title: Fine microstructure of processed chitosan nanofibril networks preserving directional packing and high molecular weight.
abstract: Crystalline chitosan nanofibril networks were prepared, preserving the native structural packing and the polymer high molecular weight. The fine microstructure of the nanomaterial, obtained by mild hydrolysis of chitosan (CHI), was characterized by using synchrotron small- and wide-angle X-ray scattering (SAXS and WAXS), transmission electron microscopy (TEM) and electron diffraction. Hydrolysis of chitosan yielded a network of crystalline nanofibrils, containing both allomorphs of chitosan: hydrated and anhydrous. The comparison of WAXS data in transmission and reflection mode revealed the preferential orientation of the CHI crystals when subjected to mechanical compression constrains. The results are in agreement with the existence of a network nanostructure containing fiber-like crystals with the principal axis parallel to the polymer chain axis. The evolution of the CHI allomorphic composition with temperature was studied to further elucidate the mechanism of structural transitions occurring during CHI nanofibril network processing.
authors.affiliation: Institute of Microsystems Engineering IMTEK-Sensors, Albert Ludwig University of Freiburg, D-79110 Freiburg, Germany; Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Science Park Golm, D-14424 Potsdam, Germany. Electronic address: anayancy.osorio@imtek.uni-freiburg.de.
authors.forename: Anayancy
authors.initials: A
authors.lastname: Osorio-Madrazo
authors.affiliation: Ingénierie des Matériaux Polymères (IMP, UMR 5223 - CNRS), Université de Lyon, Université Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: David
authors.affiliation: Center of Biomaterials, University of Havana, 10600 Ciudad de La Habana, Cuba.
authors.forename: Carlos
authors.initials: C
authors.lastname: Peniche-Covas
authors.affiliation: Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales CERMAV, F-38000 Grenoble, France; CNRS, CERMAV, F-38000 Grenoble, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Rochas
authors.affiliation: Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales CERMAV, F-38000 Grenoble, France; CNRS, CERMAV, F-38000 Grenoble, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Putaux
authors.affiliation: Ingénierie des Matériaux Polymères (IMP, UMR 5223 - CNRS), Université de Lyon, Université Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Trombotto
authors.affiliation: Ingénierie des Matériaux Polymères (IMP, UMR 5223 - CNRS), Université de Lyon, Université Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Alcouffe
authors.affiliation: Ingénierie des Matériaux Polymères (IMP, UMR 5223 - CNRS), Université de Lyon, Université Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Domard
mesh_terms: D000107:Acetylation; D048271:Chitosan / Q000737:chemistry*; D003460:Crystallization; D006868:Hydrolysis; D008970:Molecular Weight; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
chemical_list: D048271:Chitosan
keywords: Acid hydrolysis; Chitosan allomorphs; Chitosan nanofibril networks; Fiber-like nanocrystals; Synchrotron X-ray scattering