β-Cyclodextrin functionalized coaxially electrospun poly(vinylidene fluoride) @ polystyrene membranes with higher mechanical performance for efficient removal of phenolphthalein

摘要

Core-shell structured fibers of poly (vinylidene fluoride) and polystyrene (PVDF@PS) were coaxially electrospun from two kinds of polymer solutions. The presence of PVDF as a core component greatly enhanced the mechanical properties of PVDF@PS fiber membranes due to the crystallization of PVDF, and the tensile strength as well as the elongation at break were 12.3 and 28.2 times higher than that of individual PS respectively. Then beta-cyclodextrin (beta-CD) molecules were attached onto the surface of PVDF@PS fibers using polydopamine (PDA) as an intermediate layer, achieving the functionalization of fiber membranes (PVDF@PS/PDA/beta-CD). In comparison with other adsorbents containing beta-CD, the as-prepared membranes exhibited an efficient adsorption capability of 19.24 mg/g for phenolphthalein (php) by the formation of inclusion complexes with beta-CD and the interaction of hydrogen bond with PDA to some extent. Moreover, the membranes could be regenerated easily and retained about 86% of adsorption efficiency after five cycles. These results demonstrated the promise of PVDF@PS/PDA/beta-CD membranes for removal of organic compound from aqueous media.