Immobilization of β-cyclodextrin onto the surface of electrospun fibers as rapid and highly efficient adsorbent with good recyclability

It is still a big challenge to obtain adsorbents with high adsorption rate and improved adsorption capacity. Herein, we report a novel electrospun fibers adsorbent modified with carboxylated-β-cyclodextrin (CB-β-CD) molecules for the rapid and efficient removal of phenolphthalein (PHP) from water. First, CB-β-CD is synthesized by esterification of β-CD with succinic anhydride. Subsequently, by means of polydopamine (PDA) coating rich in amine groups, CB-β-CD is covalently bonded onto the surface of poly(vinylidene fluoride)@polystyrene/PDA (PVDF@PS/PDA) fibers through the amide linkage to obtain PVDF@PS/PDA/CB-β-CD fibers adsorbent. XPS, WCA and thermal properties results suggest that large amounts of CB-β-CD molecules hang over the surface of PVDF@PS/PDA/CB-β-CD fibers and the cavities of CB-β-CD molecules are well preserved, thus providing more sites to form inclusion complexes with guest molecules. The adsorbent exhibits excellent adsorption properties for PHP, with a saturation adsorption capacity of 39.97 mg/g after 10 min, which is superior to other reported adsorbents containing β-CD. Moreover, PVDF@PS/PDA/CB-β-CD shows good recyclability and highly selective adsorption of PHP, which has potential applications in molecular recognition, organic molecules separation, and water purification. The developed method provides a new strategy for immobilizing more β-CD molecules onto the surface of composite materials to endow superior comprehensive performances.