Microporous Polymers with Heterocyclic Rings for Gas Separation Membranes

Tech ID: 20-052

Inventor: Dr. Ruilan Guo

Date added: June 29, 2020


Microporous polymer membranes containing hierarchical bulky units that achieve superior gas separation performance with ultrahigh permeability and selectivity. 

Technology Summary

The market of gas separation membranes has been growing at 7-8% per year since the 1980s, projected to be a $2.61 billion industry by 2022. Traditionally, gas separation used technologies such as pressure swing absorption and cryogenic distillation, which require a significant amount of energy and space to effectively separate various gasses. In order to reduce energy and space requirements, membrane separation technology has recently been implemented. One of the leading gas separation membrane materials involve highly rigid polymers with heterocyclic rings, as represented by polybenzoxazoles (PBOs) derived from thermal rearrangement (TR) of ortho-functional polyimide precursors. However, most of the reported TR membranes possess less attractive selectivity compared to their generally ultrahigh permeability due to the lack of fine tuning in microporosity or ultramicroporosity. Additionally, state-of-the-art microporous polymers such as PIMs (polymers with intrinsic microporosity) have poor resistance to physical aging and plasticization due to large fractional free volume and the flexibility at the spirocenter of the backbone. Therefore, a new kind of microporous polymer membranes with superior size sieving, increased permeability without sacrificing specificity, and increased resistance to physical aging and plasticization is necessary to improve the current state of gas separation via membranes. 

Researchers at the University of Notre Dame have recently developed a novel microporous polymer membrane containing bulky, shape-persistent pentiptycene units, which show superior gas separation performance with ultrahigh gas permeability and selectivity. The technology introduces hierarchical iptycene-based structure units into TR polymer backbone structures, enabling superior size sieving through the internal free volume elements originated from the molecular configuration of iptycene unit. The properties of the membranes can be tuned by varying the precursor composition, functionality, and thermal protocols. The microporous polymers with heterocyclic rings for gas separation membranes developed by the University of Notre Dame is a better alternative than the state-of-the-art membranes because the membranes are easy to fabricate, resist plasticization, and have very high selectivity and permeability. 

Market Advantages

•    Superior gas separation performance due to ultrahigh gas permeabilities and selectivity not limited by the conventional permeability and selectivity trade-off. 
•    Excellent resistance toward physical aging and plasticization. 
•    Easily tunable membranes to deliver tailored microstructure and consequent membrane properties. 

Market Opportunity

•    Wide range of separation applications such as natural gas purification (CO2/CH4), hydrogen separation/purification (H2/CH4, H2/CO2, H2/N2), carbon capture (CO2/N2), and air separation (O2/N2).
•    Potential to be expanded to other challenging separations such as separations of light hydrocarbons and organic solvent filtration. 

Technology Readiness Status

TRL 4 - Lab Validation


Richard Cox