Preparation Of Ion-exchange Nanofiber And Its Application To Cu(Ⅱ) Adsorption

In this paper, the electrospun PAN nanofiber added polyaniline doping with dodecylbenzene sulfonic acid to decrease the fiber diameter was prepared, so the nanofiber membranes have high surface area and high porosity. As the DBSA doping concentration increased, the PAN solution conductivity was increasing, the average diameter of fibers was gradually decreasing. When the concentration of dodecylbenzene sulfonic acid increased to 1.1 mol/L, the solution conductivity did not change, so choosing the 1.1mol/L as the highest dope concentration. When the dodecylbenzene sulfonic acid's concentration was 1.1mol/L, the minimum average diameter was 116nm.The nanofibers with DBSA doping concentration of 1.1mol / L were prepared by alkaline hydrolysis to prepare the ion-exchange nanofiber. With the modification time increased, the fiber surface wad introduced in Cu (â…¡) ions adsorption group of-COOH and-CONH2, but at the same time the fibers was cross-linked, so the ion-exchange nanofiber membranes'tensile strength was increased, the elongation at break decreased. Form the Cu (â…¡) ion adsorption experiment, it is found that the adsorption amount increases with pH and the temperature, their Cu (â…¡) ion adsorption kinetics fit with the pseudo-second-order equation. The Langmuir adsorption model can be applied in this affinity system, through the Langmuir adsorption isotherm model, it can calculate the largest Cu (â…¡) ion adsorption capacity, which was 95.15mg/g. After 5 times desorption and reuse, its absorption amount was still more than half of the first time. And compared with the ion-exchange micronfiber prepared at the same conditions, it was found that the adsorption amount of ion-exchange nanofiber higher than the ion-exchange micronfiber, especially when the modification time was 30min, the adsorption capacity increased 143%.In order to preparation the different ion-exchange nanofiber to adsorption Cu (â…¡) ion, we also use the nanofibers with DBSA doping concentration of 1.1mol/L. In this time the chelating nanofibers was prepared by aminolysis with aminoethyl alcohol. Experiments results showed the morphology of the chelation nanofiber is very good within the modified time 1-3h. With the modification time increased, the nano-fiber cross-linked, so resulted in the increasing of tensile strength, decreasing of elongation at break. Chelating nanofiber for Cu (â…¡) ion adsorption results showed that the adsorption capacity increases with pH, increases with the temperature rising, the adsorption kinetics are consistent with peseudo-second-order, the adsorption isotherm followes with the Langmuir model. It can calculate the largest Cu (â…¡) ion adsorb capacity, it was 124.53mg/g. After 5 times'desorption and reuse, its absorption amount was still more than half of the first time. And compared with the chelating micronfiber prepared at the same conditions, it was found that the adsorption amount of chelating nanofiber higher than the chelating micronfiber, especially when the aminolysis time of 1h, the adsorption capacity increased 173%.