# Predicting Structure and Transport in Disordered Mesoporous Materials via Cooperative Phase Transitions

## TL;DR

This paper introduces a new framework to predict transport in disordered mesoporous materials by linking structure, thermodynamics, and cooperative phase transitions.

## Contribution

A unified framework that connects mesopore structure, thermodynamics, and transport via cooperative phenomena in gas adsorption.

## Key findings

- Structural descriptors like average pore connectivity and hierarchy factor predict diffusive transport accurately.
- The framework works for both homogeneous and hierarchical mesoporous materials.
- Validation was done using TEM, mercury intrusion, and PFG NMR experiments.

## Abstract

The interplay between
material structure, thermodynamics, and transport
of confined fluids in nanoporous solids underpins their practical
applications. Mesoporous networks embedded within microporous frameworks
of zeolites and MOF materials are attracting increasing attention
as they can enhance material properties and boost their performance.
Correlating the mesoporous network structure with transport properties,
however, remains challenging due to an apparent conflict: most thermodynamic
models focus on single-pore equilibrium behavior, whereas transport
is largely dictated by the organization of the pore network. Herein,
we show that exploiting cooperative phenomena in gas adsorption governed
by structural disorder resolves this challenge. We present a unified
framework that links the structure, thermodynamics, and transport
by leveraging recent advances in the statistical thermodynamic description
of nonequilibrium-phase states arising from cooperativity across pore
networks. Structural descriptors of the mesopore space, extractable
from gas sorption measurements including, beyond conventional pore
size distributions, the average pore connectivity and a hierarchy
factor describing deviations from a fully random structure, are used
to accurately predict diffusive transport. The framework’s
robustness is validated for mesoporous materials with both homogeneous
and hierarchical pore architectures through experiments using transmission
electron microscopy (TEM), mercury intrusion, and pulsed-field gradient
(PFG) NMR.