Tsou, Pei-Hsiang (2006-08). Electrospinning of silica nanofibers: characterization and application to biosensing. Master's Thesis. Thesis uri icon

abstract

  • Electrospinning is a technique to achieve nanometer scale fibers. Similar to the conventional spin methods of making fabric, the viscous polymer solution is ejected from a spinneret; stretched and solidified in the air, the solution forms the fibers. The different part of electrospinning among others is that the fibers are driven by the electrostatic force, which induces the repulsion inside the liquid and further reduces the diameter. The resultant product is a non-woven membrane, which is porous; and the pore size is around several nanometers to a micrometer wide. In this work, the relationship between the diameter of electrospun silica fibers, experimental parameters such as concentration and voltage, and between pore size of the fiber membrane and experimental time were studied. Materials used in the process are Polyvinylpyrrolidone (PVP), butanol and spin-on-glass coating solution, which act as polymer carrier, solvent, and silica-precursor, respectively. Polymer/silica precursor composite fibers were ejected from the needle of a plastic syringe when an electrical field, as high as several kV/cm, was applied. Then silica fibers were achieved by baking the composite ones at 773 oK for 12 h. Electrospun silica nanofibers were characterized as a function of polymer solution parameters. The calcined fibers were examined by using a field emission scanning electron microscope. The results showed that the fiber diameters decrease with decreasing proportion of polymer and silica precursor, and increase with a higher electric field. Pore sizes, defined as the grid areas enclosed by fibers on nearby layers, were also examined and showed no time-dependent tendency when the electrospin time was between 1-5 min. Fiber membranes were then used as the platform for protein detection. The results were compared with the control, which used glass slides as the platform. The results make it possible to make a more sensitive biosensing device.
  • Electrospinning is a technique to achieve nanometer scale fibers. Similar to the
    conventional spin methods of making fabric, the viscous polymer solution is ejected
    from a spinneret; stretched and solidified in the air, the solution forms the fibers. The
    different part of electrospinning among others is that the fibers are driven by the
    electrostatic force, which induces the repulsion inside the liquid and further reduces the
    diameter. The resultant product is a non-woven membrane, which is porous; and the pore
    size is around several nanometers to a micrometer wide.
    In this work, the relationship between the diameter of electrospun silica fibers,
    experimental parameters such as concentration and voltage, and between pore size of the
    fiber membrane and experimental time were studied. Materials used in the process are
    Polyvinylpyrrolidone (PVP), butanol and spin-on-glass coating solution, which act as
    polymer carrier, solvent, and silica-precursor, respectively. Polymer/silica precursor
    composite fibers were ejected from the needle of a plastic syringe when an electrical
    field, as high as several kV/cm, was applied. Then silica fibers were achieved by baking
    the composite ones at 773 oK for 12 h. Electrospun silica nanofibers were characterized as a function of polymer solution parameters. The calcined fibers were examined by
    using a field emission scanning electron microscope. The results showed that the fiber
    diameters decrease with decreasing proportion of polymer and silica precursor, and
    increase with a higher electric field. Pore sizes, defined as the grid areas enclosed by
    fibers on nearby layers, were also examined and showed no time-dependent tendency
    when the electrospin time was between 1-5 min. Fiber membranes were then used as the
    platform for protein detection. The results were compared with the control, which used
    glass slides as the platform. The results make it possible to make a more sensitive
    biosensing device.

publication date

  • August 2006