A Universal Approach Using Water-Soluble Templates for Meso- and Macro-Porous Organic Polymers

Porous functional organic polymers have attracted significant interest due to their diverse applications in adsorption/separation, electrocatalysis, photocatalysis, photosensing, and electronics. In these applications, performance depends on interactions between guest molecules and polymer frameworks. Consequently, the introduction of mesopores (2-50 nm) and macropores (50-300 nm) can significantly enhance functionality by simultaneously increasing the exposed active surface area and facilitating molecular diffusion within the polymer matrix. However, a wide range of porous polymers achievable through previous approaches, including surfactant and polystyrene templating, has been severely limited to a few less functional polymers due to the typically aqueous environment used during templating reaction and the need for template removal after polymerization. In this work, a universal approach is demonstrated that utilizes water-soluble templates to synthesize functional meso- and macro-porous organic polymers via solid-state polymerization of aldehydes and amines (Schiff reaction), using perovskite metal fluorides (KMF₃) as sacrificial templates. By precisely tuning the particle sizes of metal fluoride templates, accurate control over pore sizes across the mesoscopic and macroscopic scales is achieved. A variety of aldehyde-amine combinations yield semiconductive meso- and macro-porous organic polymers. This versatile synthetic strategy is broadly applicable to a wide range of polymer systems, enabling simultaneous enhancement of surface area and molecular diffusion, thereby optimizing functional performance.