preparation of diethylenetriamine modified polyacrylonitrile nanofibers for cadmium ion adsorption

Abstract

In this study, the electrospinning method was used to manufacture polyacrylonitrile (PAN) nanofibers. The procedure involved spinning a solution of 10%wt PAN in dimethyl formamide (DMF) in an electric field of 21 kV and with a tip to collector distance of 16 cm. The nanofibers thus obtained had an average diameter of 100 nm. Then, scanning electron microscopy (SEM) images were used to investigate the morphology of the nanofibers. In the next step, the nanofiner surface was modified with diethylenetriamine and FTIR was employed to ensure the presence of amines on the nanofiber surface. The functionalized nanofibers were then used for the first time to adsorb ions of cadmium (a heavy metal with industrial applications) and its adsorption capacity was evaluated. The chemical charactristics of the nanofibers and the effects of such parameters as pH, temprature, and contact time on adsorption efficiency were investigated. The results showed that maximum adsorption efficiency was achieved within the first 10 minutes of the process at a pH in the range of 5‒7 when about 80% of the cadmium ions were adsorbed.. Moreover, only slight changes were observed with longer contact times or with increasing temperature. Finally, the adsorption data fitted well with the Langmuir isotherm