Magnetic Hypercrosslinked Polymers With Tailored Porosity and Hydrophilicity for Superior Aniline Removal From Water

Magnetic hypercrosslinked polymers (MHBs) featuring high surface areas and tunable magnetic responsiveness were synthesized through a streamlined two‐step strategy. Hypercrosslinked polymers (HBs) were first produced by Friedel‐Crafts alkylation of benzyl alcohol (BA) and formaldehyde dimethyl acetal (FDA) under FeCl 3 catalysis, in which catalyst dosage was optimized to regulate the pore architecture. Subsequent thermal treatment of HBs with Fe(acac) 3 under nitrogen enabled the in situ growth of Fe 3 O 4 nanoparticles, yielding magnetic composites with adjustable porosity and magnetization. Among the obtained materials, MHB‐1 possessed a high specific surface area of 616 m 2 /g and a saturation magnetization of 21.1 emu/g. Batch adsorption experiments demonstrated that aniline uptake by MHB‐1 followed a pseudo‐second‐order kinetic model and conformed to the Langmuir isotherm with a maximum capacity of 553.72 mg/g at 20°C. Thermodynamic results further indicated a spontaneous and exothermic adsorption process, while regeneration tests confirmed excellent recyclability with 92.8% capacity retention after five cycles. These findings highlight MHB‐1 as a cost‐efficient, magnetically separable, and structurally robust adsorbent with strong potential for practical aniline removal from contaminated water.