Multiple Amine-Contained POSS-Functionalized Organosilica Membranes for Gas Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Organosilica materials are crucial for gas separation membranes.
• Polyhedral oligomeric silsesquioxanes (POSS) offer tunable properties for nanocomposite applications.
• Mixed matrix membranes (MMMs) combine the advantages of polymer and inorganic materials for enhanced separation.

Purpose of the Study:

• To synthesize and characterize a novel POSS-based nanocomposite for gas separation membranes.
• To investigate the effect of POSS incorporation on the structure and gas transport properties of organosilica membranes.
• To compare the performance of POSS-based MMMs with traditional hybrid membranes for CO2/N2 separation.

Main Methods:

• Synthesis of a novel POSS with eight amine-containing groups (PNEN).
• Preparation of mixed matrix membranes (MMMs) by incorporating BTESE-PNEN nanocomposites into an organosilica matrix.
• Characterization using thermogravimetric analysis (TGA) and gas permeance measurements.
• Evaluation of membrane pore size using a modified gas-translation model.
• Comparative study with hybrid membranes prepared using 3-aminopropyltriethoxysilane (APTES).

Main Results:

• Uniform BTESE-PNEN mixtures with particle sizes around 31 nm were achieved.
• The membranes exhibited good thermal stability.
• BTESE-PNEN membranes showed larger pore sizes compared to BTESE-APTES hybrid membranes at similar additive concentrations.
• The separation performance, particularly for CO2/N2, indicated potential for CO2 separation.

Conclusions:

• The incorporation of PNEN-functionalized POSS into BTESE-derived organosilica creates effective MMMs for gas separation.
• The modified pore structure in BTESE-PNEN membranes influences gas transport properties.
• This strategy demonstrates the potential of using amine-functionalized POSS as particles in MMMs for CO2 separation applications.