Laser Patterning of Porous Support Membranes to Enhance the Effective Surface Area of Thin-Film Composite-Facilitated Transport Membranes for CO2 Separation

Although thin-film composite membranes have achieved great success in CO2 separation, further improvements in the CO2 permeance are required to reduce the size and cost of the CO2 separation process. Herein, we report the fabrication of composite membranes with high CO2 permeability using a laser-patterned porous membrane as the support membrane. High-aspect-ratio micropatterns with well-defined micropores on their surface were carved on microporous polymer supports by a direct laser writing process using a short-pulsed laser. By using a Galvano scanner and optimizing the laser conditions and target materials, in-plane micropatterns, such as microhole arrays, microline grating, microlattices, and out-of-plane hierarchical micropatterns, were created on porous membranes. An aqueous suspension of hydrogel microparticles doped with an amine-based mobile carrier was sprayed onto the patterned surface to form a defect-free thin separation layer. The surface area of the separation layer on the patterned support is up to 80% larger than that of flat pristine membranes, resulting in a 52% higher CO2 permeance (1106 GPU) with a CO2/N2 selectivity of 172. The laser-patterned porous membranes allow the development of inexpensive and high-performance functional membranes not only for CO2 separation but also for other applications, such as water treatment, cell culture, micro-TAS, and membrane reactors.