Supramolecular Polymer Frameworks with Controlled and Uniform Pore Apertures.

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Controlled pore structures and tunable apertures in porous materials are highly sought after.
• Precise synthesis of such advanced materials remains a significant challenge in materials science.

Purpose of the Study:

• To develop a method for fabricating 2D supramolecular polymer frameworks with precisely controlled pore sizes.
• To investigate the relationship between polymer backbone length and pore aperture.
• To demonstrate the application of these frameworks in nanomaterial purification and biomacromolecule immobilization.

Main Methods:

• Synthesis of four star-shaped polyisocyanides with varying degrees of polymerization and 2-ureido-4[1H]-pyrimidinone (UPy) terminals.
• Formation of 2D crystalline polymer frameworks via intermolecular hydrogen bonding between UPy units.
• Characterization using small-angle X-ray scattering, atomic force microscopy, and Brunauer-Emmett-Teller analyses.

Main Results:

• Successfully fabricated 2D supramolecular polymer frameworks with uniform hexagonal pores.
• Achieved tunable pore apertures ranging from 5.3 to 19.1 nm, directly correlated with polyisocyanide backbone length.
• Demonstrated effective size-fractionation of silver nanoparticles and enhanced stability and catalytic activity of immobilized myoglobin.

Conclusions:

• The study presents a novel approach for creating well-defined 2D supramolecular polymer frameworks with tunable pore sizes.
• These materials show great promise for applications in separation technologies and biocatalysis.
• The precise control over pore structure opens new avenues for advanced functional materials.