| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 600076 | Colloids and Surfaces B: Biointerfaces | 2013 | 7 Pages |
•Cromoglycate ion is adsorbed on chitosan by electrostatic or hydrophobic interactions.•Adsorption isotherms show that below a critical temperature, hydrophobic interactions prevail.•Sorption kinetics may be divided into slow and fast processes.•Slow processes are related to the mobility of groups on chitosan surface.•Fast processes are related to the adsorption of cromoglycate on chitosan.
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.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
