Abstract
Polymer membranes with the capability to process a massive volume of gas are especially attractive for practical applications of gas separation. Although much effort has been devoted to develop novel polymer membranes with
increased selectivity, the overall gas-separation performance and lifetime of membrane are still negatively affected by the weak mechanical performance, low plasticization resistance and poor physical aging tolerance. Recently, elastic polymer membranes with tunable mechanical properties have been attracting significant attentions due to their tremendous potential applications. Herein, we report a series of urethanerich PDMS-based polymer networks (U-PDMS-NW) with improved mechanical performance for gas separation. The cross-link density of U-PDMS-NWs is tailored by varying the molecular weight (Mn) of PDMS. The U-PDMS-NWs show up to
400% elongation and tunable Young’s modulus (1.3−122.2 MPa), ultimate tensile strength (1.1−14.3 MPa), and toughness (0.7−24.9 MJ/m3). All of the U-PDMS-NWs exhibit salient gas-separation performance with excellent thermal resistance and aging tolerance, high gas permeability (>100 Barrer), and tunable gas selectivity (up to α[PCO2/PN2] ≈ 41 and α[PCO2/PCH4] ≈ 16). With well-controlled mechanical properties and gas-separation performance, these U-PDMS-NW can be used as a polymermembrane platform not only for gas separation but also for other applications such as microfluidic channels and stretchable electronic devices.
