Electrospun cyclodextrin-functionalized mesoporous polyvinyl alcohol/SiO2 nanofiber membranes as a highly efficient adsorbent for indigo carmine dye

A mesoporous polyvinyl alcohol (PVA)/SiO2 composite nanofiber membrane functionalized with cyclodextrin groups was prepared by sol–gel/electrospinning process. The spinnable sol was synthesized by one-step co-condensation of tetraethyl orthosilicate (TEOS) and silylated monochlorotriazinyl-β-Cyclodextrin (APTES-β-CD), with cetyltrimethyl ammonium bromide (CTAB) as template. After the addition of PVA, nanofiber membranes were prepared by electrospinning. The membranes were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) images, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption–desorption measurement and an Elementar Vario EL analyzer. The composites were used as highly efficient adsorbents for indigo carmine dye due to the presence of cyclodextrin groups and were conveniently separated from the waste water. Furthermore, the composite could be regenerated through acidification.