Robust and Elastic Polymer Membranes with Tunable Properties for Gas Separation

Area of Science:

• Materials Science
• Polymer Chemistry
• Chemical Engineering

Background:

• Polymer membranes are crucial for gas separation, but their performance is limited by mechanical weakness, plasticization, and aging.
• Elastic polymer membranes with tunable mechanical properties are gaining attention for advanced applications.

Purpose of the Study:

• To develop novel urethane-rich polydimethylsiloxane-based polymer networks (U-PDMS-NW) with improved mechanical performance for gas separation.
• To investigate the relationship between cross-link density and mechanical/gas separation properties.

Main Methods:

• Synthesized U-PDMS-NW by varying the molecular weight of PDMS to control cross-link density.
• Characterized mechanical properties including elongation, Young's modulus, tensile strength, and toughness.
• Evaluated gas separation performance, thermal resistance, and aging tolerance.

Main Results:

• U-PDMS-NW demonstrated up to 400% elongation and tunable mechanical properties (Young's modulus: 1.3-122.2 MPa, tensile strength: 1.1-14.3 MPa, toughness: 0.7-24.9 MJ/m³).
• Achieved high gas permeability (>100 Barrer) and tunable selectivity (α[PCO/PN] ≈ 41, α[PCO/PCH] ≈ 16).
• Exhibited excellent thermal resistance and aging tolerance.

Conclusions:

• U-PDMS-NW offer a promising platform for high-performance gas separation membranes due to their superior mechanical properties and gas transport characteristics.
• The tunable nature of U-PDMS-NW makes them suitable for diverse applications beyond gas separation, including microfluidics and stretchable electronics.