Polymer Nanocomposites are now recognized as the most promising materials for various engineering applications. This new class of materials has shown enhanced magnetic, dielectic, thermal, optical and electrical properties. The study of polymer nanocomposites requires a multidisciplinary approach with impressive technological promise, involving novel synthesis techniques and an understanding of nanotechnology, physics, chemistry and surface science. This book incorporates the latest technical accomplishments in the area of polymer nanocomposites, focusing on their fabrication, characterization, properties and applications. The balance of this book leans more toward the dielectric and magnetic polymer nanocomposites. This book is intended for the research workers who are working in the field of ceramics, magnetics, polymer and polymer nanocomposites.