract: This work reports on the feasibility of atmospheric dielectric barrier discharge (DBD) plasma as a novel synthetic pathway for the liquid phase gelation of chitosan. The DBD plasma chitosan gelation process did not significantly alter the chemical structure of the biopolymer as confirmed by FTIR study. However, the oxidation processes and local heating effect associated with the solvent evaporation during the plasma treatment could provoke both reaction of chitosan degradation and the cleavage of β-1-4-glycosidic linkages with the concomitant generation of aldehyde groups able to crosslink via Schiff-base with amino groups from other chitosan molecules. Shear viscosity measurements suggested the formation of chitosan fragments of lower molecular weight after the plasma treatment of 1% (w/v) chitosan and fragments of higher molecular weight after the plasma treatment of 2% (w/v) chitosan. The crosslinking density of hydrogels generated during the in situ DBD plasma chitosan gelation process increased as a function of the treatment time and concentration of chitosan. As of consequence of the increase of the cross-linking density, the equilibrium swelling ratio and water content decreased significantly.
authors: Chemical and Biomolecular Nanotechnology Department, Institute of Advanced Chemistry of Catalonia (IQAC), Consejo Superior de Investigaciones Científicas (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain. Electronic address: ricardo.molina@iqac.csic.es.
authors: R
authors: R
authors: Molina
authors: Textile Engineering Department, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia. Electronic address: pera@tmf.bg.ac.rs.
authors: P
authors: P
authors: Jovancic
authors: Chemical and Biomolecular Nanotechnology Department, Institute of Advanced Chemistry of Catalonia (IQAC), Consejo Superior de Investigaciones Científicas (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain. Electronic address: svmqst@cid.csic.es.
authors: S
authors: S
authors: Vilchez
authors: Group of Molecular and Industrial Biotechnology, Department of Chemical Engineering, Universitat Politècnica de Catalunya, Rambla St. Nebridi 22, 08222 Terrassa, Spain. Electronic address: tzanko.tzanov@upc.edu.
authors: T
authors: T
authors: Tzanov
authors: Chemical and Biomolecular Nanotechnology Department, Institute of Advanced Chemistry of Catalonia (IQAC), Consejo Superior de Investigaciones Científicas (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain. Electronic address: conxita.solans@iqac.csic.es.
authors: C
authors: C
authors: Solans
keywords: Chitosan; DBD plasma; Hydrogels; In situ gelation; Swelling