ELECTROSPINNING OF SILICA NANOFIBERS: CHARACTERIZATION AND APPLICATION TO BIOSENSING A Thesis by PEI-HSIANG TSOU

Electrospinning of Silica Nanofibers: Characterization and Application to Biosensing. (August 2006) Pei-Hsiang Tsou, B.S., National Chiao Tung University, Taiwan Chair of Advisory Committee: Dr. Jun Kameoka 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 K for 12 h. Electrospun silica nanofibers were characterized