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

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• Nanoporous materials like zeolites and MOFs are crucial for applications, with embedded mesoporous networks enhancing performance.
• Understanding the relationship between mesoporous structure and fluid transport is challenging due to limitations in current thermodynamic and transport models.

Purpose of the Study:

• To develop a unified framework connecting material structure, thermodynamics, and transport properties in nanoporous solids.
• To resolve the conflict between equilibrium-based thermodynamic models and network-dependent transport phenomena.

Main Methods:

• Leveraging statistical thermodynamics of nonequilibrium-phase states arising from cooperativity in gas adsorption.
• Utilizing structural descriptors of mesopore space, including pore connectivity and hierarchy factor, derived from gas sorption measurements.
• Validating the framework using transmission electron microscopy (TEM), mercury intrusion, and pulsed-field gradient (PFG) NMR experiments.

Main Results:

• A unified framework successfully links nanoporous structure, thermodynamics, and transport properties.
• Cooperative phenomena in gas adsorption, influenced by structural disorder, are key to bridging equilibrium and transport behaviors.
• New structural descriptors accurately predict diffusive transport in materials with homogeneous and hierarchical pore architectures.

Conclusions:

• The developed framework provides a robust method for predicting fluid transport in nanoporous materials.
• Exploiting cooperative phenomena and advanced structural descriptors offers a pathway to optimize material design for enhanced performance.
• This approach advances the understanding and application of complex nanoporous systems.