Accuracy of dubinin-astakhov and dubinin-radushkevich adsorption isotherm models in evaluating micropore volume of bentonite

Abstract

Accuracy of Dubinin-Astakhov (DA) and Dubinin-Radushkevich (DR) isotherm models were examined for evaluating micropore volume of several natural and pillared bentonite samples with type I and II isotherms. Afterwards, the obtained results were compared with the micropore volume calculated by Horvath–Kawazoe (HK) model. The results showed that the accuracy of DA and DR models for this purpose depends on isotherm types and range of relative pressure (P/P0) in which the models are applied. It can be generally concluded that DA and DR can be used to calculate micropore volume of bentonite instead of HK which imposes more complicated calculations.