Industrial gas separation, essential for clean energy and environmental protection, demands efficiency and adaptability. Current materials, however, lack the flexibility to selectively separate gases like carbon dioxide (CO₂) and hydrogen (H₂) while remaining energy-efficient. Researchers at the Institute for Integrated Cell-Material Sciences (WPI-iCeMS) at Kyoto University and the Department of Chemical Engineering at National Taiwan University have developed a phase-transformable membrane that could meet these needs.
This innovative membrane design relies on a unique combination of metal-organic polyhedra (MOP) with polyethylene glycol (PEG) chains. "Traditional solid membranes are effective but limited in flexibility, which hinders their efficiency in industrial settings," explains Professor Shuhei Furukawa at Kyoto University, who led the research team. "Our phase-transformable porous materials can be precisely tuned for gas permeability and selectivity by adjusting its physical state." By controlling the temperature, the material can switch between liquid, glass, and crystalline states, optimizing its selectivity and permeability for specific gases.
The membrane's liquid phase is particularly effective for CO₂ capture. In this state, it demonstrates high permeability and selectivity, enabling it to capture CO₂ efficiently from the hydrogen mixture and potentially reduce energy use in capture processes. This characteristic positions it as a promising solution for reducing industrial CO₂ emissions and supporting clean energy production through hydrogen purification.
The versatility of this phase-transformable membrane opens up new possibilities for customizable gas separation. The team envisions a range of applications in which the membrane can be adapted to specific conditions by carefully selecting MOP structures and polymers to fine-tune its properties. This adaptability could allow industries to selectively target various gases under different environmental conditions.
"The next challenge is scaling up production to make this membrane technology feasible for large-scale applications," says Professor Dun-Yen Kang at National Taiwan University. The team is also investigating combinations between MOPs and polymers to widen the scope of gases that can be effectively separated. With further development, this innovative membrane could become a cornerstone in sustainable energy solutions, helping industries meet environmental standards while improving efficiency.
