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 $25^o$. In adsorption experiments a Langmuir type (L) adsorption was found with respect to the Giles classification system. Binding parameters such as initial binding constant ($K_i$), equilibrium constant $(K)$, monolayer coverage (n), site-size (u), and maximum fractional occupancy ($theta$), and thermodynamic parameters such as heat of adsorption ($DeltaH$), free energy of adsorption ($DeltaG$) and entropy of adsorption ($DeltaS$) for the CPVP/BB 1 system were calculated by using Klotz, Scatchard, and Langmuir linearization methods.