Magnetic porous superabsorbent: synthesis, characterization, and efficient adsorption of methylene blue

Access to clean, safe water is vital for environmental health and human well-being. We synthesized a magnetic porous superabsorbent via aqueous solution polymerization using acrylic acid, acrylamide, sodium alginate, Fe₃O₄, and sodium dodecyl sulfate. Its properties were characterized via infrared spectroscopy, scanning electron microscopy, and laser confocal microscopy. The superabsorbent exhibited superparamagnetic behavior with a maximum saturation magnetization of 5.79 emu/g and exceptional swelling, absorbing 258.6 g/g in distilled water. Its continuous porous structure facilitated rapid water absorption. Regarding adsorption, it effectively removed methylene blue, with a capacity of 459.0 mg/g in a 300 mg/L solution. After six adsorption–desorption cycles, it retained 80% of its capacity. These findings suggest a promising strategy for developing high-performance adsorbents to remove organic dyes from aquatic environments.