Phase behaviour of a simple fluid confined in a periodic porous material

Using density functional theory for a simple fluid of hard spheres with a square-well attraction, we study the phase behaviour of the fluid confined in triply periodic porous material, where the pore space is bounded by a bicontinuous minimal surface. We combine our numerical results with the morphometric thermodynamics, an ansatz that expresses thermodynamic quantities as a linear combination of four additive geometrical terms, and analyse the dependency of the transition point between a liquid and a gas on the geometrical properties of the confining space. By demonstrating that the morphometric approach can be employed in order to account for the thermodynamic behaviour of a simple fluid in a complex porous material, we make the first step towards a better understanding of experimental observations that can help to characterise the pore space.

Automated summary

This study investigates the phase behavior of a simple fluid of hard spheres with a square-well attraction confined in triply periodic porous material, using density functional theory. By combining numerical results with morphometric thermodynamics, the dependency of the transition point between liquid and gas on the geometrical properties of the confining space is analyzed. The research demonstrates the potential of employing the morphometric approach to better understand the thermodynamic behavior of a simple fluid in complex porous materials, taking the first step towards characterizing experimental observations of pore space.