Various polymers such as nylon, polypropylene, polystyrene, ethylene vinyl acetate, epoxy resins, polyurethanes, polyimides, and polyethylene terephthalate can be reinforced by adding nanofillers with dimensions <100 nm. Fillers can be in the form of particles (minerals), sheets (exfoliated clay stacks), or fibers (carbon nanotubes or electrospun fibers). Polypropylene and clay are most widely used components for making nanocomposites. For proper dispersion of clay with polypropylene, maleic anhydride polypropylene is commonly used. The composites thus prepared have applications in food packaging, structural, chemical, electrical/electronic, and medical fields.