A General Group-Protection Synthesis Strategy to Fabricate Covalent Organic Framework Gels

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Fabricating insoluble and infusible porous materials into gels presents significant challenges for advanced applications.
• Covalent Organic Frameworks (COFs) offer tunable properties but are difficult to process into gel forms.

Purpose of the Study:

• To develop a general, facile, and scalable protocol for fabricating covalent organic framework (COF) gels.
• To demonstrate the versatility and tunable properties of these COF gels for diverse applications.

Main Methods:

• Utilized a group-protection synthesis strategy to control COF formation.
• Prepared 10 types of COF organohydrogels, investigating their structural and mechanical properties.
• Analyzed the role of solvent and functional groups in gel formation and stability through mechanistic studies.

Main Results:

• Successfully fabricated 10 types of COF organohydrogels with high crystallinity, porosity, and mechanical strength.
• Demonstrated excellent solvent and freezing resistance, with easy transformation into hydrogels, organogels, and aerogels.
• Unveiled that the group-protection strategy regulates COF morphology and hydrogen bonding networks are crucial for gel stability and properties.

Conclusions:

• The group-protection strategy provides a versatile toolkit for synthesizing COF gels with tunable properties.
• COF gels exhibit remarkable stability and transformability, expanding their potential applications.
• COF gels functionalized with azobenzene groups show promise for solar desalination due to efficient solar energy absorption and conversion.