Evaluation of Microporosity, Pore Tortuosity, and Connectivity of Montmorillonite Solids Pillared with LaNiO<i>_x</i> Binary Oxide. A Combined Application of the CPSM Model, the α_s-Plot Method and a Pore Percolation−Connectivity Model

Abstract

The present work deals with the comparative application of the CPSM (corrugated pore structure model), the α s plot and the pore connectivity methods for pore structure analysis and especially the detection of microporosity of a category of montmorillonite clays pillared with LaNiO x binary oxide. A quite good agreement between the corresponding results deduced from the three methods was confirmed. The raising of the LaNiO x content caused a change of pore volume, surface area, and microporosity whereas the relevant curves pass through a maximum. The CPSM model, through the simulation of gas sorption hysteresis, enables the evaluation of unified mesomicropore size distributions, pore surface areas, tortuosity factors, τ CPSM, and relative microporosities. It is also concluded that pore tortuosity, (τ CPSM ), is inversely proportional to the pore connectivity factor ( c ), and the nominal pore length ( N s ) (i.e., a CPSM parameter) is proportional to the number of pore lengths ( L ) (i.e., a parameter of the pore connectivity model).