Kinetics and Adsorption Isotherm of Ibuprofen onto Grafted β-CD/Chitosan Polymer

Abstract

The adsorption of the Ibuprofen (Ibu) drug on β-cyclodextrin (β-CD) grafted chitosan polymer was studied under different experimental conditions. The effect of Ibu concentration, mass of β-CD grafted chitosan polymer as adsorbent, contact time, temperature and pH were investigated. Three equilibrium models, Langmuier, Freundlich and Temkin isotherm models were analyzed to evaluate the adsorption isotherms. The adsorption isotherms were best fitted by Freundlich isotherm model, with correlation coefficient 0.9882, the intensity of adsorption parameters was lower than one and Freundlich adsorption isotherm constant value was more than one. High adsorption was found in acidic media pH 2, 27°C and 1 h adsorption time. In order to investigate the kinetic of the adsorption process four kinetic models were analyzed, pseudo first order kinetic model, pseudo second order kinetic model, the Elovich kinetic model and intraparticle diffusion kinetic model. Kinetic parameters include; binding strength constant, first order adsorption rate constant, intraparticle diffusion rate constant, adsorption half time, rate constant, equilibrium constant and adsorption capacities. Correlation coefficient for each kinetic equation was reported. The adsorption kinetics was best fitted by pseudo-first order kinetic equation, with correlation coefficient 0.9922. The rate determining step is well described by intraparticle diffusion process. The Intraparticle diffusion rate constant values ranging from 0.163 to 1.1441 mgg^-1 min^-1/2