title: An Interesting Class of Porous Polymer--Revisiting the Structure of Mesoporous α-D-Polysaccharide Gels.
abstract: The processes involved in the transformation of non-porous, native polysaccharides to their highly porous equivalents introduce significant molecular complexity and are not yet fully understood. In this paper, we propose that distinct changes in polysaccharide local short-range ordering promotes and directs the formation of meso- and micro-pores, which are investigated here using N2 sorption, FTIR, and solid-state (13)C NMR. It is found that an increase in the overall double helical amylose content, and their local association structures, are responsible for formation of the porous polysaccharide gel phase. An exciting consequence of this local ordering change is elegantly revealed using a (19)F NMR experiment, which identifies the stereochemistry-dependent diffusion of a fluorinated chiral probe molecule (1-phenyl-2,2,2-trifluoroethanol) from the meso- to the micro-pore region. This finding opens opportunities in the area of polysaccharide-based chiral stationary phases and asymmetric catalyst preparation.
authors.affiliation: Green Chemistry Centre of Excellence, University of York, Department of Chemistry, Heslington, York, YO10 5DD, UK. robin.white@ise.fraunhofer.de.|FMF-Freiburger Materialforschungszentrum, Stefan-Meier-Straße 21, 79104, Freiburg, Germany. robin.white@ise.fraunhofer.de.|Sustainable Catalytic Materials Group, Hydrogen Technologies Division, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110, Freiburg, Germany. robin.white@ise.fraunhofer.de.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: White
authors.affiliation: Departamento de Física de Polímeros, Elastómeros y Aplicaciones Energéticas, Instituto de Ciencia y Tecnología de Polímeros, CSIC, c/Juan de la Cierva 3, 28006, Madrid, Spain.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Shuttleworth
authors.affiliation: Green Chemistry Centre of Excellence, University of York, Department of Chemistry, Heslington, York, YO10 5DD, UK.
authors.forename: Vitaliy L
authors.initials: VL
authors.lastname: Budarin
authors.affiliation: Green Chemistry Centre of Excellence, University of York, Department of Chemistry, Heslington, York, YO10 5DD, UK.
authors.forename: Mario
authors.initials: M
authors.lastname: De Bruyn
authors.affiliation: Universität Freiburg, Institut für Anorganische und Analytische Chemie, Albertstraße 21, 79104, Freiburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Fischer
authors.affiliation: Green Chemistry Centre of Excellence, University of York, Department of Chemistry, Heslington, York, YO10 5DD, UK.
authors.forename: James H
authors.initials: JH
authors.lastname: Clark
mesh_terms: D004058:Diffusion; D005782:Gels; D011134:Polysaccharides / Q000737:chemistry*; D016062:Porosity; D013237:Stereoisomerism; D014270:Trifluoroethanol / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: C528617:1-phenyl-2,2,2-trifluoroethanol; D005782:Gels; D011134:Polysaccharides; D014270:Trifluoroethanol
keywords: chiral; diffusion; polysaccharides; porosity; xerogels