Three-Dimensional Mesoporous Covalent Organic Frameworks through Steric Hindrance Engineering.

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Three-dimensional (3D) covalent organic frameworks (COFs) are crucial for advanced applications.
• Challenges include structural interpenetration and pore collapse, limiting pore size and stability.
• Developing 3D COFs with large pores and high surface areas remains a significant hurdle.

Purpose of the Study:

• To introduce a general method for synthesizing non-interpenetrated 3D COFs with large mesopores.
• To overcome limitations of conventional COFs regarding pore size and structural integrity.
• To explore new avenues for creating advanced COFs for adsorption and separation.

Main Methods:

• Steric hindrance engineering by strategic placement of methoxy and methyl groups on monomers.
• Synthesis of novel 3D COFs with diamondoid structures.
• Characterization of pore size, surface area, and structural stability.

Main Results:

• Successfully synthesized a series of non-interpenetrated 3D mesoporous COFs.
• Achieved permanent mesopores up to 26.5 Å and high surface areas exceeding 3000 m² g⁻¹.
• Demonstrated superior performance compared to conventional COFs with similar topologies.

Conclusions:

• Steric hindrance engineering is an effective strategy for creating robust, large-pore 3D COFs.
• The developed COFs offer significant potential for adsorbing and separating large molecules.
• This work paves the way for new applications in molecular separation and storage.