Vibration assisted glass-formation in zeolitic imidazolate framework

Area of Science:

• Materials Science
• Chemistry

Background:

• Conventional melt-quenching methods limit the production of glassy metal-organic frameworks (MOFs).
• Developing new glass-forming techniques is crucial for expanding the applications of glassy MOFs.

Purpose of the Study:

• To introduce a novel in situ mechanical vibration method for producing glassy MOFs.
• To investigate the properties of MOF glasses produced by this new method.

Main Methods:

• Utilizing zeolitic imidazolate framework (ZIF)-62 as a model material.
• Applying in situ mechanical vibration to facilitate low-temperature melting.
• Characterizing the resulting glassy MOFs, including glass transition temperature and porosity.

Main Results:

• In situ mechanical vibration enabled melting of ZIF-62 at 653 K, significantly below its melting point of 713 K.
• The vibrated ZIF-62 glass exhibited a lower glass transition temperature (545 K), improved gas accessible porosity, and distinct structural features.
• The proposed mechanism involves vibration-facilitated surface reconstruction leading to pre-melting.

Conclusions:

• In situ mechanical vibration is a viable and general method for producing MOF glasses without thermal decomposition.
• This technique offers a pathway to novel glassy MOFs with tailored properties.
• The findings broaden the scope of MOF glass formation and potential applications.