Advanced Materials for Electromagnetic Shielding
by Maciej Jaroszewski, Sabu Thomas, Ajay V. Rane
12Nanocomposites Based EMI Shielding Materials
Hossein Yahyaei and Mohsen Mohseni
Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran, Iran
12.1 Nanomaterials and Nanocomposite Materials
When the size of materials are reduced new effects will appear that give rise to special properties. For example, at nano‐scale the gravitational force is negligible and electromagnetic forces are dominant and determine the behavior of materials. In materials that are nano scale size, the wavelike behavior becomes more pronounced. One of the consequences of this behavior is the tunneling phenomenon. Quantum confinement is also a consequence of the particle wave quality. The most famous and most important consequence of the small particle size is the huge surface area. The surface forms a sharp interface between a particle and its surrounding atmosphere. Nanoparticles have great number of surface atoms relative to those in the volume. Simple calculations show that the ratio of surface to volume is inversely proportional to the diameter of the particle.
Materials that are opaque in micro or higher dimensions become transparent at nano dimension. In addition, the high surface area at nano dimension increases the surface energy and friction, which causes an increase in particle–particle interactions. Nanofillers based on their dimension that are not at nano scale are classified in three groups. One is fibrous or tube‐like filler with a diameter less ...