S/N/O-Enriched Carbons from Polyacrylonitrile-Based Block Copolymers for Selective Separation of Gas Streams.

Area of Science:

• Materials Science
• Polymer Chemistry
• Carbon Materials

Background:

• Polyacrylonitrile (PAN)-based block copolymers are effective precursors for porous carbon synthesis.
• Controlling porosity and surface chemistry is crucial for carbon applications, particularly in gas separation.
• Sacrificial blocks and post-synthesis modifications offer tunable routes to desired carbon properties.

Purpose of the Study:

• To synthesize porous carbons using PAN-PMMA block copolymers as precursors.
• To investigate the effect of sulfur incorporation and copolymer composition on carbon structure and porosity.
• To evaluate the performance of the synthesized carbons for N₂/CO₂ separation in post-combustion applications.

Main Methods:

• Synthesis of polyacrylonitrile (PAN)-poly(methyl methacrylate) (PMMA) block copolymers via atom transfer radical polymerization.
• Preparation of porous carbons from PAN-PMMA precursors through controlled oxidation and sulfuration.
• Characterization using Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS), and volumetric gas adsorption analysis.
• Testing carbon performance for N₂/CO₂ separation.

Main Results:

• Sulfur incorporation shifted carbon structure from microporous to mesoporous.
• Varying PAN/PMMA molar ratios (10/90 to 47/53) controlled carbon porosity.
• The sacrificial PMMA block influenced nanostructuration in oxygen-stabilized carbons but not chemical composition.
• Synthesized carbons demonstrated suitability for separating N₂/CO₂ from post-combustion flue gas.

Conclusions:

• PAN-PMMA block copolymers are versatile precursors for tailored porous carbon synthesis.
• Sulfur functionalization and controlled copolymer composition are key to achieving desired porosity and structure.
• The resulting porous carbons show promise for post-combustion CO₂ capture applications.