A comparison of adsorption isotherms of crosslinked poly(N-vinylpyrrolidone)/basic brown 1 binding system

Abstract

In this study, the binding of a basic dye such as basic brown 1 [BB 1] onto a crosslinked poly(N-vinylpyrrolidone) [CPVP] was investigated. Adsorption of the azo dye onto the CPVP was studied by the batch adsorption technique at 25°C. In adsorption experiments a Langmuir type (L) adsorption was found with respect to the Giles classification system. Binding parameters such as initial binding constant (Ki), equilibrium constant (K), monolayer coverage (n), site-size (u), and maximum fractional occupancy (??), and thermodynamic parameters such as heat of adsorption (?H), free energy of adsorption (?G) and entropy of adsorption (?S) for the CPVP/BB 1 system were calculated by using Klotz, Scatchard, and Langmuir linearization methods.