Polymeric composites reinforced with inorganic fillers have attracted much interest due to their reduced weight, high homogeneity, cost-effective processability and tunable physical such as mechanical, magnetic, optical, electric and electronic properties. The applications have extended into the marine (Naval submarine) and airplane (Boeing 787) industries. Furthermore, nanoparticles (NPs) within the polymeric matrix render the nanocomposite potential electronic device applications such as fuel cells, photovoltaic (solar) cells, batteries and magnetic data storage. On the other side, the functional groups of the polymer surrounding the nanoparticles enable these polymer nanocomposites suitable for variable applications such as site-specific molecule targeting application in the biomedical areas.

Particle dispersion together with the interaction between fillers and polymer matrix are major challenges in the polymer composite manufacturing. The particle agglomerates and voids resulting from the poor bondage will serve as defects, which will definitely give deleterious physical properties such as lower tensile strength for structural material application and poorer electron transport path for integrated polymer composite electric/electronic device applications.

We have demonstrated strengthened polymer nanocomposite fabrication by surface engineering the particles.[1] However, functionalization is an extra cost for production with high particle loading. Consequently, several simple and low-cost methods (surface-initiated-polymerization and monomer stabilization method)[2-3] were developed for high-quality nanocomposite fabrication.

Polymer nanocomposites were developed into a granular giant magnetoresistance (GMR) sensor [4-5] with the highest signal among these systems. Compared with metallic matrix GMR, the polymer matrix could be facile fabrication, low-cost usage without any packaging requirement and suitable for harsh environmental applications, ready to be used in specific biomedical areas.

In this presentation, the composite fabrication methodologies and the application in the granular GMR sensor will be discussed.

Ref:

[1]Z. Guo; T. Pereira; O. Choi; Y. Wang; H. T. Hahn; Journal of Materials Chemistry, 16, 2800-2808 (2006)

[2]Z. Guo; S. Park; S. Wei; T. Pereira; M. Moldovan; A. B. Karki; D. P. Young; H. T. Hahn, Nanotechnology, 18, 335704 (2007).

[3]"Facile Monomer Stabilization Approach to Fabricate Iron/Vinyl Ester Resin Nanocomposites," Composites Science and Technology, accepted.

[4] Z. Guo; S. Park; H. T. Hahn; S. Wei; M. Moldovan, A. B. Karki; D. P. Young, Applied Physics Letter, 90, 053111 (2007).

[5]"Magnetic and Magnetoresistance Behaviors of Particulate Iron/Vinyl Ester Resin Nanocomposites," Z. Guo; H. T. Hahn;H. Lin; A. B. Karki; D. P. Young, Journal of Applied Physics, accepted.