title: Equilibrium and kinetic aspects of sodium cromoglycate adsorption on chitosan: mass uptake and surface charging considerations.
abstract: Chitosan has more and more been suggested as a material for use as adsorbent in the treatment of effluents as well as in the synthesis of drug-loaded nanoparticles for controlled release. In both cases, a good understanding of the process of adsorption, both kinetically and in terms of equilibrium, has an importance of its own. In this manuscript we study the interaction between sodium cromoglycate, a drug used in asthma treatment, and chitosan. Equilibrium experiments showed that Sips (or Freundlich-Langmuir) isotherm described well the resultant data and adsorption possibly occurred as in multilayers. A model based on ordinary reaction-rate theory, compounded of two processes, each one with a correlated velocity constant, described the kinetics of sorption. Kinetic and equilibrium data suggested the possibility of surface rearrangement, favored by the increase of temperature.
authors.affiliation: Instituto de Química, Universidade Federal do Rio Grande do Norte, Campus Universitário, Lagoa Nova, Natal, RN 59078-970, Brazil.
authors.forename: C R M
authors.initials: CR
authors.lastname: de Lima
authors.forename: M R
authors.initials: MR
authors.lastname: Pereira
authors.forename: J L C
authors.initials: JL
authors.lastname: Fonseca
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D004205:Cromolyn Sodium / Q000737:chemistry*; D007700:Kinetics; D015394:Molecular Structure; D013499:Surface Properties
chemical_list: D048271:Chitosan; D004205:Cromolyn Sodium