Enhanced fluorescence achieved by introducing benzoic acid as coligand onto Tb3+ grafted PAN nanofibers

Abstract Coordination effect between C N groups of polyacrylonitrile (PAN) and rare earth ions is adopted to graft Tb3+ ions onto the surface of electrospun PAN nanofibers. Benzoic acid (BA) is introduced as a coligand to improve the fluorescence properties of the products. The products are tested by scanning electron microscopy, Fourier transform infrared spectroscopy, UV–Vis absorption spectroscopy and fluorescence spectroscopy. The effects of concentrations of Tb3+ and BA, and reaction time on products’ properties are studied. The results show that Tb3+ ions could be successfully grafted onto PAN nanofibers, but the fluorescence intensity of the resulting PAN@Tb3+ nanofibers is very weak. By contrast, the fluorescence intensity of PAN@(Tb3+/BA) nanofibers is significantly stronger than that of PAN@Tb3+ nanofibers after BA is introduced as the coligand, and meanwhile, the concentration quenching effect of Tb3+ ions is effectively inhibited. In addition, PAN@(Tb3+/BA) nanofibers are superior in structure, which not only effectively utilize the precious rare earth resources, but also ensure high mechanical strength. The novel products are expected to be used in fields such as fluorescent nanoscale devices and fluorescent probe technique.