Polystyrene (PS) fibers were fabricated via one-step electrospinning process, using tetrahydrofuran (THF) and N, N-dimethylformamide (DMF) as mixed solvent. The properties and structure of fibers were characterized by XRD, FTIR, DSC, FESEM, BET, and tensile strength analyses. The effect of operating parameters on the fiber structure in the electrospinning process was evaluated using the Taguchi experimental design. The production of fibers with a uniform surface, dense nanopores, and bead-free morphology can be controlled by optimizing the electrospinning conditions. For this purpose, the effects of solvent composition, solution concentration, feeding rate, and applied voltage were studied. The performance of the fibers was evaluated through adsorption and selectivity tests. The adsorption capacity of the fibers was measured using three different oil sources: sunflower oil, motor oil, and crude oil. The selectivity performance of the fibers was assessed with dispersed and dissolved crude oil in water. The results revealed that the maximum oil adsorption capacities of PS fibers for sunflower oil, motor oil, and crude oil were 58.4, 68.5, and 61.1 g/g, respectively. Furthermore, the PS fibers demonstrated excellent oil–water selectivity in the treatment of oily water. Moreover, polyaniline (PANI) was incorporated as a conductive polymer to enhance the properties of electrospun fibers. The conductive fibers exhibited improved microstructural properties and performance compared to PS fibers. The motor oil adsorption capacity increased to 71.5 g/g with the conductive PS/PANI fibers. The results of this study demonstrate that the conductive and hydrophobic PS/PANI fibers, as selective adsorbents, possess a high capacity for the adsorption of various oils.
