3.1.2. Interpretation of Graphene@Iron@Polymer Based Composites Articles
Different fillers are used with polymer composites to enhance the underlying matrix material. Carbonaceous fillers such as carbon black, carbon nanotubes, carbon nanofibers, graphene and graphene nanoplates have shown benefits in improving the mechanical properties of polymer composites
[83][84]. Adding graphene to a polymer has been shown to result in effective EMI shielding properties as it has the capability to create conductive networks within the polymer matrix
[85][86][87]. In addition to improved filler materials, polyaniline (PANI) comes as the matrix material
[88]. Shakir et al.
[89] evaluated EMI shielding properties by utilizing polymer blends of polyvinyl chloride (PVC) and PANI with graphene nanoplatelets (GNP) insertion. An enhanced electrical conductivity was noticed both for PVC/PANI and PVC/PANI/GNP composites. The EMI shielding effectiveness of 51 dB was achieved in the 18–20 GHz range. Khasim
[90] used PANI and graphene nanoplatelet composite for microwave shielding applications. The composite was prepared keeping 1.5 mm thickness by using in-situ polymerization. It was revealed that with 10 wt.% loading of graphene nanoplatelet, high shielding effectiveness (up to 95%) was achieved in X-band frequency. Also, it was revealed that the high absorption occurs due to the dominant absorption mechanism. Having improved conductivity, better thermal stability, and excellent EMI shielding properties, the composite is recommended for its application in X-band microwave frequencies. Jia et al.
[91] formed TiO
2/PANI/Graphene oxide (GO) composite via in-situ growth. The reflection loss was examined within the range of 2–18 GHz where the maximum came as −51.74 dB at 9.67 GHz frequency. Liu et al.
[92] used in-situ growth and hydrothermal method to synthesize magnetic graphene with PANI and porous TiO
2 and tested its EMI shielding efficiency within the range of 2–18 GHz. Keeping the sample thickness as 1.5 mm, a reflection loss of −45.4 dB was achieved.
Wang et al.
[93] synthesized graphene@Fe
3O
4@PANI decorated with WO
3 particles by using a hydrothermal method and chemical oxidation polymerization. The spherical nanoparticles of Fe
3O
4 and WO
3 having a diameter of 300–500 nm and 50–150 nm were spread in between graphene@PANI layers. The results showed that graphene@Fe
3O
4@PANI@WO
3 gives better electromagnetic wave absorption as compared to graphene@Fe
3O
4 and graphene@Fe
3O
4@PANI, where maximum achieved absorption was −46.7 dB with a coating thickness of 4 mm. Whereas, the maximum absorbing bandwidth was ≤10 dB of 1.8 GHz (from 12.4 to 14.2 GHz) with a thickness of 1.5 mm. Wang et al.
[94] fabricated a graphene@Fe
3O
4@SiO
2@polyaniline composite which gives better reflection loss of −40 dB at 12.5 GHz with 2.5 mm thickness and absorption bandwidth below −10 dB of 5.8 GHz (from 10.5 to 16.5 GHz) when compared with graphene@Fe
3O
4. Zhao et al.
[95] used the Hummers method to synthesized polyaniline (PANI), graphene oxide (GO) and Fe
3O
4 as EMI shielding composite. With a sample thickness of 3.91 mm, a reflection loss of −53.5 dB was observed within the range of the 2–18 GHz frequency.
In another study, PANI composite comprised of graphene and silver nanoparticles were used as EMI shielding material where the shielding effectiveness of 29.33 dB in 0.4–1.6 GHz frequency range was achieved at 5 wt.% loading
[96]. Ma et al.
[97] formed Fe
3O
4/PANI rod/RGO composites to deal with the EMI which was tested under the range of 2–18 GHz where a reflection loss of −33.3 GHz was achieved. In the study, the material thickness was increased from 1 mm to 4 mm where the maximum reflection loss was achieved at 3.5 mm thickness. It proves that by increasing the sample thickness the shielding effectiveness can be increased but up to a certain level. Wang et al.
[98] synthesized graphene@NiO@PANI@Ag using hydrothermal and in-situ growth method. The composite material was tested within the range of 2–18 GHz where a reflection loss was achieved as −37.5 dB with 3.5 mm sample thickness. Zhou et al.
[99] formed graphene-doped polyaniline (G-PANI) as shielding composite via in-situ growth. The shielding effectiveness of 32.5 dB was achieved within the range of 2–18 GHz with 1.5 mm thickness. Singh et al.
[100] formed a new material ℽ-Fe
2O
3 and decorated it with RGO and PANI to observe the shielding efficiency of the composite. The composite was formed via chemical oxidation polymerization and in-situ growth and tested within the X-band frequency range. While keeping the sample thickness as 2.5 mm, total shielding effectiveness of 51 dB was achieved. Wang et al.
[101] explored Ti
3C
2T
x MXene shielding properties by making its composite with Fe
3O
4 and PANI polymer. The co-precipitation method was used to prepare the composite and was tested within the X-band frequency range. Shielding effectiveness of 58.8 dB was achieved with 12.1 µm sample thickness. Preeti et al.
[102] used the citrate precursor method to synthesize RGO, barium ferrite (BF) and PANI to form a shielding composite where shielding effectiveness of 31.1 dB was achieved in the X-band frequency range. Dar et al.
[103] synthesized PANI/Li
0.5Fe
0.5−xGd
xO
4 via in-situ growth where the composite was tested within the X-band frequency range. Keeping the sample thickness as 0.2 mm, shielding effectiveness of 42 dB was achieved.
Yan et al.
[80] evaluated ultra-efficient electromagnetic interference shielding by using reduced graphene oxide and polystyrene. The results showed that with 3.47 vol% of RGO-based polymer composite, 45.1 dB shielding effectiveness was achieved. Shahzad et al.
[104] formed two different composites via a hot compressed method. One was segregated RGO with polystyrene (PS) and the other was conventional RGO/PS. The testing was made from 0–20 GHz where the shielding effectiveness of 29.7 dB and 14.2 dB was achieved with 2 mm sample thickness. Nimbalkar et al.
[105] formed a composite by optimizing polycarbonate and graphene nanoplatelets (GNP), using the facile solution method, for electromagnetic interference shielding in X-band. Keeping the composite thickness as 1 mm, 35 dB shielding effectiveness was achieved, where, by increasing the thickness up to 2 mm, 47 dB shielding effectiveness was achieved, indicating that the increase in the thickness directly enhances the shielding effectiveness. Hamidinejad et al.
[106] examined lightweight high-density polyethylene (HDPE) with graphene nanoplatelets composites which were fabricated using the supercritical fluid and injection moulding process. The shielding effectiveness of 31.6 dB was achieved in K-band. Lu et al.
[107] fabricated ethylene propylene diene monomer rubber (EPDM) with graphene nanoplatelets loading to observed EMI shielding effectiveness in X-band and Ku-band. The results showed that with 8 wt.% of GNP, keeping thickness 0.3 mm, 33 dB shielding effectiveness was achieved in X-band, whereas, in Ku-band, 35 dB shielding effectiveness was achieved.
Zdrojek et al.
[108] conducted a study on sub-terahertz radiation shielding by using a graphene-based plastic absorber where PDMS polymer was used. It was observed that being lightweight and nonconductive, graphene-based composites can absorb 99.99% of electromagnetic waves, whereas most metal-based composites simply redirect the radiations. Li et al.
[109] formed a copper-coated RGO@PDMS polymer composite by the Hummers method, where a shielding effectiveness of 74.2 dB was achieved in the X-band frequency range. Ni et al.
[110] synthesized a graphene aerogel (GA) with PDMS polymer, where shielding effectiveness of 60 dB was achieved within the frequency range of 2–18 GHz. In another study conducted by Fang et al.
[111], a 3D-graphene network combined with PDMS was used for high performance EMI shielding. With this combination, 6100 S/m electrical conductivity was achieved even with a low graphene loading of 1.2 wt.%. Also, around 40 and 90 dB, EMI shielding effectiveness was attained in the X-band range when the thickness was kept as 0.25 and 0.75 mm. It is noteworthy that with a 1.2 wt.% loading level, a 256% increase was observed in the tensile strength of the composite. Fang et al.
[111] formed a composite of in-situ grown hollow Fe
3O
4 with graphene foam (GF) and PDMS by using the solvothermal method for high EMI shielding effectiveness. The results showed that 70.37 dB shielding effectiveness was achieved in the X-band frequency. Nguyen et al.
[112] worked on multifunctional broadband EMI shielding skins using MXene(Ti
3C
2T
X)/graphene/PDMS composites. MXene is a newly developed shielding material that provides high shielding effectiveness
[113]. Fe
3O
4 nanoparticles added with Ti
3C
2T
X was coated on graphene foams, where the thickness was kept as 1 mm. The results revealed that an excellent EMI shielding effectiveness was achieved in X-band with 80 dB, whereas, in Ka-band, 77 dB shielding effectiveness was achieved. Liang et al.
[114] optimized flexible polyvinylidene fluoride (PVDF) with high-aligned graphene nanosheets and Ni nanochains for EMI shielding. With sample thickness kept as 0.5 mm in K-band range, 43.3 dB shielding effectiveness was achieved. Whereas, by increasing the thickness up to 0.7 mm, 51.4 dB shielding effectiveness was achieved within the same frequency range. Sharma et al.
[115] grow copper sulphide (CuS) flowers on graphene oxide and later mix it with PVDF polymer. The composites showed shielding effectiveness up to −25 dB at the 12–18 GHz frequency range. Multi-layered graphene nanosheets synthesized with Fe
3O
4 and PVDF showed better results where shielding effectiveness of 52 dB was achieved at X-band frequency range while keeping the sample thickness as 0.3 mm
[116]. With in-situ growth, RGO and hematite nanohybrids were synthesized with the addition of PVDF. While keeping its loading as 5 wt.%, the maximum absorbing value of −43.97 dB was achieved at 5 GHz
[117]. Liang et al.
[118] synthesized graphene (Gn) and silicon carbide nanowires (SiCnw) with PVDF via electrostatic assembly and solution casting method. Shielding effectiveness of 32.5 dB was achieved with 1.2 mm sample thickness when tested in the X-band frequency range. Sabira et al.
[119] synthesized PVDF with graphene nanocomposite via a solution casting method. Shielding effectiveness of 47 dB was achieved within the X-band frequency range with 20 µm thickness. Qi et al.
[120] worked on the three-layered sandwich structure of PVDF, graphene nanoplatelets, nickel (Ni) and carbon nanotubes (CNT). The composite was tested for a three-layered and six-layered structure where shielding effectiveness of 41.8 dB and 46.4 dB was achieved at 15 GHz with a fixed thickness of 0.6 mm. Gargama et al.
[121] synthesized PVDF with nanocrystalline iron (n-Fe) to form a shielding composite which was tested within the X-band frequency range. The composite provided shielding effectiveness of 40.21 dB with a 1.93 mm thickness sample. PVDF was also synthesized with ferrosoferric oxide decorated polyaniline/single wall carbon nanohorn (PFC) to form a shielding composite. A reflection loss of −29.7 dB appeared within the Ku-band with 2 mm thickness
[122].
Liang et al.
[114] optimized 3D copper nanowires-thermally annealed graphene aerogel (CuNWs-TAGA) with epoxy by a thermal annealing method. While keeping the loading of CuNWs-TAGA as 7.2 wt.%, shielding effectiveness was achieved up to 47 dB in the X-band frequency range. Wu et al.
[123] synthesized RGO modified carbon fibre (RGO-CF) with the addition of epoxy (EP) using chemical reduction and electrophoretic deposition methods. With a thickness of 3–5 mm, the maximum shielding effectiveness of 37.6 dB was achieved within the X-band frequency range. Liu et al.
[124] synthesized 3D network porous graphene nanoplatelets (GNP) with Fe
3O
4 and epoxy to form a shielding composite. With 7 wt.% loading of GNP and Fe
3O
4, 37.03 dB shielding effectiveness was achieved in the X-band frequency range. A three-phase composite (graphite nanoplatelets (GNP)/carbonyl iron (Fe)/epoxy) was fabricated using a sonication method. The shielding effectiveness was evaluated from 1–67 GHz with various thickness and loadings. It was observed that with 5 mm thickness of the sample and 5 wt.% GNP loading, the reflection loss came as −78 dB
[125]. Chen et al.
[126] optimized thermally reduced graphene oxide (TGO), magnetic carbonyl iron (CI) and epoxy. The composite was tested in the X-band range where shielding effectiveness of 40 dB was achieved at 4 mm thickness.
Wu et al.
[127] synthesized graphene carbon filler (GCF), with magnetic graphene (MG) and epoxy (EP) to form a shielding composite where GCF loading was 0.5 wt.% and MG loading was 9 wt.%. The testing range was from 18–26 GHz where shielding effectiveness of 51.1 dB was achieved. Jaiswal et al.
[128] synthesized reduced graphene oxide and ferrite nanofiller with epoxy to form a shielding composite. While keeping the epoxy loading as 60 wt.%, a reflection loss of −10.26 dB was achieved with a 3 mm sample thickness in the 2–18 GHz frequency range. Tolvanen et al.
[129] synthesized biodegradable multiphase polylactic acid with biochar and graphite using the hot-pressing method. The composite was tested within the frequency range of K-band where the shielding effectiveness was achieved as 30 dB while using the thin films of 0.25 mm thickness. Barium strontium titanate (BST) was synthesized with RGO and Fe
3O
4 with the addition of polypyrrole polymer via chemical oxidative polymerization. The testing was made within the X-band frequency range where the shielding effectiveness of 48 dB was achieved
[130]. Using the Hummers method, RGO and polyetherimide (PEI) polymer were synthesized to form a shielding composite that was tested in the range of X-band frequency. With the RGO loading of 2.5 wt.%, the maximum shielding effectiveness of 26 dB was achieved
[131].
Hong et al.
[132] evaluated the anisotropic EMI shielding effectiveness of polymer-based composites. Magnetic responsive reduced graphene oxide (Fe
3O
4@RGO) as filler material was synthesized for controlling the orientation of reduced graphene oxide in thermoplastic polyurethane (TPU), where the magnetic field was applied to control the orientation of Fe
3O
4@RGO in in-plane and out-plane direction. A comparison was made between aligned Fe
3O
4@RGO/TPU, random Fe
3O
4@RGO/TPU and random RGO/TPU composites. Results revealed that the random Fe
3O
4@RGO/TPU composites shown an increase in EMI shielding effectiveness by 224% over random RGO/TPU composites. Whereas in-plane aligned Fe
3O
4@RGO showed 250% improved EMI shielding effectiveness over random RGO/TPU composites. The results proved that in determining the EMI shielding effectiveness, the orientation of fillers plays a vital role. Hu et al.
[133] synthesized graphene sponge (G) with polyurethane to form a shielding composite. With a sample thickness of 9 mm and graphene loading 18.7 wt.% shielding effectiveness of 35 dB was achieved in the X-band frequency range. In another study, TPU was synthesized with thermally reduced graphene nanosheets (TRG) via the solution blending method and was tested for its shielding efficiency in Ku-band. The concentration of TRG was from 0 to 5.5 vol% where the maximum total shielding effectiveness was achieved as 32 dB at 5.5 vol% while keeping the sample thickness as 2 mm
[134]. Zubair et al.
[135] synthesized thermally reduced graphene oxide (TRGO) and barium hexaferrite (BaFe) with thermoplastic TPU via the solution casting method. While keeping the sample thickness as 0.25 mm, EMI shielding effectiveness of -61 dB was achieved at 12.5 GHz frequency.
Poly(3,4-ethylenedioxythiophene) (PEDOT) was synthesized with RGO and SrFe
12O
19 nanoparticles through in-situ growth. The EMI shielding composite was tested in the X-band range where the shielding effectiveness of 42.29 dB was achieved with 2.5 mm thickness and 62 dB with 4.66 mm thickness
[136]. PEDOT and RGO were also synthesized with PbTiO3 via chemical oxidative polymerization where the shielding effectiveness of 51.94 dB was achieved within the frequency range of 12.4–18 GHz at 2.5 mm thickness
[137]. In another study PEDOT:PSS was synthesized with Fe
3O
4 and RGO to form a shielding composite. The testing was made within the range of 2–18 GHz where the maximum reflection loss of −61.4 dB was achieved with 3.86 mm sample thickness
[138]. Shukla
[139] synthesized Fe
3O
4 with carbon (C) and polypyrrole (PPy) via hydrothermal and chemical oxidative polymerization to form a shielding composite. It was observed that by keeping the carbon loading up to 2 wt.% and PPy up to 8 wt.%, with the sample thickness 0.8 mm, shielding effectiveness > 28 dB was achieved at 2–8 GHz frequency range. In another study, polypyrrole was used with FeCo and RGO to form a shielding composite via a three-step method. The testing was made within the range of 2–18 GHz where the maximum reflection loss of −40.7 dB was attained at 4.5 GHz when the sample thickness was 2.5 mm
[140]. Yan et al.
[141] optimized three different polymer-based composites i.e., RGO-PANI-NiFe
2O
4, RGO-PPy-NiFe
2O
4 and RGO-PEDOT-NiFe
2O
4. With a material thickness of 2.4 mm, 1.7 mm and 2 mm, a reflection loss of −49.7 dB, −44.8 dB and −45.4 dB was achieved within the 2–18 GHz frequency range. It can be observed that the highest reflection loss was achieved by the PANI polymer composite.
Zuo et al.
[142] synthesized polymethyl methacrylate (PMMA) with graphene and Li
0.35Zn
0.3Fe
2.35O
4 where the testing was made within the range of 2–18 GHz. A reflection loss of −46.1 dB was achieved with 4 mm thickness. Sharif et al.
[143] optimized PMMA and RGO to form a shielding composite where the testing was made within the X-band. With 2.9 mm sample thickness and 2.6 vol% RGO, shielding effectiveness of 63.2 dB was achieved. Joseph et al.
[144] synthesized two different polymer composites for EMI shielding. The first combination was of PMMA with graphene, whereas, the second combination was of polyvinyl chloride (PVC). The shielding effectiveness of 21 dB and 31 dB was achieved within the X-band frequency range with sample thickness as 2 mm and graphene loading as 20 wt.%.
Rao et al.
[145] synthesized Fe
3O
4 with single-layer graphene-assembled porous carbon (SLGAPC) and polyvinyl alcohol (PVA) via the solution casting method. With a thickness of 0.3 mm, the shielding effectiveness of 20 dB was achieved in the X-band frequency range. Khodiri et al.
[146] used PVA, graphene (Gr) and magnetite (Fe
3O
4) to form a shielding composite. With 0.2 mm thickness and little graphene loading of 0.08 wt.%, shielding effectiveness of 40.7 dB was achieved within the X-band frequency range. Li et al.
[147] explored polyether-ether-ketone (PEEK) polymer with GNP and carbonized loofah fibre (CLF) to form a shielding composite. Keeping the testing within X-band, shielding effectiveness of 27.1 dB was achieved with 9 wt.% of CLF. Yadav et al.
[148] used NiFe
2O
4, RGO and polypropylene to form a shielding composite. The testing was in the range of 6-8 GHz where high shielding effectiveness of 29.4 dB was achieved with 2 mm thickness and 5 wt.% RGO loading.
Table 2 shows a summary of polymer-based composites.
Table 2. Summary of Polymer-based composites.
S. No |
Material |
Thickness |
Loading |
Methods |
Frequency |
Shielding Effectiveness |
Year |
Reference |
1 |
PVC/PANI/GNP |
- |
5 wt.% |
Solution processing method |
18–20 GHz |
51 dB |
2019 |
[89] |
2 |
GNP@PANI |
1.5 mm |
- |
In-situ growth |
12 GHz |
−14.5 dB |
2019 |
[90] |
3 |
TiO2/PANI/GO |
3.12 mm |
- |
In-situ growth |
2–18 GHz |
−51.7 dB |
2017 |
[91] |
4 |
Graphene@PANI@TiO2 |
1.5 mm |
- |
1. In-situ growth 2. Hydrothermal method |
2–18 GHz |
−45.4 dB |
2016 |
[92] |
5 |
Graphene@Fe3O4@PANI@WO3 |
4 mm |
- |
1. Hydrothermal method 2. Chemical oxidation polymerization |
9.4 GHz |
−46.7 dB |
2017 |
[93] |
6 |
Graphene@Fe3O4@SiO2@polyaniline |
2.5 mm |
- |
Dilute polymerization |
12.5 GHz |
−40.7 dB |
2015 |
[94] |
7 |
PANI/GO/Fe3O4 |
3.91 mm |
- |
Hummers method |
2–18 GHz |
−53.5 dB |
2015 |
[95] |
8 |
Ag@Graphene/PANI |
- |
5 wt.% |
In-situ growth |
0.4–1.6 GHz |
29.33 dB |
2013 |
[96] |
9 |
Fe3O4/PANI rod/RGO |
3.5 mm |
- |
Facile method |
2–18 GHz |
−33.3 dB |
2019 |
[97] |
10 |
Graphene@NiO@PANI@Ag |
3.5 mm |
- |
1. Hydrothermal method 2. In-situ growth |
2–18 GHz |
−37.5 dB |
2017 |
[98] |
11 |
G-PANI |
1.5 mm |
- |
In-situ growth |
2–18 GHz |
32.5 dB |
2017 |
[99] |
12 |
ℽ-Fe2O3/RGO/PANI |
2.5 mm |
- |
1. Chemical oxidation polymerization 2. In-situ growth |
8–12 GHz |
51 dB |
2014 |
[100] |
13 |
Ti3C2Tx/Fe3O4@PANI |
12.1 µm |
- |
Co-precipitation method |
8–12 GHz |
58.8 dB |
2020 |
[101] |
14 |
PANI/BF/RGO |
- |
- |
Citrate precursor method |
8–12 GHz |
31.1 dB |
2016 |
[102] |
15 |
PANI/Li0.5Fe0.5-xGdxO4 |
2 mm |
- |
In-situ growth |
8–12 GHz |
42 dB |
2019 |
[103] |
16 |
RGO@polystyrene |
- |
3.47 vol% |
High-pressure solid-phase compression moulding |
8–12 GHz |
45.1 dB |
2015 |
[80] |
17 |
Segregated RGO/PS |
2 mm |
10 wt.% |
Hot compressed method |
0–20 GHz |
29.7 dB |
2018 |
[104] |
Conventional RGO/PS |
14.2 dB |
18 |
Polycarbonate/GNP |
1 mm |
- |
Facile solution method |
8–12 GHz |
35 dB |
2018 |
[105] |
2 mm |
- |
47 dB |
19 |
Polyethylene@GNP |
- |
15.6 vol% |
Injection moulding process |
18 and 26.5 GHz |
16 dB |
2018 |
[106] |
19 vol% |
31.6 dB |
3 wt.% |
12 dB |
10 wt.% |
31 dB |
20 |
GNP/EPDM |
0.3 mm |
8 wt.% |
Ultrasonication technique |
8–12 GHz |
33 dB |
2019 |
[107] |
12.4–18 GHz |
35 dB |
21 |
Hollow Fe3O4@GF@PDMS |
- |
4 wt.% |
Solvothermal method |
8–12 GHz |
45 dB |
2020 |
[111] |
8 wt.% |
65 dB |
12 wt.% |
70.3 dB |
22 |
3D Graphene Network@PDMS |
0.25 mm |
1.2 wt.% |
Chemical vapor deposition |
8–12 GHz |
40 dB |
2020 |
[111] |
0.75 mm |
90 dB |
23 |
MXene(Ti3C2TX)/graphene/PDMS |
1 mm |
- |
Chemical vapor deposition |
8–12 GHz |
80 dB |
2020 |
[112] |
26.5–40 GHz |
77 dB |
24 |
Graphene flakes@PDMS |
- |
0.1 wt.% |
Mechanical mixing |
0.6 THz |
6.5 dB |
2018 |
[108] |
3 wt.% |
12 dB |
10 wt.% |
31 dB |
25 |
Cu@RGOFM@PDMS |
0.5 mm |
- |
Hummers method |
8–12 GHz |
74.2 dB |
2020 |
[109] |
26 |
GA/PDMS |
2.5 mm |
- |
1. Ultrasonication technique 2. Hydrothermal method |
2–18 GHz |
60 dB |
2020 |
[110] |
27 |
Ni@GNS@PVDF |
0.5 mm |
- |
Ultrasonication technique |
18–26 GHz |
43.3 dB |
2020 |
[114] |
0.7 mm |
51.4 dB |
28 |
RGO@CuS@PVDF |
1 mm |
- |
Hydrothermal method |
12–18 GHz |
−25 dB |
2020 |
[115] |
29 |
GNSs-Fe3O4/PVDF |
0.3 mm |
- |
Facile layer-by-layer coating |
8–12 GHz |
52 dB |
2020 |
[116] |
30 |
RGO@Hematite/PVDF |
- |
5 wt.% |
In-situ growth |
2–18 GHz |
−43.97 dB |
2014 |
[117] |
31 |
Gn/SiCnw/PVDF |
1.2 mm |
- |
1. Electrostatic assembly 2. Solution casting method |
8–12 GHz |
32.5 dB |
2020 |
[118] |
32 |
PVDF/graphene |
20 µm |
15 wt.% |
Solution casting method |
8–12 GHz |
47 dB |
2018 |
[119] |
33 |
PVDF/GNP-Ni-CNT |
0.6 mm |
- |
Solvent casting method |
12–18 GHz |
46.4 dB |
2020 |
[120] |
34 |
PVDF/n-Fe |
1.93 mm |
- |
Hot-moulding process |
12–18 GHz |
40.21 dB |
2016 |
[121] |
35 |
PVDF/PFC |
2 mm |
1 wt.% |
Solution blending process |
12–18 GHz |
−29.7 dB |
2017 |
[122] |
36 |
CuNWs-TAGA/Epoxy |
- |
7.2 wt.% |
Thermal annealing method |
8–12 GHz |
47 dB |
2020 |
[114] |
37 |
RGO-CF/EP |
3–5 mm |
- |
1. Electrophoretic deposition 2. Chemical reduction |
8–12 GHz |
37.6 dB |
2016 |
[123] |
38 |
GNP/Fe3O4/Epoxy |
- |
7 wt.% |
Co-precipitation method |
8–12 GHz |
37.03 dB |
2019 |
[124] |
39 |
GNP/Fe/Epoxy |
5 mm |
5 wt.% |
Sonication method |
1–65 GHz |
−78 dB |
2020 |
[125] |
40 |
TGO/CI/Epoxy |
4 mm |
- |
Centrifugal mixing method |
8–12 GHz |
40 dB |
2015 |
[126] |
41 |
GCF/MG3/EP |
- |
0.5 wt.%, 9 wt.% |
Hummers Method |
18–26 GHz |
51.1 dB |
2017 |
[127] |
42 |
RGO/PF/Epoxy |
3 mm |
60 wt.% |
Solution mixing method |
2–18 GHz |
−10.26 dB |
2020 |
[128] |
43 |
Polylactic acid/Biochar/Graphite |
0.25 mm |
- |
Hot-pressing method |
18–26.5 GHz |
30 dB |
2019 |
[129] |
44 |
Polypyrrole/BST/RGO/Fe3O4 |
22.8 × 10.03 × 2.5 mm |
- |
Chemical oxidative polymerization |
8–12 GHz |
48 dB |
2018 |
[130] |
45 |
RGO@PEI |
- |
2.5 wt.% |
Hummers Method |
8–12 GHz |
26 dB |
2018 |
[131] |
46 |
Fe3O4@RGO/TPU |
1 mm |
- |
Solution casting method |
8–12 GHz |
~15.51 ± 1.6 dB |
2020 |
[132] |
47 |
G/Polyurethane sponge |
9 mm |
18.7 wt.% |
Hydrothermal method |
8–12 GHz |
35 dB |
2019 |
[133] |
48 |
TPU/TRG |
2 mm |
5.5 vol% |
Solution blending method |
12–18 GHz |
32 dB |
2017 |
[134] |
49 |
BaFe@TRGO@TPU |
0.25 mm |
- |
Solution casting method |
0.1–20 GHz |
−61 dB |
2020 |
[135] |
50 |
PEDOT/RGO/SrFe12O19 |
2.5 mm |
- |
In-situ growth |
8–12 GHz |
42.29 dB |
2019 |
[136] |
4.66 mm |
62 dB |
51 |
PEDOT/RGO/PbTiO3 |
2.5 mm |
- |
Chemical oxidative polymerization |
12.4–18 GHz |
51.94 dB |
2018 |
[137] |
52 |
PEDOT:PSS-Fe3O4-RGO |
3.86 mm |
- |
Hydrothermal method |
2–18 GHz |
−61.4 dB |
2018 |
[138] |
53 |
Fe3O4/C:PPy |
0.8 mm |
2.8 wt.% |
1. Hydrothermal method 2. Chemical oxidative polymerization |
2–8 GHz |
>28 dB |
2019 |
[139] |
54 |
FeCo@RGO@PPy |
2.5 mm |
- |
1. Hydrothermal method 2. In-situ growth |
2–18 GHz |
−40.7 dB |
2017 |
[140] |
55 |
RGO-PANI-NiFe2O4 |
2.4 mm |
- |
1. Hummers method 2. Solvothermal method |
2–18 GHz |
−49.7 dB |
2016 |
[141] |
RGO-PPy-NiFe2O4 |
1.7 mm |
−44.8 dB |
RGO-PEDOT-NiFe2O4 |
2 mm |
−45.4 dB |
56 |
Graphene/Li0.35Zn0.3Fe0.35O4/PMMA |
4 mm |
- |
3D printing method |
2–18 GHz |
−46.1 dB |
2020 |
[142] |
57 |
PMMA/RGO |
2.9 mm |
2.6 vol% |
Self-assembly technique |
8–12 GHz |
63.2 dB |
2017 |
[143] |
58 |
PMMA/graphene |
2 mm |
20 wt.% |
Hot compression method |
8–12 GHz |
21 dB |
2019 |
[144] |
PVC/graphene |
31 dB |
59 |
Fe3O4@SLGAPC@PVA |
0.3 mm |
- |
Solution casting method |
8–12 GHz |
20 dB |
2015 |
[145] |
60 |
PVA/Gr/Fe3O4 |
0.2 mm |
0.08 wt.% |
Hummers method |
8–12 GHz |
40.7 dB |
2020 |
[146] |
61 |
GNP/CLF/PEEK |
- |
9 wt.% |
Compression moulding method |
8–12 GHz |
27.1 dB |
2019 |
[147] |
62 |
NiFe2O4-RGO-Polypropylene |
2 mm |
5 wt.% |
1. Hummers method 2. Hot press method |
6–8 GHz |
29.4 dB |
2019 |
[148] |