Efficient adsorption of dyes from aqueous solution by poly(vinyl alcohol‐co‐ethylene) nanofibre membranes modified with β‐cyclodextrin

Abstract

In this paper, highly absorbent poly(vinyl alcohol-co-ethylene) nanofibre membranes modified by b-cyclodextrin were prepared to adsorb dyestuff from water, and 1,2,3,4-butanetetra carboxylic acid was used as a crosslinking agent, which greatly enhanced the adsorption capacity of the modified membranes. Field emission scanning electron microscopy and Fourier Transform-infrared spectroscopy were used to characterise the surface morphology and chemical structures of the membranes. Methylene Blue (MB) was used as the main adsorbed dye. The effect of pH value and concentration of the MB solution were also investigated, and equilibrium adsorption reached 139.2 mg/g when the pH value was 10.0. The adsorption process fitted well with the Langmuir adsorption isotherm model and was in accord with the pseudo-secondorder kinetic model. Moreover, the modified membranes proved to have selective adsorption, especially for some cationic dyes other than MB, and had the potential to be recycled multiple times.