Controlling Dissolution and Transformation of Zeolitic Imidazolate Frameworks by using Electron-Beam-Induced...

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Amorphous zeolitic imidazolate frameworks (ZIFs) are emerging functional materials with unique properties.
• Controlling the stability and morphology of ZIFs is crucial for their practical applications.

Purpose of the Study:

• To investigate the amorphization of ZIF-L using scanning electron beam exposure.
• To evaluate the impact of amorphization on the water stability and morphology of ZIFs.
• To explore the potential of electron beam lithography for MOF patterning.

Main Methods:

• Amorphization of individual ZIF-L crystals via scanning electron beam exposure.
• Assessment of water stability of amorphized ZIFs through immersion tests.
• Characterization of morphology and spatial control at the sub-micrometer scale.
• Demonstration of amorphization and stability changes in ZIF-8, Zn(BeIm)OAc, and MIL-101.
• Study of recrystallization behavior in crystalline and amorphized ZIF-L.

Main Results:

• Electron beam exposure successfully amorphized ZIF-L, significantly increasing its water stability.
• A specific electron dose was identified for preserving amorphous ZIF-L particles in water.
• Spatial control over amorphous ZIF-L shapes at the sub-micrometer level was achieved.
• Similar water stability enhancements were observed for other metal-organic frameworks (MOFs).
• Recrystallization processes differed between crystalline and amorphized ZIF-L.

Conclusions:

• Scanning electron beam exposure is an effective method for amorphizing ZIFs and enhancing their water stability.
• This technique offers precise control over MOF morphology for potential top-down patterning applications.
• The findings open new avenues for designing robust and shape-controllable ZIF-based functional materials.