Development of the electrospun nanofiber media for filtration application: Effect of Moisture

摘要

In recent years, many researchers have studied and developed the nanofibers which have a large specific surface area and a small pore size. The polymer nanofibers are being used or finding uses in filtration, biomedical applications including wound dressings as structural elements in artificial organs, and reinforced composites. Thus these special needs have stimulated recent studies and renewed interest in the process, quantitative technical and scientific information regarding process and product characterization are limited. Conventional spinning processes depend on pressure driven extrusion of a viscous polymer and produce fibers which are typically in the range from 10 to 500 μm diameters. The electrospinning can allow producing and encouraging the utilization of nanofibers. When an electric field is applied to the solution, the suspended drop gets distorted and starts stretching to form a Taylor cone. The distortion is caused by a balance of the repulsive forces induced on the drop due to the charge distribution and the surface tension of the liquid. When the voltage reaches a critical value, the electric force overcomes the surface tension of the deformed drop of the suspended polymer solution formed on the tip of the syringe, and a jet is produced. A jet travels through the air, the solvent evaporates leaving behind polymer fibers to be collected on an electrically grounded target. The surface morphology of e-spun fiber is affected by many variables that involve polymer concentration, applied voltage, spinning distance, air friction, gravity and ambient parameters. This study shows the effect of polymer concentration and relative humidity on the microstructures of the e-spun Polystyrene (PS) fiber.