Applications electromagnetic interference shielding

D. M. Bigg, D. E. Stutz, Plastic Composites for Electromagnetic Interference Shielding Applications. Polym Compos 1983,4,40-46. 

J. Azadmanjiri, P. Hojati-Talemi, G. P. Simon, K. Suzuki, C. Selomulya, Synthesis and Electromagnetic Interference Shielding Properties of Iron Oxide/Polypyrrole Nanocomposites. Polym EngSci 2011, 51, 247-253. Semiconducting Polymer Composites Principles, Morphologies, Properties and Applications X. Yang, Ed. Wiley-VCH Weinheim, 2012. 

Bigg, D.M. and Stulz, D.E. (1983) Plastic composites for electromagnetic interference shielding applications. 

Conductive polymer composites (CPC) exhibit a series of unique features, such as comparatively low room temperature resistivity, percolation phenomenon, resistivity sensitivity to temperature, pressure and gas, and nonlinear voltage-current relationship [1-5]. They found wide industrial applications in the fields of antistatic materials, self-regulating heaters, over-temperature protection devices, and electromagnetic interference shielding. Therefore, fundamental and applied studies of CPC are currently of great interest. 

The polymer/CNT nanocomposites can be used for some other applications, for which conductivity requirements are not as severe. Among these applications may be mentioned electromagnetic interference shielding, electrostatic dissipation, touch panels, display panels, which need to be transparent in addition to presence certain conductivity. The nanocomposites may be also used to dissipate heat or as flame retardant, and in the biological field, as part of sensors (Grady 2011). 

Initially, conductive fibers were mainly used in technical areas such as clean room garments, military apparel, medical application, and electronics manufacturing (Resistat, 2015). They can have a variety of functions, like antistatic apphcations (Sophitex, 2015), ElectroMagnetic Interference shielding (LessEMF, 2015), electronic apphcations, infrared absorption or protective clothing in explosive areas (Mcfarland etal., 1999). 

Unlike many doped conductive polymers, the electrical conductivity of these polymers is environmentally stable. Exposure to air for two years and water for 80 days produces little change in the conductivity. Potential applications proposed for this type of polymer include use as a matrix for advanced composites, and in electromagnetic interference shielding and electrostatic dissipation materials. 

Finally, SWCNT concentrations higher than 0.3 and 3wt%, respectively are sufficient for applications in electrostatic painting and electromagnetic interference shielding, respectively (Figure 10.8). Other applications of electrically conductive CNT-polymer composites are in printable circuit wiring and as transparent conductive coatings. 

The properties of developed electrospun nanofibers are key issues for then-applications in industry. Here, the structure and morphology of the nanofibers were characterized by field emission scanning electron microscopy, transmission electron microscopy. X-ray powder diffraction, and their electromagnetic interference shielding effectiveness and magnetic property were also evaluated for electromagnetic shielding applications. 

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