Influence of Mixed Solvent in the Morphology and Hydrophobicity of Electrospun Polystyrene Porous Fibers

Electrospun polystyrene (PS) fibers are produced using a mixed solvent of chloroform and n,n‐dimethylformamide (DMF) to investigate the influence of the solvent ratio on the fiber surface morphology and contact angle of the obtained mats. Electrospinning is a simple processing technique for producing fibers with diameters in the range of nanometers to a few micrometers. When using the different solvent ratios for this process, porous PS membranes are created due to nonsolvent and thermally induced phase separation (N‐TIPS). The morphology of the fibers is analyzed through scanning electron microscopy (SEM), which showed that fibers have diameters between 200 nm and 6 µm. SEM also revealed that the pores present on the surface of the fibers vary from densely compacted and well‐formed nanopores with diameters in the range of 20–50 nm to larger pores with sizes of ≈100–200 nm. The pore size varied with different solvent ratios. The surface area is analyzed using the Brunauer–Emmett–Teller (BET) method and found that the polymeric fibers have a high surface area (≈35 m2 g−1). The fibers with such morphology are highly hydrophobic, with a contact angle higher than 143°. These materials are excellent candidates for applications in textiles, filtration, and biomedical fields. The study found that solvent ratios and voltage affect fiber morphology and hydrophobicity in electrospun PS fibers. A 70:30 ratio produced porous fibers, while 30:70 yielded beaded ones. Higher voltages increased the number of beads and pore size. All samples have contact angles above 130°, showing that beads or porosity enhance hydrophobicity.