Tianjin – October 13, 2026 -- Researchers at Tianjin University have developed an all-organic mixed-matrix membrane that raised CO2 permeability by an order of magnitude in simulated flue gas tests, a new record, with a preliminary capture cost estimate of about $38 per tonne of CO2.
The study appeared online in Nature Energy on Oct. 7 under the title "All-organic mixed-matrix membranes with single-crystal covalent organic frameworks for carbon capture."
Weak-interaction inlaying targets the filler-polymer compatibility problem
Mixed-matrix membranes pair the processability of polymers with the molecular transport of porous fillers. Development has been limited by compatibility problems between the two components. Porous particles can aggregate or settle within the polymer. Overly strong filler-polymer interactions can restrict polymer movement or block transport pathways.
The team, led by professors Jiang Zhongyi and He Guangwei, proposed a "weak-interaction inlaying" strategy. Rather than strengthening filler-polymer bonds, it balances those interactions against the interactions among filler particles.
Single-crystal COF fillers achieve uniform high loading
Using single-crystal covalent organic frameworks (COFs) as the porous filler, the researchers achieved uniform incorporation at high loading. The membrane kept the polymer's flexibility and solution processability. The ordered COF pores provided efficient CO2 transport pathways.
Membrane holds performance amid water vapor, sulfur oxides and nitrogen oxides
In simulated flue gas tests, performance stayed consistent during extended operation. It also held up under conditions containing water vapor, sulfur oxides and nitrogen oxides, which are common challenges for CO2 separation from industrial flue gas.
A preliminary techno-economic analysis put capture cost at about $38 per tonne of CO2 under the study's assumptions.
The researchers identified potential future applications in carbon capture from power generation, cement and steel production.