Ultrafine polystyrene(PS) nanofibers were prepared via the simple electrospinning technique.Uniform and smooth PS nanofibers were obtained with adding the organic salt BTEAC into the PS solutions and adjusting the concentration of PS solutions.Without the addition of BTEAC,PS fibers with few beads could be achieved with a PS mass fraction of 20%,and the average diameter of the fibers was 280 nm.The addition of the organic salt BTEAC could lower the critical concentration for the fiber formation and reduce the amount of beads on the fibers.Unltrafine PS fibers without any beads were obtained with a PS mass fraction of 10% and an ionic salt mass fraction of 0.5%.The average diameter of the fiber was successfully reduced to 100 nm.The influence of the salt concentration on the morphology and diameter of the PS fibers was also investigated.The viscosity and surface tension changes were measured with changing the concentration of BTEAC.The results show that the changes were so small that these factors could be ignored.It was suggested that variations of the fiber diameter should be mainly resulted from the changes of conductivity and conformation of the polymer chain as the concentration of BTEAC is varied.
Porous TiO2/ZnO composite nanofibers have been successfully prepared by electrospinning technique for the first time.It was generated by calcining TiO2/ZnCl2/PVP[PVP:polyvinyl pyrrolidone)]nanofibers,which were electrospun from a mixture solution of TiO2,ZnCl2 and PVP.Transmission electron microscopy(TEM) and X-ray diffraction(XRD) analyses were used to identify the morphology of the TiO2/ZnO nanofibers and a formation of inorganic TiO2/ZnO fibers.The porous structure of the TiO2/ZnO fibers was characterized by N2 adsoption/desorption isotherm.Surface photovoltage spectroscopy(SPS) and photocatalytic activity measurements revealed advance properties of the porous TiO2/ZnO composite nanofibers and the results were compared with pure TiO2 nanofibers,pure ZnO nanofibers and TiO2/ZnO nanoparticles.