The potential of nanographite as a bed material in fluidized bed system has not yet explored. In this work, metal coated nanographite based nanoparticles have been synthesized using fluidized bed system and their possibility to improve functional properties has been evaluated in polymer nanocomposite form. The electrolytic cell has been designed and process parameters are optimized considering the quantity and quality of deposited metals on nanographite. The synthesized nanoparticles have been dispersed in thermoplastic polyurethane to produce nanocomposite films, coatings and fibers. The functional properties such as microwave reflection loss under different frequency ranges, electrical impedance, gas barrier property, weathering resistance, etc have been studied in the form of nanocomposite films and coatings. The preparation of nanocomposite fibers in twin screw compounder using these nanoparticles has also been discussed in view of their conducting and strain responsive properties. Therefore, this book should be useful for technologists, industry personnel, students and researchers working on development of high performance polymer nanocomposites and hybrid nanoparticles.