Electromagnetic interference efficiency

Electromagnetic interference (EMI) testing has become more prevalent for materials that either emit or are affected by EMI. Shielding efficiency (SE) of materials is deterrnined by measuring electric field strength between a transmitter and receiver with or without the presence of the material under test. Several researchers have suggested a correlation between volume resistivity and SE values (300,301). 

Certain ECP nanocomposites are used as electromagnetic shielding agents. The efficiency of electromagnetic interference shielding can be enhanced by using ECP/CNM nanocomposites [86,87]. 

Electrical Conductivity. This quality is important to bleed off static charge and to avoid electromagnetic interference (EMI) (Sec. 5.9). It can be produced by adding carbon black, graphite, and especially metallic fillers (Table 5.23). This requires particle-to-particle contact, so flakes are more efficient than simple powders, and fibers are most efficient of all (Table 5.24). 

Like poly(pyrrole)s, poly(aniline)s show excellent antistatic behavior and have a high shielding efficiency for electromagnetic interference and are useful as anticorrosive... 

Skin therapy with medicine Minimal impedance to air Efficiency in trapping aerosol particles Anti-biochemical gases Micro/nano electronic devices Electrostatic dissipation Electromagnetic interference shielding Hiotovoltaic devices—nano-solar cell LCD devices... 

Fugetsu B, Sano E, Sunada M, Sambongi Y, Shibuya T, Wang X, Hrraki T (2008) Electrical conductivity and electromagnetic interference shielding efficiency of carbon nanotube/cellulose composite paper. Carbon 46(9) 1256-1258... 

Huang Y, et al. The influence of single-waUed carbon nanotube structure on the electromagnetic interference shielding efficiency of its epoxy composites. Carbon 2007 45(8) 1614-21. 

Coatings are seldom used on noncosmetic parts, especially so with power-train and suspension systems. However, coatings are being increasingly considered to enhance performance characteristics, such as fuel and chemical resistance, and as an efficient electromagnetic interference (EMI) shield for electrical and electronic housings. 

Electronic devices can also generate electromagnetic and radio frequency interference waves that can interfere with other electronic devices. These waves must be modulated and leakage to the environment prevented. Plastics, silicones, acrylics, and polyesters (qv) that are filled with conductive fillers, such as silver, nickel, and copper, are used for this application (1). Although nickel-filled polymers are low cost and efficient, these are not preferred because of the carcinogenic nature of nickel powder. 

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