Selective molecularly imprinted polymer nanofiber sorbent for the extraction of bisphenol A in a water sample

Novel molecularly imprinted polymer nanofibers (MIP-NFs) were prepared for the adsorption of bisphenol A (BPA) in a water sample using the sol-gel process and the electrospinning technique. The effects of a number of synthesis parameters on the adsorption efficiency were investigated. The successful removal of BPA from MIP-NFs was studied using UV-visible spectroscopy. The prepared MIP-NFs were characterized by Fourier transform infrared, field emission SEM, TEM and energy dispersive X-ray analysis. The results showed that the required molar ratio of 3-aminopropyltriethoxysilane (APTES) to BPA was 15:1, which indicates a good performance in the rebinding test. Likewise, the molar ratio of APTES:acid:water was 1:2:9. The nylon 6 polymer solution, with a concentration of 12 wt%, showed a maximum adsorption capacity for BPA due to a decrease in the nanofiber diameter and an increase in the accessible sites. Furthermore, the maximum adsorption capacity of BPA was achieved at pH 7. Concerning the binding of BPA on MIP-NFs, the experimental data matched well with the pseudo-second-order kinetics data and the Sips isotherm model. The saturated binding capacity for MIP-NFs was predicted to be 115.1 mg g(-1), which was more than twice as high as that for non-imprinted polymer nanofibers (46.82 mg g(-1)). The results obtained in this study confirmed that the prepared MIP-NFs showed considerable binding specificity for BPA in comparison with similar structural compounds such as phenol, naphthol and Naphthol AS, in aqueous solution. The binding capacity of MIP-NFs remained almost constant after five cycles of reuse. The real sample analysis indicated that MIP-NFs could be utilized as a useful sorbent material for the extraction of BPA from a water sample.