(403d) Magnetic Polyacrylonitrile Nanocomposite Fibers: Fabrication, Property Analysis and Sensor Applications

Polymer nanocomposites have attracted much interest due to their light weight, flexibility, cost-effective processability, high tensile strength, thermal stability, chemical resistance and unique properties (electrical, optical and chemical). Combining the advantages of both the polymer matrix and inorganic components, polymer nanocomposites have wide potential applications in areas such as microwave absorption, sensors, smart materials, batteries, and solar cells. One dimensional (1-D) nanocomposite fibers with higher aspect ratio and larger specific surface area are superior to the thin film or bulk counterparts. Copmpared to the drawing, template synthesis, phase separation, and self-assembly for fiber fabrication, electrospinning is the low-cost way to produce nanofibers with high speed. The electrospun nanofibers have several remarkable advantages including tunable diameter (50 nm-10 µm), long in length, large specific surface area (surface area to volume ratio), diverse in composition, unique physicochemical properties along with the design flexibility for chemical/physical surface functionalization. Iron-group metallic nanoparticles are of interest due to their unique physicochemical properties such as enhanced magnetic moment and coercivity arising from their small size and high specific surface area, which differ from the corresponding bulk and atomic counterparts.

In this study, uniform polyacrylonitrile (PAN) nanocomposite fibers with different magnetic nanoparticle loadings have been fabricated via high-voltage electrospinning process. The surface morphology, thermal stability, particle structural characterization, crystal (phase) structure of the nanocomposite fibers are characterized by various techniques including scanning electron microscopy (SEM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), attenuated total reflection Fourier Transform Infrared (FTIR) spectroscopy, and X-ray diffraction (XRD), respectively. The magnetic properties and magnetoresistance were carried out in a physical properties measurement system (PPMS) by Quantum Design and by four probe measurement, respectively. The application of the nanocomposites in GMR sensor will also be discussed.

Referecne:

Electrospun Polyacrylonitrile Nanocomposite Fibers Reinforced with Fe3O4 Nanoparticles: Fabrication and Property Analysis, D. Zhang; D. Rutman; D. Cocke; Z. Guo*; A. B. Karki; D. P. Young; A. Wang, Polymer, in press (2009)