Preparation and properties of reduced graphene oxide-carbon nanotubes aerogel/cotton flexible composite fabric with electromagnetic shielding function

Abstract

The electromagnetic pollution has become a serious problem with the rapid development of electromagnetic industry. The present work prepared an electromagnetic interference (EMI) functional composite fabric. Reduced graphene oxide (rGO)-carbon nanotubes (CNTs) aerogel with three-dimensional (3-D) architecture were coated to the cotton fabric with the assistance of waterborne polyurethane (WPU). The structure of graphene aerogel was affected by the amount of CNTs. Small amount of CNTs is helpful to minish the pore size of aerogel and thus improve the EMI value. However, it has been shown that excess CNTs will destroy the 3-D architecture of graphene aerogel. Result shows that the EMI shielding effectiveness exceeded 35 dB when the weight ratio of rGO and CNTs was 7:3, and EMI value of the corresponding composite fabric samples reached 34 dB. Consequently, excellent EMI results were obtained by the unique 3-D rGO-CNTs aerogel in the case of a small nano-carbon material amount. The present work will be expected to make contributions to the practical application of rGO-CNTs aerogel.

Keywords

reduced graphene oxide-carbon nanotubes aerogel waterborne polyurethane electromagnetic interference shielding flexible composite fabric

Introduction

With the rapid development of electromagnetic communication technology, 5G technology has been commercialized in many countries and facilitates both people’s daily life and industry production [1–3]. However, the electromagnetic pollution has caused negative influences [4–6]. Some certain frequency waves may cause the human cell to resonate which does great harm to our body health [7–9]. In addition, it’s risky to the electromagnetic information leakage and lead to the electromagnetic interference to some precise equipment. Therefore, the research of EMI shielding materials has become a hot topic recently [10–12]. Since the electromagnetic interference (EMI) shielding materials were applied in some situations such as military information command post tent, human electromagnetic protective clothing and the electronic instrument cover, it always requires the flexibility of these materials [13–15]. Thus, a flexible EMI shielding functional fabric was prepared and the related properties were investigated in this research.

The flexible EMI shielding materials has been highly focused at present [16–18]. Metal-knitted fabric and metal-coating fabric were fabricated by some scholars. For example, Kim et al. [19] prepared a Cu nano-particle composite fabric through an underwater plasma method. The fabric showed a decent EMI shielding performance as 38 dB due to the excellent conductive property of copper. Cao et al. [20] fixed the silver nano-particles on the non-weave fabric surface with the assistant of the polydopamine. Results showed that the silver nano-particle/non-weave fabric can not only play the role of EMI shielding but also has the function of antibacteria. However, the preparation process of this method was complex and the cost was high. Moreover, the development of metal-based EMI shielding functional fabric was limited due to the heavy weight, poor chemical stability and high stiffness.

Nano-carbon materials were also applied to fabricate the EMI-shielding fabric. Liu et al. [21] prepared a compound painting with graphene and waterborne polyurethane (WPU). Then the painting was coated onto the fabric surface to get the EMI-shielding function fabric. This composite fabric has an EMI-shielding effectiveness of 22 dB in the frequency range of 0–40 MHz, while the graphene amount is high and it’s difficult to uniformly disperse the graphene in the WPU. Zhang et al. [22] immersed the fabric into graphene aqueous solution. The graphene were fixed on the fabric after the reaction of pyrrole polymerization. The EMI shielding value of the composite fabric reached 25 dB in X-band. Nevertheless, the graphene utilization was not good enough and the bonding strength of the graphene and fabric was also unsatisfactory. Zou et al.[23] prepared a graphene oxide/polyaniline cotton fabric by a layer-by-layer assembling method. The generated fabric reached 19.91 dB after four times assembling of graphene oxide. From the previous works, the current nano-carbon materials applied in the flexible EMI-shielding materials preparation were directly added into the fabric in most cases, leading to the agglomeration of nano-carbon materials and high preparation cost.

To prevent the agglomeration of the nano-carbon materials and also minimize their usage amount, the 3-dimensional rGO hydrogel was firstly covered on the cotton fabric surface, after that the graphene aerogel-cotton composite fabric was obtained after a freeze drying step [24]. The EMI-shielding effectiveness of this composite fabric was over 28 dB with a relatively small graphene amount. Nevertheless, the 3-dimensional porous network structure of the graphene hydrogel was destroyed by the mechanical force, which limited the further improvement of EMI-shielding property to the graphene aerogel-cotton composite fabric.

Based on the previous research of the flexible EMI fabric and our initial attempt of graphene aerogel composite fabric, the new research approach was proposed as follows: the 3-dimensional graphene aerogel structure could be improved by the 2-dimensional CNTs, and for preventing the destruction caused by the mechanical force, the rGO-CNTs aerogel will be fabricated into a certain shape via freeze drying method, and attached the aerogel to the cotton fabric completely, so that the aerogel porous structure could be preserved and its EMI-shielding performance can be maximized.(Figure 1).

Figure 1.

The preparation schematic of rGO-CNTs aerogel/cotton composite fabric.

Experimental section

Materials

The multi-walled carbon nanotubes (MWCNTs), as the conductive additive, were obtained from Chengdu Organic Chemistry Co., LTD (Chengdu, China), with 10–20 nm diameter and 10–30 μm length. The graphite powder with a particle size of <50 μm was purchased from Sinopharm Chemical Group Chemical Reagent Co. LTD. KMnO4 (analytical grade), NaNO₃ (analytical grade), H₂SO₄ (98%), H₂O₂ (35%), ascorbic acid (analytical grade), polyvinyl pyrrolidone (PVP, analytical grade) and ethyl alcohol (analytical grade) were all purchased from Shanghai Sinopharm Group Reagent Co. LTD. Waterborne polyurethane (WPU, 40% solid content) was purchased from Sinopac Chemical Reagent Co., LTD Silicon-based low bubble permeable agent (Product name:JFC) was obtained from Guangzhou zhongwan new material Co., LTD. The cotton fabric (100 weft/cm, 150 warp/cm, 295 g/m²) and deionized water were made in our laboratory.

The preparation of rGO

The graphene oxide was prepared by the modified Hummers method [25]. The experiment details of the GO preparation were represented in our previous work [24]. The obtained GO were crushed into powder by a shredder for the convenient reservation.

The surface modification of CNTs

For the improvement of CNTs surface activity and the dispersibility in aqueous solution, CNTs were required to be modified by mixed acid (H₂SO₄: HNO₃ = 3:1). CNTs were added into the mixed acid (with 800 r/min, 90°C) and for 90 min. The modified CNTs were washed by deionized water three times, and then heated in a vacuum oven at 60°C for 12 h.

The preparation of rGO-CNTs aerogel

1 g graphene powder and CNTs with a certain ratio (10:0, 9:1, 8:2, 7:3, 6:4, 5:5) was added in to deionized water, 0.1 g polyvinylpyrrolidone (PVP) was also needed to disperse the graphene and CNTs uniformly in the solution. The uniform graphene/CNTs solution was obtained after 4 h mechanical stirring and 2 h ultrasonic dispersion. There are many oxygen-containing functional groups that exist on the edge sites of both the graphene oxide and modified CNTs. The conductivity property as the most important factor for EMI shielding will be greatly affected by these oxygen-containing functional groups. Ascorbic acid (V_C) was selected as the reducing agent in this experiment, the reduced graphene oxide (rGO) and reduced CNTs (written as CNTs for convenience) solution was put into an oven at 75°C to form the rGO-CNTs hydrogel. Finally, the rGO-CNTs aerogel was obtained after a freeze drying process at -20°C for 36 h. The rGO-CNTs aerogel samples were named to GC-X corresponding to the different rGO and CNTs weight ratio, for example, GC-8 means the ratio of rGO and CNTs was 8:2 in the aerogel.

Pretreatment of cotton fabric

The cotton fabric was cut into a circle (diameter:18 cm) shape. The fabric flexible treatment solution was prepared by 32 g NaOH and 10 mL JFC agent and 800 mL deionized water with mechanical stirring. The cotton fabric was immersed in the solution and heated in 80°C for 2 h. The softened cotton fabric needed to be washed and dried in the last step.

Preparation of rGO-CNTs aerogel-cotton composite fabric

The cotton fabric should be cut into a circle shape which is the same as the rGO-CNTs aerogel. A certain volume of WPU (4 mL/dm², 6 mL/dm², 8 mL/dm², 10 mL/dm²) was coated on the cotton fabric surface first, and then put the rGO-CNTs aerogel with different on the fabric with appropriate pressure to connect them together. Afterwards the aerogel surface should also be covered with a layer of WPU, which prevents the surface destruction of the aerogel. The composite fabric was dried in a vacuum oven (vacuum degree 2 × 10⁴ Pa, 60°C) for 12 h to solidify the WPU, the low pressure is available to the WPU permeate into the aerogel interior and remove the bubbles in the WPU. Finally, the rGO-CNTs aerogel-cotton composite fabric was obtained. The effects of the amount of aerogel on the EMI shielding properties of composite fabrics and the dosage of WPU on the fabric properties were investigated respectively. Aerogel composite fabric samples were named to ACF-X-Y (X: rGO-CNTs aerogel weight percentage in the composite fabric, Y: the WPU dosage in a unit fabric area of 1 dm², for example, ACF-21-8 means aerogel percentage was 21% in the composite fabric and the WPU covered on the fabric was 8 mL/dm²).

Characterization and tests

The morphology of the composite fabric was characterized by field-emission scanning electron microscopy (FESEM) (JEM-2100F, Kabuskiki Kaisha, Japan).

The fabric samples were cut into a rectangle shape of 2 × 1 cm, and both two sides of the sample were affixed by a conductive adhesive electrode. The conductivity resistance (R) was measured by four-probe method (type FT-340, Rooko Instrument Co. LTD, China), and the surface resistivity (ρ) of composite fabric was calculated by equation (1)

ρ= k \times R

(1)

In this equation,

ρ: surface resistivity (Ω·m)

R: the conductivity resistance value (Ω)

k: geometric factor of the electrode, k = 19.8 in this test.

The electromagnetic interference shielding effectiveness of the composite fabric was examined with a typical coaxial-line method by a vector network analyser (MS4644A, Anritsu, Japan) in X-band (8.2–12.4 GHz). Composite fabric samples were cut into a circular ring (outer diameter:7 cm, inner diameter:3 cm) and placed into a French cavity for compaction. The reflection parameters (S₁₁ and S₂₂) and transmission parameters (S₁₂ and S₂₁) were measured by a vector network analyser

It is crucial to the connection strength of the aerogel on the fabric. Therefore, an ultraphonic treated method [24] was applied to test the adhesion fastness of graphene aerogel on the fabric. The fabric samples were cut into 5 cm × 5 cm rectangle, and dried at 70°C for 6 h in an oven, and then got its weight (W₁). After that, the samples were placed into an ultrasonic cleaning machine (KQ-250E, Shanghai Yuezhong Co. LTD, China) with 360 W to ultrasonic shaking for 2 h. Finally, the fabric samples were dried and weighed (W₂) again. The weight retention rate was obtained by the equation below

Weight retention rate = \frac{W_{2}}{W_{1}} \times 100 %

(2)

The fabric air permeability was tested by automatic fabric permeability tester (YG461E, Wenzhou Baien Co. LTD, China) (Supplementary Figure 1).

Results and discussion

Characterization of rGO-CNTs aerogel/cotton composite fabric

rGO-CNTs aerogel plays a role of EMI shielding function in the composite fabric, hence the first priority is the characterization of rGO-CNTs aerogel.

The graphite with multi-layers structure has been exfoliated into a single or few layered graphene as Supplementary Figure 2(a) shows, which proved the successful preparation of graphene. The connection morphology of rGO and CNTs can be observed (Supplementary Figure 2(b) and (c)), CNTs were warped in the interior of graphene or attached on the graphene surface, the CNTs end tail was stretched out of the graphene which may play a role of bridge to link other graphene flakes nearby. The CNTs used in this research were multiwalled carbon nanotubes and the walls layers can be observed in Supplementary Figure 2(d).

The aerogel GC-10 without any CNTs showed a continuous 3-dimensional porous network structure (Figure 2(a)). There are both the large size pores built by the graphene flakes and small size inherent holes in the graphene (average pore size: 43 μm). The average pore size was obviously minimized to 24.6 μm after the introduction of CNTs as GC-7 (Figure 2(b)), it was mainly due to the CNTs electrostatic attraction and intermolecular forces on the graphene surface, thus there will be lots of CNTs end tails extended out of the graphene surface, which facilitated the crosslinking of rGO in the hydrothermal process.

Figure 2.

The SEM images of rGO-CNTs aerogel,(a) GC-10; (b) GC-7; (c) GC-5; (d) Excessive CNTs wrapped on the surface of a graphene sheet, and the optical images of aerogel samples of GC-10 (e) and GC-5 (f).

The pore size reduction also elucidated there will be more carbon network in the unit volume, which was helpful to improve the interior reflection and absorption of the incident waves. The aerogel GC-5 network became broken as exhibit in Figure 2(c). From the enlarged SEM image Figure 2(d), it can be observed that the graphene flakes were covered by the excess CNTs completely, which impede the self-assembling behaviour of graphene in the hydrothermal process. The hydrogel construction was mainly depending on the tangle of CNTs rather than the assembling of graphene flakes. Therefore, the structure destruction of the rGO-CNTs aerogel was mainly caused by the high rGO:CNTs ratio.

Figure 3 exhibits the EMI-shielding effectiveness variation tendency with different rGO and CNTs ratio, the EMI value first increased and then decreased with the larger content of CNTs, the GC-7 exhibited the best EMI-shielding effectiveness of 45.4 dB. The average value of GC-10 was 27.9 dB which is lower than most of the rGO-CNTs aerogel, because aerogel construct by the 2-dimensional graphene flakes has much cavity structure and large holes inside the aerogel, and the connection of each graphene was also very weak, so that the rGO aerogel conductive network was not dense enough. However, the porous network structure was improved after the help of CNTs, the pore size of the aerogel could be minimized by CNTs, so that the inside reflection possibility of electromagnetic waves will be improved. Additionally, the CNTs in the aerogel could also play a role of bridge, which linked both the nearby rGO and CNTs. Therefore, the EMI-shielding value is enhanced by the assistance of CNTs.

Figure 3.

The 3D fitting analysis of EMI SE property variation with different ratio of rGO and CNTs.

Nevertheless, the EMI-shielding value of rGO-CNTs aerogel declined when the rGO:CNTs ratio was <7:3, especially, the EMI-shielding average value was only 22.87 dB as the GC-5 shows, which is lower than the pure rGO aerogel of GC-10. With the increased content of CNTs, the CNTs were easily agglomerated and warped full of the rGO surface, while the aerogel was mainly constructed by the rGO. Therefore, too much CNTs will greatly affect the porous network architecture of aerogel which lead to the undesirable EMI-shielding result of rGO-CNTs aerogel.

Characterization of flexible rGO-CNTs aerogel composite cotton fabric

The aerogel with an rGO and CNTs ratio of 7:3 was adopted to the preparation of rGO-CNTs aerogel/composite cotton fabric.

The flexibility of rGO-CNTs aerogel-cotton composite was retained from the original cotton fabric, and it can be mechanically bent without damage (Figure 4(a)). The fabric surface was covered by a rGO-CNTs layer completely as shown in Figure 4(b), the porous network of aerogel has been fully filled by WPU. The composite fabric hierarchical structure was clearly exhibited by a cross section picture as Figure 4(c), compared to our previous graphene aerogel/cotton fabric [24], the rGO-CNTs aerogel layer kept a very ordered and intact structure which is almost the same as the aerogel before connecting with the fabric. The aerogel fitting method successfully protected the porous network structure from the mechanical destruction.

Figure 4.

(a) The digital picture of rGO-CNTs aerogel-cotton composite fabric; (b) The SEM images of composite fabric surface morphology; (c) The cross section of composite fabric; (d) Enlargement of the aerogel layer cross section coated on cotton fabric (Sample ACF-25-8).

The aerogel interior porous was dense and compact due to the WPU filling and permeation (Figure 4(d)). The edge sites and the cross section outline of aerogel were distinct, which means the WPU filled but did not destroy the aerogel network.

The fastness of the aerogel layer and fabric layer was tested by an ultrasonic oscillation test, and the fastness strength can be reflected by the weight deviation before and after ultrasonic treatment.

A relative low weight retention of 96.3% can be found for the aerogel ACF-27-4 in Figure 5(a). Nevertheless, the weight retention rate was raised with the increased amount of WPU volume, and the higher weight retention reached 98.4% by ACF-27-8. The aerogel layer connection strength was weak when the WPU amount was little, and the aerogel layer was exfoliated. The aerogel layer of sample ACF-27-10 was strong enough to resist the destruction of ultrasonic vibration.

Figure 5.

(a) The weight retention rate of composite fabric with different WPU amount and the pictures of ACF-27-8 (b) and ACF-27-4 (c) after the ultrasonic treatment.

The breathability of composite fabric was in a relatively low level because of the WPU covered on the fibre (Supplementary Figure 3). The interval space existed in the cotton yarns and cotton fibres were plugged up by the WPU polymer (Supplementary Figure 4(b)). Therefore, the air was difficult to flow past the cotton fabric. The low breathability was acceptable for the industrial application but may not be desirable for the human body’s wearable ability.

The mechanical properties like tensile strength (Supplementary Figure 5(a)) and bursting strength (Supplementary Figure 5(b)) were also improved by the increased amount of WPU. However, the fabric flexibility was limited by the permeation of WPU (Supplementary Figure 6).

The surface resistance of rGO-CNTs aerogel-cotton composite fabric declined for the increase amount of aerogel. The conductive network constructed by the graphene and CNTs fit the requirement of EMI shielding perfectly, and the increased aerogel amount built more conductive path in the aerogel porous network, thus the fabric surface resistance was reduced.

The total EMI-shielding effectiveness of rGO-CNTs aerogel-cotton composite fabric increased continuously due to the growing aerogel amount. When the aerogel weight percentage was over 27% the decent EMI-shielding value of more than 34 dB in X-band was obtained, which is far ahead of the 20 dB of the civilian requirements EMI-shielding functional materials baseline [26]. According to the following equation [27,28]

S E_{T} = - 10 \log (\frac{P_{I}}{P_{T}})

(3)

a decent result of >99.96% of the incident waves were calculated.

This EMI shielding result of rGO-CNTs aerogel/composite fabric was not only much better than our previous research of graphene aerogel/cotton composite fabric [24], but also superior to the GO/PPy cotton fabric (25 dB) [29] and rGO/Ti₃C₂T_X MXene fabric (29.04 dB) [30]. The EMI-shielding effectiveness variation tendency was not similar to the graphene aerogel/cotton composite fabric [24], for there is no EMI percolation threshold area. That’s because connection method of the aerogel (the surface area of aerogel was the same with cotton fabric) on the fabric was adhesion with the help of WPU instead of coating the graphene hydrogel by mechanical force. Therefore, the 3 D porous network was virtually the same before and after bonding on the fabric.

The aerogel layer thickness was increased by the growing amount rGO-CNTs aerogel; it also means that the interior reflection chance of elcetromagnetic waves became more dense. The EMI-shielding absorption value shown in Figure 6(c) said that the EMI SE_A was the dominant role in the total EMI SE. The EMI SE_R of different samples was very close for their same aerogel/air interface. The total EMI effectiveness (SE_T) is consisted by two parts, EMI absorption (SE_A) and EMI reflection (SE_R).

S E_{T} = S E_{A} + S E_{R}

(4)

Figure 6.

(a) The surface resistance of rGO-CNTs aerogel-cotton composite fabric; (b) the 3D fitting analysis of total EMI shielding effectiveness of the rGO-CNTs aerogel-cotton composite fabric with different aerogel amount; (c) The absorption EMI shielding value (SEA); (d) The reflection EMI shielding value (SER).

SE_A and SE_R were obtained from calculating the test parameters S₁₁ S₂₁ by the following equations [31–33], as exhibited in Figure 6(c) and Figure 6(d).

S E_{A} = - 10 \log (\frac{T}{1 - R})

(5)

S E_{R} = - 10 \log (1 - R)

(6)

R = {| S_{11} |}^{2}

(7)

T = {| S_{21} |}^{2}

(8)

The incident electromagnetic waves was multi-reflected and absorbed in the aerogel porous network, the power of waves will be exhausted and transferred into heat in the aerogel interior by the dielectric loss. Thanks for the assistant of CNTs, the interior architecture of graphene aerogel was greatly improved.

Both of the graphene and CNTs have excellent electrical properties because of the numerous delocalized π electrons existed in their molecular structure, and the good conductivity is essential to the improvement of EMI shielding result. According to the dielectric loss theory [34–36], inductive current is generated when the conductive material is in an alternating or moving in an electric field caused by the electromagnetic waves, and the inductive current will be transferred in the form of heat.

And based on the requirement of the conductive penetration theory [37–39], the conductive fillers were needed to disperse as evenly as possible to construct a continuous conductive network structure. This is crucial for a composite material to obtain a high EMI-shielding property. The rGO-CNTs aerogel layer connected on the cotton fabric surface played a role of EMI shielding functional filler. The rGO and CNTs were applied to prepare a 3-dimensional porous network structure, which is quite different from the previous work like filler surface coating method or filler solution impregnation method. The aerogel network was protected without mechanical damage because of the full filled WPU. Therefore, the complete aerogel structure satisfied the requirement of the EMI-shielding conductive penetration theory [40–42]. Furthermore, the macro aerogel network was built by the rGO flakes and CNTs. From the TEM image (Supplementary Figure 2(c)), the end tail of CNTs was extended out of the rGO flakes they attached and connected the other nearby rGO or CNTs. Therefore, the conductive pathways were created by the cooperation of rGO and CNTs. Hence, the good electrical property was also improved due to the synergy of rGO and CNTs. As Figure 7 exhibited, rGO-CNTs aerogel-cotton composite fabric with decent EMI-shielding function was due to the 3D aerogel porous network. Furthermore, the aerogel structure was improved and designed by the cooperation of rGO and CNTs.

Figure 7.

The EMI shielding schematic diagram of rGO-CNTs aerogel-cotton composite fabric.

Conclusion

In summary, an rGO-CNTs aerogel-cotton composite fabric with intact aerogel network structure was prepared with the help of WPU. Aerogel with the rGO and CNTs weight ratio of 7:3 exhibits a decent EMI shielding effectiveness of 45.39 dB. In addition, the aerogel (rGO:CNTs 7:3)-cotton composite fabric also demonstrated good EMI-shielding value of 34 dB in X-band when the aerogel weight percentage was 27% owning to the complete aerogel network structure and the synergy of rGO and CNTs. The application of WPU guaranteed enough binding strength of aerogel layer and cotton fabric surface and also increased the mechanical properties like tensile strength and bursting strength. Therefore, the rGO-CNTs aerogel-cotton composite fabric had great application potential in wearable electronics and functional garments.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work was supported by the Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi (TSTAP) [No. 2020CG014], the Postgraduate Education Innovation Project in Shanxi [No. 2020SY466], the National Science Foundation of Shanxi [No. 20210302314], the Students Innovation and Entrepreneurship Training Program Project of Taiyuan University of Technology [No. 202085], the MOE (Ministry of Education in China) Project of Humanities and Social Sciences [No. 18YJC760051] and the Program for the Philosophy and Social Sciences Research of Higher Learning Institutions of Shanxi (PSSR) [No. 201803060].

ORCID iDs

Peng Wang

Man Zhang

References

Kumar

Vats

Pathak

. Harmful effects of 41 and 202 MHz radiations on some body parts and tissues. Indian J Biochem Biophys 2008; 45(4): 269–274.

Wessapan

Srisawatdhisukul

Rattanadecho

. Numerical analysis of specific absorption rate and heat transfer in the human body exposed to leakage electromagnetic field at 915 MHz and2450 MHz. J Heat Trans-TASME 2011; 133(5): 051101.

Zhang

Wang

Liu

, et al. An investigation into the effects of long‐term 50‐Hz power‐frequency electromagnetic field exposure on hematogram, blood chemistry, fibrosis, and oxidant stress status in the liver and the kidney from Sprague-Dawley Rats. Bioelectromagnetics 2020; 41(7): 511–525.

Kim

Nasim

. Human electromagnetic field exposure in 5G at 28 GHz. IEEE Consum Electron Mag 2020; 9(6): 41–48.

Moon

. Health effects of electromagnetic fields on children. Clin Exp Pediatr 2020; 63(11): 422–428.

Starr

Rye

SmithNetmat-Nasser

. Fabrication and characterization of a negative-refractive-index composite metamaterial. Phys Rev B 2004; 70(11).

Numan

Sharawi

. Extraction of material parameters for metamaterials using a full-wave simulator [education column]. IEEE Antennas Propag Mag 2013; 55(5): 202–211.

Zhang

Huang

Liu

. Enhanced electromagnetic wave absorption properties of poly(3,4-ethylenedioxythiophene) nanofiber-decorated graphene sheets by non-covalent interactions. Nano-Micro Letters 2016; 8(12): 131–136.

Sun

, et al. Laminated magnetic graphene with enhanced electromanetic wave absorption properties. J Mater Chem C 2013; 1(14): 765–777.

10.

Yan

, et al. Preparation of graphene aerogel with high mechanical stability and microwave absorption ability via combining surface support of metallic-CNTss and interfacial cross-linking by magnetic nanoparticles. ACS Appl Mater Inter 2019; 11: 10409–10417.

11.

Wang

Zhao

WANG

, et al. Injection-molded microcellular PLA/graphite nanocomposites with dramatically enhanced mechanical and electrical properties for ultra-efficient EMI shielding applications. J Mater Chem C 2018; 6: 6847–6859.

12.

Hooman

Marcelon

Jose

. Recent advances in carbon-based polymer nanocomposites for electromagnetic interference shielding. Prog Mater Sci 2019; 103: 319–373.

13.

Azam

Vijay

Michal

, et al. Copper electroless plating of cotton fabrics after surface activation with deposition of silver and copper nanoparticles. J Phys Chem Solids 2020; 137: 109181.

14.

Zhang

, et al. Lightweight, multifunctional microcellular PMMA/Fe 3 O 4 @MWCNTs nanocomposite foams with efficient electromagnetic interference shielding. Compos A: Appl Sci Manuf 2017; 100: 128–138.

15.

Park

Bae

. Polymer composite containing carbon nanotubes and their applications. Recent Pat Nanotechnol 2017; 11(2): 109–115.

16.

Ates

Eker

. Carbon nanotube-based nanocomposites and their applications. J Adhes Sci Technol 2017; 31(18): 1977–1997.

17.

Sambyal

Iqbal

Hong

, et al. Ultralight and mechanically robust Ti3C2Tx hybrid aerogel reinforced by carbon nanotubes for electromagnetic interference shielding. ACS Appl Mater Inter 2019; 11: 38046–38054.

18.

Voet

. Temperature effect of electrical resistivity of carbon black filled polymers. Rubber Chem Technol 1981; 54(1): 42–50.

19.

Kim

Huh

Hong

. Direct coating of copper nanoparticles on flexible substrates from copper precursors using underwater plasma and their EMI performance. Mater Sci Eng B 2021; 265: 114995.

20.

Gao

Wang

Yue

, et al. Multifunctional cotton non-woven fabrics coated with silver nanoparticles and polymers for antibacterial, superhydrophobic and high performance microwave shielding. J Colloid Interf Sci 2021; 582: 112–123.

21.

Liu

Zhang

, et al. Study on the electromagnetic properties and mechanical properties of graphene/graphite single-layer coating fabric. J Text Sci Eng 2019; 36(2): 1–5.

22.

Zhang

. Polypyrrole/grapphene Oxide Films Based Microwave Absorbing Fabric through Layer-By-Layer Assembly. Shanghai, China: Donghua University, 2015.

23.

Zou

Sun

, et al. Influence of graphene oxide/polyaniline functional film on electromagnetic shielding property of cotton fabrics. J Text Res 2019; 40(8): 109–116.

24.

Wang

Liu

Zhang

, et al. Preparation and properties of graphene aerogel/cotton composite flexible fabric with electromagnetic interference (EMI) shielding function. J Ind Text 2021: 152808372198927. DOI: 10.1177/1528083721989272.

25.

Hummers

Offeman

. Preparation of graphitic oxide. J Am Chem Soc 1958; 80(6): 1339.

26.

Yan

27.

Vineeta

. Role of spin disorder in magnetic and EMI shielding properties of Fe3O4/C/PPy core/shell composites. J Mater Sci 2020; 55: 2826–2835.

28.

Sim

Lee

Kim

, et al. Self-healing graphene oxide-based composite for electromagnetic interference shielding. Carbon 2019; 155: 499–505.

29.

Lan

Zou

Wang

, et al. Multi-reflection-enhanced electromagnetic interference shielding performance of conductive nanocomposite coatings on fabrics. J Colloid Interf Sci 2021; 590: 467–475.

30.

Zheng

Nie

, et al. Multifunctional RGO/Ti3C2Tx MXene fabrics for electrochemical energy storage, electromagnetic interference shielding, electrothermal and human motion detection. Mater Des 2021; 200: 109442.

31.

Gao

Wang

Yue

32.

Zhu

Xing

, et al. Fe nanoparticles and CNTs co-decorated porous carbon/graphene foam composite for excellent electromagnetic interference shielding performance. J Alloys Comp 2020; 820: 153108.

33.

Khodiri

Al-Ashry

El-Shamy

. Novel hybrid nanocomposites based on polyvinyl alcohol/graphene/magnetite nanoparticles for high electromagnetic shielding performance. J Alloys Comp 2020; 847: 156430.

34.

Sichel

. Carbon black-Polymer composites:The Physics of Electrically Conducting composites. New York, NY: Marcel Dekker, 1982.

35.

Rajagopal

Satyam

. Studies on electrical conductivity of insulator‐conductor composites. J Appl Phys 1978; 49(11): 5536–5542.

36.

Zallen

Penchina

. The Physics of Amorphous solids. WILEY, 1983, pp. 862–863.

37.

Stauffer

. Introduction to percolation theory. Phys Today 1985; 40(10): 64.

38.

Sichel

Gittleman

Sheng

. Transport properties of the composite material carbon-poly(vinyl chloride). Phys Rev B 1978; 18(10): 5712–5716.

39.

Carmona

. Conducting filled polymers. Phys A: Stat Mech Appl 1989; 157(1): 461–469.

40.

Wan

Zhu

, et al. Anticorrosive, ultralight, and flexible carbon-wrapped metallic nanowire hybrid sponges for highly efficient electromagnetic interference shielding. Small 2018; 14(27): 1800534.

41.

Huang

Liu

Zhou

, et al. Cellulose composite aerogel for highly efficient electromagnetic interference shielding. J Mater Chem A 2015; 3(93): 4983–4991.

42.

Wang

Kang

, et al. Super-fast fabrication of MXene film through a combination of ion induced gelation and vacuum-assisted filtration. Eng Sci 2021; 15: 57–66.