Exploring the Flexibility of MIL-47(V)-Type Materials Using Force Field Molecular Dynamics Simulations

Area of Science:

• Materials Science
• Computational Chemistry
• Solid-State Physics

Background:

• Metal-organic frameworks (MOFs) exhibit tunable properties.
• Understanding the mechanical flexibility of MOFs is crucial for advanced applications.
• MIL-47(V)-type materials are promising candidates due to their unique structures.

Purpose of the Study:

• To investigate the mechanical flexibility of three MIL-47(V)-type materials: MIL-47, COMOC-2, and COMOC-3.
• To construct pressure-volume and free energy-volume profiles at various temperatures.
• To establish a correlation between material structure and mechanical response.

Main Methods:

• Utilized first-principles-based force fields with the QuickFF parametrization protocol.
• Developed specific terms to model the asymmetry of vanadium-oxide chains and linker flexibility.
• Performed molecular dynamics simulations at varying unit cell shapes and fixed volumes.

Main Results:

• The three MIL-47(V)-type materials exhibited distinct pressure-volume behaviors.
• Temperature variations (100–400 K) influenced the mechanical response.
• The study successfully modeled the flexibility of the one-dimensional vanadium-oxide chain and organic linkers.

Conclusions:

• The mechanical properties of MIL-47(V)-type materials can be effectively tuned by modifying organic linkers.
• These materials demonstrate potential for applications requiring specific mechanical responses, such as nanosprings, dampers, and shock absorbers.
• The QuickFF protocol provides a reliable method for simulating the flexibility of MOFs.