title: Cationic-modified cyclodextrin nanosphere/anionic polymer as flocculation/sorption systems.
abstract: Simultaneous removal of dissolved and colloidal substances has been a challenging task. The cationic-modified beta-cyclodextrin nanospheres synthesized in this work, in conjunction with a water-soluble polyacrylamide-based anionic polymer, potentially provide a novel approach to address the problem. The cyclodextrin was rendered cationic using (2,3-epoxypropyl)trimethylammonium chloride as a reagent. The cationicity of the modified cyclodextrin and the reaction between cyclodextrin and the reagent were characterized by electrophoresis measurement, polyelectrolyte titration, and NMR. As a dual-component flocculation system, the cationic cyclodextrin/anionic polymer significantly induced clay flocculation, lowering the relative turbidity of the clay suspension over a wide pH range. Meanwhile, as a nanospherical absorbent, the modified cyclodextrins exhibited strong affinity toward aromatic compounds via inclusion complex formation in the hydrophobic cavities, which was monitored by UV spectroscopy. These systems facilitated the simultaneous removal of dissolved and colloidal substances, which was unachievable previously. In addition, the interaction between anionic polymers and the clay particles pretreated with cationic cyclodextrin was investigated in order to reveal the flocculation mechanism.
authors.affiliation: Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada. hxiao@unb.ca
authors.forename: Huining
authors.initials: H
authors.lastname: Xiao
authors.forename: Norlito
authors.initials: N
authors.lastname: Cezar
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000838:Anions / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D003102:Colloids / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D009994:Osmolar Concentration; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D047392:beta-Cyclodextrins / Q000138:chemical synthesis / Q000737:chemistry*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D000838:Anions; D002412:Cations; D003102:Colloids; D004852:Epoxy Compounds; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D047392:beta-Cyclodextrins; D000099166:Polyacrylamides; C045006:glycidyl trimethylammonium; C031215:betadex