Recent Advances in Polymer Nanocomposites for Electromagnetic Interference Shielding: A Review

Abstract

The mushrooming utilization of electronic devices in the current era produces electromagnetic interference (EMI) capable of disabling commercial and military electronic appliances on a level like never before. Due to this, the development of advanced materials for effectively shielding electromagnetic radiation has now become a pressing priority for the scientific world. This paper reviews the current research status of polymer nanocomposite-based EMI shielding materials, with a special focus on those with hybrid fillers and MXenes. A discussion on the theory of EMI shielding followed by a brief account of the most popular synthesis methods of EMI shielding polymer nanocomposites is included in this review. Emphasis is given to unravelling the connection between microstructures of the composites, their physical properties, filler type, and EMI shielding efficiency (EMI SE). Along with EMI shielding efficiency and conductivity, mechanical properties reported for EMI shielding polymer nanocomposites are also reviewed. An elaborate discussion on the gap areas in various fields where EMI shielding materials have potential applications is reported, and future directions of research are proposed to overcome the existing technological obstacles.

Figure 1

Schematic illustration of the electromagnetic shielding mechanism.

Figure 2

Schematic representation of the vector network analyzer.

Figure 3

(a) Schematic image of the allocation of silver nanocompositions in composite foams for PIF-P, PIF-W, and PIF-WS. Inset: indicates the 3D model of the allocation of silver nanofillers in composite foams. Specific EMI SE of composite foams for PIF-P, PIF-W, and PIF-WS calculated in frequency ranges (b) 30 MHz–1.5 GHz and (c) X-band. Inset (b) displays their specific EMI SE at 200, 600, and 1000 MHz. Inset (c) displays the specific EMI SE of composite foams at 9.6 GHz. Reprinted with permission from (87). Copyright 2015, Royal Society of Chemistry.

Figure 4

Resemblance of SE_T, SE_A, and SE_R at the frequency of 10 GHz for the (a) solid (s-PC and e-PC) and (b) s-PCF (segregated PSU/CNT composite foam) and e-PCF (conventional extruding PSU/CNT composite foam) with various CNT loadings. Resemblance of T, R, and A at the frequency of 10 GHz for the (c) solid and (d) s-PCF and e-PCF composites with various CNTs loadings. Reproduced with permission from ref (107). Copyright 2020, Royal Society of Chemistry.

Figure 5

(a) Scheme of the procedure for preparing P-GN and AEMA-GN. (b) The AEMA-GN attached to the sulfonated functional groups of WPU through electrostatic attraction for better compatibility. Reprinted with permission from ref (116). Copyright 2015 American Chemical Society.

Figure 6

Illustration of the shielding mechanism and EMI SE of the rGO@Fe₃O₄/T-ZnO/Ag/WPU composite film and SEM image of the fracture surface of the double-layer structure. Reprinted with permission from ref (136). Copyright 2018 American Chemical Society.

Figure 7

Schematic sketch of the EM waves transfers throughout the 3D GNPs/rGO/EP nanocomposites. Reproduced with permission from ref (137). Copyright 2019, Royal Society of Chemistry.

Figure 8

EMI SE_T of the 3D GNP/rGO/EP and rGO/EP nanocomposites in the X-band. (B) Evaluation of microwave reflection (SE_R) and absorption (SE_A) at the X-band. (C) Evaluation of EMI SE_T of 3D GNP/rGO/EP and GNP/EP nanocomposites fabricated with two various methods in the experimental part. (D) The absorption, reflection, and transmission against the rGO/EP and 3D GNPs/rGO/EP nanocomposites at 12.4 GHz. Reprinted with permission from ref (137). Copyright 2019, Royal Society of Chemistry.

Figure 9

Schematic illustration of the mechanism of electromagnetic wave propagation through filler-reinforced polymer composites containing (a) orderly distributed microwires/graphene fibers MMMGGG and (b) randomly distributed microwires/graphene fibers M +G. Reproduced with permission from ref (138). Copyright 2020, Elsevier.

Figure 10

Schematic illustration of the shielding mechanism for the CEF-NF/Ag/WPU films transferring across the material. Reproduced with permission from ref (139). Copyright 2020, Elsevier.

Figure 11

Schematic illustration of electromagnetic microwave distribution in the PP/CNT/CB nanocomposite foams. Reproduced with permission from ref (140). Copyright 2020, Elsevier.

Figure 12

Electromagnetic shielding mechanism of the FeCLPU biocomposite. Reproduced with permission from ref (142). Copyright 2021, Elsevier.

Figure 13

Schematic illustration of the shielding mechanism of the composites with high MWCNT or GNP loadings. Reproduced with permission from ref (143). Copyright 2021, Elsevier.

Figure 14

Schematic explanation for fabrication of MXene/AgNW composite films. Reproduced with permission from ref (169). Copyright 2020, Royal Society of Chemistry.

Figure 15

(a) Comparison of electrical conductivities and thickness of pure MXene film (TC) and MXene/AgNW hybrid films (TN 0.5A, TN 0.25A···) with diverse nanocellulose (NC) to MXene weight ratios. (b) EMI SE of MXen/AgNW hybrid films in the X-band. (c) Total EMI SE (SE_T) and its reflection (SE_R) and absorption (SE_A) of MXene/AgNW and pure MXene film composite films at a frequency of 8.2 GHz. (d) Comparison of SE_T, SE_A, and SE_R of TC film and TN0.167A composite film in the X-band. Reproduced with permission from ref (169). Copyright 2020, Royal Society of Chemistry.

Figure 16

Schematic illustration of EMI shielding mechanisms of cross-linked PEDOT:PSS-Ti₃C₂T_x MXene. Reproduced from reference (170) with permission from the Royal Society of Chemistry.

Figure 17

2D MXenes carried out as shields against EMI. (a) The class of various MXene structures for efficient EMI shielding and (b) the number of periodicals concentrated on MXenes for EMI shielding. Reproduced with permission from ref (172). Copyright 2020, Wiley.

Figure 18

Bar diagram representing the number of publications with three different keyword combinations, i.e., “EMI shielding” together with “Polymer”, “EMI shielding” with “polymer” and “filler”, and “Polymer nanocomposites” with “EMI shielding” in the last 6 years (until February 2022) from the Scopus database.