title: The aggregation behavior of O-carboxymethylchitosan in dilute aqueous solution.
abstract: O-Carboxymethylchitosan (OCMCS) is a kind of biocompatible derivatives of chitosan whose water solubility is strongly dependent on the degree of carboxymethylation. The OCMCS with 100 carboxymethyl groups and 75 amino groups per 100 anhydroglucosamine units of OCMCS was synthesized by the reaction of chitosan and monochloroacetic. When OCMCS was dissolved in water, its solution was neutral and OCMCS behaved like a weak polyanionic polyeclectrolyte because most of carboxylic groups were not dissociated in neutral aqueous solution. The aggregation behavior of OCMCS in aqueous solution was studied by surface tensiometry, steady-state fluorescence spectroscopy and viscometry. The critical aggregation concentration (cac) of OCMCS was determined to be between 0.042 mg/ml and 0.050 mg/ml. The possible aggregation mechanism of OCMCS in water was elucidated.
authors.affiliation: College of Chemical and Chemical Engineering, Yangzhou University, Yangzhou 225009, PR China. zapyz@yahoo.com
authors.forename: Aiping
authors.initials: A
authors.lastname: Zhu
authors.forename: Mary B
authors.initials: MB
authors.lastname: Chan-Park
authors.forename: Sheng
authors.initials: S
authors.lastname: Dai
authors.forename: Lin
authors.initials: L
authors.lastname: Li
mesh_terms: D001672:Biocompatible Materials; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D048271:Chitosan / Q000737:chemistry*; D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D012996:Solutions; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship; D013500:Surface Tension; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D012996:Solutions; C426873:mono-N-carboxymethylchitosan; D048271:Chitosan