Author(s):
Ravi Kant and M. Fahim
Abstract:
Modern era devices and appliances require shielding from electromagnetic interference
to ensure stable and efficient functioning. This is all the more pertinent in view of the safety and
protection of electronic gadgets used in defence security equipment. It has been observed that the
most prominent radiations of EMI fall in the range of microwave (GHz) and radio waves (MHz).
Those materials which protect equipment from electromagnetic interference are called EMI
shields, since they shield the equipment by either reflecting, absorbing or transmitting the
electromagnetic radiation. However, not all materials can be used as EMI shields. The basic
material requirement to be used as EMI shields include good magnetic permeability and dielectric
properties as well as strong mechanical properties. Currently EMI shields made up of metals or
silicones are used in the form of solid enclosures, cables, gaskets, O-rings, films, coatings, fabrics,
tapes etc. With time and research new advanced lightweight materials have been developed which
have shown potential for use as EMI shields. These include carbonaceous and ferrite nanofillers
based polymer nanocomposites. These materials are unique because they provide shielding for a
wide range of microwave frequency 2-18 GHz by a judicious choice of conductive, dielectric and
magnetic nanofillers. The present review article provides an overview of the research work carried
out on toughened epoxy (epoxy modified with other polymers) filled with multifunctional
nanoparticles and their characterization for EMI shielding efficiency. Various factors and features
have been critically analysed in this article. The entire focus of the article is aimed at Toughened
epoxy as a base matrix which can support EMI shielding in the complete frequency range of 2-18
GHz and overcome inherent disadvantages of non-toughened epoxy.
Pages: 244-256
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