Effect of VTMS-Modified TiO₂ Nanoparticles on CO₂ Separation Performance of Polysulfone-Based Mixed Matrix Membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Polysulfone (PSF) membranes show limitations in gas separation performance and filler compatibility.
• Interfacial voids and defects hinder the efficiency of traditional mixed matrix membranes (MMMs).

Purpose of the Study:

• To enhance polysulfone (PSF) mixed matrix membranes (MMMs) for selective carbon dioxide (CO2)/nitrogen (N2) separation.
• To improve filler dispersion and interfacial adhesion using vinyltrimethoxysilane (VTMS)-functionalized TiO2 nanoparticles.

Main Methods:

• Fabrication of MMMs with varying VTMS@TiO2 loadings (1-5 wt.%) via solution casting.
• Characterization using SEM, FTIR, XRD, and TGA to confirm VTMS modification and dispersion.
• Systematic evaluation of gas separation performance (CO2 permeability and CO2/N2 selectivity).

Main Results:

• VTMS modification of TiO2 nanoparticles improved their dispersion and interfacial adhesion within the PSF matrix.
• The membrane with 4 wt.% VTMS@TiO2 exhibited optimal performance: 8.48 barrer CO2 permeability and 26.50 CO2/N2 selectivity.
• Optimized membrane approached the Robeson upper bound, indicating superior gas separation capabilities compared to pure PSF.

Conclusions:

• VTMS-functionalized TiO2 nanoparticles effectively enhance MMMs for CO2/N2 separation.
• Improved filler dispersion, interfacial integrity, and CO2 affinity contribute to enhanced membrane performance.
• The developed MMMs offer a promising solution for efficient and selective CO2 capture.