Magnetic polymer nanocomposites: Fabrication, processing, property analysis, and applications

Polymers are considered excellent host matrices for composite materials. They have been extensively investigated for their potential broad applications because of their easy processability, low-cost manufacturing, good adhesion to substrates [1], and unique physicochemical properties. Polymer nanocomposites are polymer composites using nanostructured materials as the fillers. Depending on the type of filler materials, different properties can be achieved for the polymer nanocomposites. Unique physicochemical phenomena such as giant magnetoresistance (GMR) or tunneling magnetoresistance (TMR) can be created, in which the nonmagnetic conductive or insulating polymer serves as a spacer, while magnetic inorganic materials are used as the fillers [2,3]. This phenomenon is completely beyond the simple addition of the advantageous physicochemical properties of a single polymer matrix and the magnetic inorganic fillers. A typical application of magnetic polymer nanocomposites is the GMR/TMR sensor. Various combinations of polymers and magnetic nanomaterials have been explored for magnetic polymer nanocomposite fabrication, including magnetic nanoparticles and conductive polymers such as iron or polypyrrole (Ppy), magnetic nanoparticles and insulating polymers such as iron or vinyl ester and iron or Polyurethane (PU), to name a few.