Assembly of nothing: Equilibrium fluids with designed structured porosity

TL;DR

This paper demonstrates how inverse statistical mechanics can be used to design isotropic interactions that assemble particles into fluids with tunable, structured porosity, enabling control over pore size and morphology without external fields.

Contribution

The work introduces a novel inverse design approach to create isotropic pair potentials that produce inhomogeneous fluids with customizable, lattice-like pore structures and diverse microphase morphologies.

Findings

Pore size can be tuned by temperature or concentration.

Multiple microphase-separated morphologies are achievable.

Pore assembly sensitivity depends on the interaction potential form.

Abstract

Controlled micro- to meso-scale porosity is a common materials design goal with possible applications ranging from molecular gas adsorption to particle size selective permeability or solubility. Here, we use inverse methods of statistical mechanics to design an isotropic pair interaction that, in the absence of an external field, assembles particles into an inhomogeneous {\em fluid} matrix surrounding pores of prescribed size ordered in a lattice morphology. The pore size can be tuned via modification of temperature or particle concentration. Moreover, modulating density reveals a rich series of microphase-separated morphologies including pore- or particle-based lattices, pore- or particle-based columns, and bicontinuous or lamellar structures. Sensitivity of pore assembly to the form of the designed interaction potential is explored.