Optically transparent polymer composites: A study on the influence of filler/dopant on electromagnetic interference shielding mechanism

Abstract

Composite materials made of polymers and carbon‐based ferromagnetic filler are attractive for electromagnetic interference shielding through a combination of reflection and microwave absorption. It is possible to enhance their shielding properties by controlling electrical conductivity, dielectric, and magnetic properties. In this work, the aforementioned properties are tailored to achieve optically transparent films with microwave absorbing properties. Nanocarbon materials, namely carbon nanotubes, graphene nanoribbons (GNR) and their ferromagnetic nanocomposites with Fe3O4 and cobalt in PVA‐PEDOT:PSS matrix were made and tested in X‐band. The highest shielding effectiveness for PVA films with nanocarbon filler was observed for 0.5 wt% GNR − Fe3O4 at 16.36 dB (9.7 GHz) with 79.8% transmittance.

Electromagnetic shielding behavior of epoxy multi‐hybrid composites comprises of E‐glass fiber, Ag nanoparticle, and Ni nanosheet: A novel approach

“…Figure 4(B) exhibits the constitute and dimensions of sample holder. [25][26][27][28] Tables 3, 4, 5, and 6 display the attenuation loss dB at frequency range (E, F, I, and J band) in Un-modified and surface-modified epoxy HMR designations at different thickness "2, 2.5, and 3 mm." The SE of HMR composites improved with frequency and via high Ag/Ni content.…”

Shorted Micro‐Waveguide Array for High Optical Transparency and Superior Electromagnetic Shielding in Ultra‐Wideband Frequency Spectrum

“…Despite being promising electromagnetic shielding materials, conductive polymers suffer from exponential light transmission decay as their thickness increases, and the overall performance is also limited (EMI SE of 14.72 dB and transmittance of 79.8% for GNR-Fe 3 O 4 /PEDOT:PSS/PVA composite film). [9,14] Due to the limitation of intrinsic conductivity, developing next-generation polymer-based EMI shielding materials relies on rational structural design and new preparation methods. [21] The emerging nanomaterials graphene, presents high transparency of 97.8%, while its shielding performance is low (only 2.27 dB in the X band) due to its high sheet resistance, [11,15,[22][23][24] and its combination with other shielding materials are proven practical.…”

“…The practice has proved that the requirements for electromagnetic shielding and optical transmittance can be met simultaneously through the rational structure design of various transparent conductive materials. [9][10][11][12][13] To date, considerable studies have attempted to develop transparent EMI shielding materials based on metals, [10] polymers, [9,14] nanomaterials, [15][16] and composites, [8,11,17] which can be categorized into continuous conductive thin films and apertured type conductive materials based on their conductive structures.…”

Multifunctional Green Electromagnetic Interference Shielding Material for the Sub-6-GHz Band

“…10−12 Thus, EMW absorbing materials with good impedance matching could eliminate the incident EMWs and simultaneously cause no secondary reflections, which are the most desirable EMI shielding materials. 13 However, there has not been a quantitative standard for the definition of absorption shielding materials until 2019, when Cao et al (absorptive) EM shielding materials. 14 "Green" represents less or no harm to not only the internal environment (which means these EMI shielding materials can protect our bodies or workspace from EM radiation) but also the external environment (which means these EMI shielding materials are friendly to other living bodies or the external environment).…”

“…In recent years, using EM shielding materials has been the most effective way to shield external EMI or prevent leakage of internal EM information, which can isolate EM waves (EMWs) and effectively control their radiation from one area to another. , EMI shielding materials can be divided into reflection and absorption types according to their shielding mechanism . The highly conductive materials such as metals are typical EMW reflecting materials, which do not eliminate incident EMWs but only redirect them in other directions, which could cause strong secondary pollution to the EM environment. − Thus, EMW absorbing materials with good impedance matching could eliminate the incident EMWs and simultaneously cause no secondary reflections, which are the most desirable EMI shielding materials . However, there has not been a quantitative standard for the definition of absorption shielding materials until 2019, when Cao et al proposed the green index ( g s ) as a criterion for low-reflection (absorptive) EM shielding materials .…”