Poromechanics of adsorption-induced swelling in microporous materials: a new poromechanical model taking into account strain effects on adsorption

A poromechanical model is presented for estimating swelling of nano-porous media fully saturated with a fluid phase. From the Gibbs adsorption isotherm, the effective pore pressure and the volumetric strain are estimated incrementally taking into account the variations of porosity upon swelling and therefore the variations of the poromechanical properties (apparent modulus, Biot coefficient, Biot modulus). Moreover, the interaction between swelling and the adsorption isotherms are examined by proposing a correction to the Gibbs formalism by taking into account the pore volume variation upon swelling. First, comparisons with experimental data found in the literature are performed, and a fair agreement is observed.