Kinetics of nicotine bonding onto and release from poly (acrylic -co-methacrylic acid) hydrogel

Abstract

The isothermal kinetics of nicotine bonding from aqueous solutions onto poly(acrylic-co-methacrylic acid) xerogel/hydrogel and the release of binded nicotine from the same xerogel in distilled water were investigated. The isothermal kinetic curve of nicotine bonding and the release to/or from PAM hydrogel were determined at a temperature range of 294- 314 K. By applying the method of model fitting, it was established that the isothermal kinetics of nicotine bonding at xerogel/hydrogel can be described by the kinetics model of two dimensional diffusion (D-2), whereas the kinetics of nicotine release is best described by the kinetics model of tridimensional contracting area (R-3). The values of kinetic parameters (Ea and lnA) of nicotine bonding (Ea = 10 kJmol-1; ln[A/min-1] =1.62) and nicotine release (Ea = 28 kJmol-1; ln[A/min-1] = 8.0) were determined. By applying the differential isoconversional method, it was established that both nicotine bonding and release are kinetically complex processes. The new models for the mechanism of nicotine bonding and release were proposed and suggested. The functions of density distribution Ea, α. of nicotine bonding and release were calculated and are presented here. The established kinetics model of bonding and release and their kinetic parameters are explained with the suggested models of the mechanism of nicotine bonding and release, and with the specific shapes of the density distribution functions. © 2012 by Nova Science Publishers, Inc. All rights reserved.