Stable Zr-UiO-67 constructed through polymeric network assisted post-synthetic modification and its wettability...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Metal-organic frameworks (MOFs) offer tunable properties but often suffer from poor stability in diverse chemical environments.
• Zirconium-based MOFs like UiO-67 are known for their structural robustness but can still be degraded by acidic, alkaline, or saline conditions.
• Developing protective strategies for MOFs is crucial for their practical application in challenging separation processes.

Purpose of the Study:

• To enhance the chemical and environmental stability of Zr-UiO-67 MOFs.
• To impart superlyophobic properties to the modified MOFs for liquid separation applications.
• To investigate the effectiveness of a post-synthetic modification (PSM) strategy using a polymeric network.

Main Methods:

• Post-synthetic modification (PSM) of Zr-UiO-67 using a fluorine-containing polymeric network.
• Characterization of the modified MOFs to confirm the presence and nature of the protective layer.
• Evaluation of the stability of the modified MOFs in acidic, alkaline, and saline aqueous solutions.
• Measurement of the superlyophobic properties, including the surface tension threshold for liquid repellency.

Main Results:

• Successful preparation of stable Zr-UiO-67 through surface modification with a fluorine-containing polymeric layer.
• Demonstrated significant improvement in MOF stability across a range of acidic, alkaline, and saline environments.
• Achieved superlyophobic behavior with a high surface tension threshold (> 48 mN m⁻¹).
• The protective layer effectively shields the MOF structure from chemical attack.

Conclusions:

• The polymeric network-assisted PSM strategy is an effective method for enhancing the stability of Zr-UiO-67.
• The fluorine-containing protective layer confers excellent chemical resistance and superlyophobic properties.
• These stable and superlyophobic MOFs show great potential for advanced liquid-liquid mixture and emulsion separation technologies.