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 FeCl₃ 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 Fe₃O₄ nanoparticles, yielding magnetic composites with adjustable porosity and magnetization. Among the obtained materials, MHB-1 possessed a high specific surface area of 616 m²/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.