Enhancing tetracycline adsorption capacity of phenolic hydroxyl-functionalized hyper-crosslinked polymers through synergistic porosity-accessibility strategy

Tetracycline (TC) contamination in aquatic environments poses severe ecological and health risks, necessitating the development of high-performance adsorbents. Focusing on resolving the poor accessibility and inadequate pore architectures of phenolic hydroxyl-functionalized hyper-cross-linked polymers (HCPs), we proposed a copolymerization strategy to synthesize several HCPs with resorcinol and benzene as monomers. By optimizing their molar ratio, a synergistic enhancement of specific surface area, hierarchical porosity, and accessibility were realized. The optimal HCP-B3 exhibited an exceptional TC adsorption capacity of 441 mg g −1 , far higher than HCP-RE (97 mg g −1 ) and most conventional porous polymers (typically <100 mg g −1 ). Systematic investigations revealed that the adsorption followed the Freundlich isotherm, driven by physical hydrogen bond and π···π interactions. Furthermore, HCP-B3 demonstrated wide antibiotic adaptability and maintained 92% adsorption capacity after five cycles. This work provided a rational design principle and fundamental insights into the structure–property-performance relationship for porous polymers as antibiotic absorbents.