Engineered Hollow Polymer Microspheres Based on β-Cyclodextrin for High-Capacity and Rapid Cationic Dye Adsorption

The escalating release of organic dyes in industrial effluents threatens environmental and public health. This study synthesizes a β-cyclodextrin-maleic anhydride hollow crosslinked polymer (St-DVB-MA-β-CD) through radical copolymerization of styrene-maleic anhydride (PMS) particles with divinylbenzene (DVB). The adsorbent demonstrates exceptional performance for cationic dye removal, surpassing benchmark materials. Within 10 min, > 90% removal efficiency was achieved for malachite green (MG), crystal violet (CV), astrazon pink FG (FG), and methylene blue (MB), indicating rapid adsorption kinetics. Maximum capacities reached 3896 mg/g (MG), 4036 mg/g (CV), 3869 mg/g (FG), and 3170 mg/g (MB). Adsorption conformed to the pseudo-second-order kinetic model and Langmuir isotherm, confirming monolayer chemisorption. Crucially, > 90% MG removal efficiency was preserved after five regeneration cycles, demonstrating robust reusability for dye removal.