Preparation and Characterization of Nanometer-scale Polycarbonate Fibers: Bead Formation

ABSTRACTElectrospinning is a superior process compared to other conventional spinning methods for the production of fibers in the sub-micron to nanometer scales. Such fiber membranes have exceptionally large surface areas and small pore sizes. The process requires an electrostatic force, which induces charges on the liquid droplet of the polymer solution or melts and therefore overcomes the surface tension and viscoelasticity forces to create an electrically charged jet. When the jet dries or solidifies, an electrically charged fiber remains, which can be directed or accelerated by the electrical forces and then collected in non-woven fiber membrane or other useful shapes. The present research work demonstrates the electrospinning of polycarbonate solution with solvent mixtures THF (Tetrahydrofuran) and DMF (Di-methyl formamide) to produce nanometer scale polycarbonate fibers. The solvent mixture of THF and DMF was the major parameter for producing nano-polycarbonate fibers along with the formation of byproducts beads. The electrostatic voltage, viscosity and surface tension also showed significant effect on bead formation and bead density. The microstructures of the polycarbonate beads were quantitvely investigated by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM).