Stabilizing Covalent Organic Frameworks through Hydrogen Bonding Bridges for Polyamine Entanglement toward Carbon...

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Incorporating polyamines into covalent organic frameworks (COFs) is key for developing effective carbon capture adsorbents.
• Maintaining the crystallinity and porosity of COFs during this process is crucial but challenging.

Purpose of the Study:

• To develop a strategy for stabilizing COF structure during polyamine functionalization for carbon capture.
• To investigate the role of hydrogen bonding in preserving COF crystallinity and porosity.

Main Methods:

• Utilized a hydrogen bonding (HB) bridge strategy during in situ free radical polymerization to functionalize a 2D mesoporous COF (NUS-43) with polyamines.
• Employed techniques including PXRD, ssNMR, FTIR, and DFT calculations to confirm structural stabilization.
• Evaluated CO2 capture performance under simulated conditions and characterized adsorption/degradation mechanisms.

Main Results:

• The HB bridge strategy successfully maintained the crystallinity and porosity of the NUS-43 COF during polyamine incorporation.
• Functionalized COFs (NUS-43-VBA/VEA) demonstrated significant CO2 uptake (0.5-0.6 mmol g⁻¹) under various conditions.
• FTIR and ssNMR spectroscopy provided insights into CO2 adsorption and amine oxidative degradation mechanisms.

Conclusions:

• Hydrogen bonding is critical for stabilizing 2D COFs during polyamine incorporation, preventing structural degradation.
• The developed method offers a robust approach for creating high-performance CO2 adsorbents.
• This study enhances understanding of amine-based carbon capture mechanisms and material stability.