Fabrication of porous zeolite/chitosan monoliths and their applications for drug release and metal ions adsorption

Ordered porous zeolite/chitosan (Zel/Chi) monoliths were prepared by a unidirectional freeze-drying method, and their properties and structures were characterized by various instrumental methods. The metal ion adsorption and the drug release performance of the porous Zel/Chi monoliths were also studied. The release rate of cefalexin from drug-loaded Zel/Chi monoliths depended on the composition and porous structure of the monoliths. The metal ion adsorption capacity of the Zel/Chi monoliths was related to the concentration of the metal ions, the adsorption time and the Zel/Chi ratio. An experimentally maximum adsorption of 89 mg/g was achieved for Cu2+ ions. The Zel/Chi monoliths with adsorbed Cu2+ ions effectively catalyzed the reduction of 4-nitrophenol to 4-aminophenol and had good recyclability. They were easily recovered by simply removing them from the reaction system and rinsing them with water.