Designing Bifunctional Ionic Porous Polymers: Impact of Secondary Building Blocks on Wastewater Remediation and Antibacterial Efficiency

In recent years, ionic porous organic polymers (iPOPs) have emerged as a versatile class of materials, offering a unique combination of tunable porosity, high surface area, and physicochemical stability with charged skeletons, which enhances their functionality for diverse applications. However, their structural property relationship, which could be a decisive factor in designing high-performing ionic porous organic polymers, remains largely unexplored. Herein, we report the synthesis of three iPOPs (iPOP-IMZ-1, iPOP-IMZ-2, and iPOP-IMZ-3) using guanidinium-based primary building blocks and varying secondary building blocks to modulate charge density and optimize performance. The cationic polymers exhibited excellent adsorption capabilities for toxic oxo-anions and anionic dyes, addressing critical wastewater pollutants. Furthermore, their antibacterial properties were demonstrated via the membrane disruption of bacterial cells, highlighting their dual functionality. Scanning electron microscopy imaging suggested that the polymers exert their activity via a membrane disruption mechanism of action. This study provides insights into the structure–property relationship of iPOPs, emphasizing the critical role of secondary building blocks in tuning the material performance. These findings establish iPOPs as promising multifunctional materials for environmental remediation and antibacterial applications.