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Research Article

Porous Ti3C2Tx MXene nanosheets sandwiched between polyimide fiber mats for electromagnetic interference shielding

Wenhao Liang, Juntao Wu( ), Shan Zhang, Pei-Yan Zhao, Yi Cong, Yongqiang Guo( ), Guang-Sheng Wang( )
Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, China
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Graphical Abstract

The polyimide (PI)/porous-MXene/PI composite film with excellent comprehensive performance was successfully prepared using electrospinning and vacuum filtration methods. The composite film achieves an electromagnetic interference (EMI) shielding effectiveness of 48.8 dB in X-band (8.2–12.4 GHz), and it also shows lightweight, flexibility, and thermal insulation.

Abstract

With the rapid development of wireless communication technology and electronic devices, the issue of electromagnetic interference (EMI) is becoming increasingly severe. Developing a new and flexible electromagnetic interference shielding material has become a challenging task. Here, a sandwich-structured EMI shielding composite film was prepared using electrospinning and vacuum filtration methods. In this process, a porous MXene was synthesized through a reaction with cobalt acetate and served as the intermediate layer in the composite film to shield electromagnetic waves. The electrospun polyimide (PI) fibers were used as the top and bottom layers of the composite film, which can protect the porous MXene from oxidation. This lightweight and flexible composite film integrates electromagnetic interference shielding and thermal insulation capabilities, showing excellent comprehensive performance. The composite film achieves an EMI shielding effectiveness of 48.8 dB in X-band (8.2–12.4 GHz), and absolute shielding effectiveness of the composite film reached a satisfying 4142.43 (dB·cm2)/g. Owing to the design of a multi-layer porous structure, the density of the composite film is 0.65 g/cm3. Furthermore, the thermal conductivity of the film is 0.042 W/(m·K) due to the clamping of electrospun PI fibers, showing excellent thermal insulation performance. Additionally, the composite film exhibits excellent high and low-temperature resistance. In summary, this work provides a feasible strategy for preparing a lightweight polymer-based EMI shielding film.

Keywords

porous MXenepolyimideelectromagnetic interference shieldingthermal insulation

Electronic Supplementary Material

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References

[1]

Wei, C. H.; Shi, L. Z.; Li, M. Q.; He, M. K.; Li, M. J.; Jing, X. R.; Liu, P. B.; Gu, J. W. Hollow engineering of sandwich NC@Co/NC@MnO2 composites toward strong wideband electromagnetic wave attenuation. J. Mater. Sci. Technol. 2024, 175, 194–203.
Crossref Google Scholar
[2]

Jiang, Z. Y.; Gao, Y. J.; Pan, Z. H.; Zhang, M. M.; Guo, J. H.; Zhang, J. W.; Gong, C. H. Pomegranate-like ATO/SiO2 microspheres for efficient microwave absorption in wide temperature spectrum. J. Mater. Sci. Technol. 2024, 174, 195–203.
Crossref Google Scholar
[3]
Wang, J. E.; Song, T. L.; Ming, W.; Yele, M. X.; Chen, L. F.; Zhang, H.; Zhang, X. J.; Liang, B. L.; Wang, G. S. High MXene loading, nacre-inspired MXene/ANF electromagnetic interference shielding composite films with ultralong strain-to-failure and excellent Joule heating performance. Nano Res., in press, https://doi.org/10.1007/s12274-023-6232-y.
Crossref
[4]

Yang, J. M.; Chen, Y. J.; Yan, X.; Liao, X.; Wang, H.; Liu, C.; Wu, H.; Zhou, Y. Y.; Gao, H.; Xia, Y. Y. et al. Construction of in-situ grid conductor skeleton and magnet core in biodegradable poly (butyleneadipate-co-terephthalate) for efficient electromagnetic interference shielding and low reflection. Compos. Sci. Technol. 2023, 240, 110093.
Crossref Google Scholar
[5]

Yang, J. M.; Wang, H.; Zhang, Y. L.; Zhang, H. X.; Gu, J. W. Layered structural PBAT composite foams for efficient electromagnetic interference shielding. Nano-Micro Lett. 2024, 16, 31.
Crossref Google Scholar
[6]

Zhao, J.; Li, M.; Gao, X. G. Construction of SnO2 nanoparticle cluster@PANI core–shell microspheres for efficient X-band electromagnetic wave absorption. J. Alloys Compd. 2022, 915, 165439.
Crossref Google Scholar
[7]
Zhao, J.; Gu, Z.; Zhang, Q. G. Stacking MoS2 flower-like microspheres on pomelo peels-derived porous carbon nanosheets for high-efficient X-band electromagnetic wave absorption. Nano Res., in press, https://doi.org/10.1007/s12274-023-6090-3.
Crossref
[8]

Zhu, L. L.; Mo, R.; Yin, C. G.; Guo, W. Y.; Yu, J. H.; Fan, J. C. Synergistically constructed electromagnetic network of magnetic particle-decorated carbon nanotubes and MXene for efficient electromagnetic shielding. ACS Appl. Mater. Interfaces 2022, 14, 56120–56131.
Crossref Google Scholar
[9]

Zhang, S.; Wu, J. T.; Liu, J. G.; Yang, Z.; Wang, G. S. Ti3C2T x MXene nanosheets sandwiched between Ag nanowire-polyimide fiber mats for electromagnetic interference shielding. ACS Appl. Nano Mater. 2021, 4, 13976–13985.
Crossref Google Scholar
[10]

Liang, Q. Q.; Wang, L.; Qi, X. S.; Peng, Q.; Gong, X.; Chen, Y. L.; Xie, R.; Zhong, W. Hierarchical engineering of CoNi@air@C/SiO2@polypyrrole multicomponent nanocubes to improve the dielectric loss capability and magnetic-dielectric synergy. J. Mater. Sci. Technol. 2023, 147, 37–46.
Crossref Google Scholar
[11]

Xiang, L. L.; Qi, X. S.; Rao, Y. C.; Wang, L.; Gong, X.; Chen, Y. L.; Peng, Q.; Zhong, W. A simple strategy to develop heterostructured carbon paper/Co nanoparticles composites with lightweight, tunable and broadband microwave absorption. Mater. Today Phys. 2023, 34, 101030.
Crossref Google Scholar
[12]

Zhang, Y. L.; Ruan, K. P.; Guo, Y. Q.; Gu, J. W. Recent advances of MXenes-based optical functional materials. Adv. Photonics Res. 2023, 4, 2300224.
Crossref Google Scholar
[13]

He, P.; Cao, M. S.; Cai, Y. Z.; Shu, J. C.; Cao, W. Q.; Yuan, J. Self-assembling flexible 2D carbide MXene film with tunable integrated electron migration and group relaxation toward energy storage and green EMI shielding. Carbon 2020, 157, 80–89.
Crossref Google Scholar
[14]

Liu, H. G.; Wang, Z.; Yang, Y. J.; Wu, S. Q.; Wang, C. K.; You, C. Y.; Tian, N. Thermally conductive MWCNTs/Fe3O4/Ti3C2T x MXene multi-layer films for broadband electromagnetic interference shielding. J. Mater. Sci. Technol. 2022, 130, 75–85.
Crossref Google Scholar
[15]

Gong, K. J.; Peng, Y. M.; Liu, A.; Qi, S. H.; Qiu, H. Ultrathin carbon layer coated MXene/PBO nanofiber films for excellent electromagnetic interference shielding and thermal stability. Compos. Part A: Appl. Sci. Manuf. 2024, 176, 107857.
Crossref Google Scholar
[16]

Jia, T. M.; Qi, X. S.; Wang, L.; Yang, J. L.; Gong, X.; Chen, Y. L.; Qu, Y. P.; Peng, Q.; Zhong, W. Constructing mixed-dimensional lightweight flexible carbon foam/carbon nanotubes-based heterostructures: An effective strategy to achieve tunable and boosted microwave absorption. Carbon 2023, 206, 364–374.
Crossref Google Scholar
[17]

Zhang, Y. L.; Ma, Z. L.; Ruan, K. P.; Gu, J. W. Multifunctional Ti3C2T x -(Fe3O4/polyimide) composite films with Janus structure for outstanding electromagnetic interference shielding and superior visual thermal management. Nano Res. 2022, 15, 5601–5609.
Crossref Google Scholar
[18]

Xu, H. J.; Fan, J. X.; Su, H.; Liu, C. F.; Chen, G.; Dall’Agnese, Y.; Gao, Y. Metal ion-induced porous MXene for all-solid-state flexible supercapacitors. Nano Lett. 2023, 23, 283–290.
Crossref Google Scholar
[19]

Shen, X.; Kim, J. K. Graphene and MXene-based porous structures for multifunctional electromagnetic interference shielding. Nano Res. 2023, 16, 1387–1413.
Crossref Google Scholar
[20]

Zeng, Z. H.; Wu, N.; Wei, J. J.; Yang, Y. F.; Wu, T. T.; Li, B.; Hauser, S. B.; Yang, W. D.; Liu, J. R.; Zhao, S. Y. Porous and ultra-flexible crosslinked MXene/polyimide composites for multifunctional electromagnetic interference shielding. Nano-Micro Lett. 2022, 14, 59.
Crossref Google Scholar
[21]

Zhang, Y. L.; Ruan, K. P.; Shi, X. T.; Qiu, H.; Pan, Y.; Yan, Y.; Gu, J. W. Ti3C2T x /rGO porous composite films with superior electromagnetic interference shielding performances. Carbon 2021, 175, 271–280.
Crossref Google Scholar
[22]

Sun, K.; Wang, F.; Yang, W. K.; Liu, H.; Pan, C. F.; Guo, Z. H.; Liu, C. T.; Shen, C. Y. Flexible conductive polyimide fiber/MXene composite film for electromagnetic interference shielding and joule heating with excellent harsh environment tolerance. ACS Appl. Mater. Interfaces 2021, 13, 50368–50380.
Crossref Google Scholar
[23]

Zhang, Y.; Gao, Q.; Sheng, X. Z.; Zhang, S.; Chen, J. J.; Ma, Y.; Qin, J. B.; Zhao, Y. S.; Shi, X. T.; Zhang, G. C. Flexible, robust, sandwich structure polyimide composite film with alternative MXene and Ag NWs layers for electromagnetic interference shielding. J. Mater. Sci. Technol. 2023, 159, 194–203.
Crossref Google Scholar
[24]

Zhuo, L. H.; Cai, Y. L.; Shen, D.; Gou, P. F.; Wang, M. J.; Hu, G.; Xie, F. Anti-oxidation polyimide-based hybrid foams assembled with bilayer coatings for efficient electromagnetic interference shielding. Chem. Eng. J. 2023, 451, 138808.
Crossref Google Scholar
[25]

Zhang, Y. L.; Ruan, K. P.; Zhou, K.; Gu, J. W. Controlled distributed Ti3C2T x hollow microspheres on thermally conductive polyimide composite films for excellent electromagnetic interference shielding. Adv. Mater. 2023, 35, 2211642.
Crossref Google Scholar
[26]

Zhang, S.; Wu, J. T.; Liang, W. H.; Zhao, P. Y.; Wang, H. Y.; Cong, Y.; Wang, G. S. Flexible and multifunctional polyimide-based composite films by self-reducing reaction for electromagnetic interference shielding in extreme environments. Carbon 2023, 212, 118103.
Crossref Google Scholar
[27]

Ma, C.; Mai, T.; Wang, P. L.; Guo, W. Y.; Ma, M. G. Flexible MXene/nanocellulose composite aerogel film with cellular structure for electromagnetic interference shielding and photothermal conversion. ACS Appl. Mater. Interfaces 2023, 15, 47425–47433.
Crossref Google Scholar
[28]

Liang, C. B.; Qiu, H.; Zhang, Y. L.; Liu, Y. Q.; Gu, J. W. External field-assisted techniques for polymer matrix composites with electromagnetic interference shielding. Sci. Bull. 2023, 68, 1938–1953.
Crossref Google Scholar
[29]

Oliveira, F. M.; Azadmanjiri, J.; Wang, X. H.; Yu, M. H.; Sofer, Z. Structure design and processing strategies of MXene-based materials for electromagnetic interference shielding. Small Methods 2023, 7, 2300112.
Crossref Google Scholar
[30]

Chen, Q. Q.; Fan, B. B.; Zhang, Q. P.; Wang, S.; Cui, W.; Jia, Y. C.; Xu, S. K.; Zhao, B.; Zhang, R. Design of 3D lightweight Ti3C2T x MXene porous film with graded holes for efficient electromagnetic interference shielding performance. Ceram. Int. 2022, 48, 14578–14586.
Crossref Google Scholar
[31]

Zhang, H. B.; Yan, Q.; Zheng, W. G.; He, Z. X.; Yu, Z. Z. Tough graphene-polymer microcellular foams for electromagnetic interference shielding. ACS Appl. Mater. Interfaces 2011, 3, 918–924.
Crossref Google Scholar
[32]

Cao, W. T.; Chen, F. F.; Zhu, Y. J.; Zhang, Y. G.; Jiang, Y. Y.; Ma, M. G.; Chen, F. Binary strengthening and toughening of MXene/cellulose nanofiber composite paper with nacre-inspired structure and superior electromagnetic interference shielding properties. ACS Nano 2018, 12, 4583–4593.
Crossref Google Scholar
[33]

Chen, Y. M.; Pang, L.; Li, Y.; Luo, H.; Duan, G. G.; Mei, C. T.; Xu, W. H.; Zhou, W.; Liu, K. M.; Jiang, S. H. Ultra-thin and highly flexible cellulose nanofiber/silver nanowire conductive paper for effective electromagnetic interference shielding. Compos. Part A: Appl. Sci. Manuf. 2020, 135, 105960.
Crossref Google Scholar
[34]

Tan, H. X.; Gou, J. R.; Zhang, X.; Ding, L.; Wang, H. H. Sandwich-structured Ti3C2T x -MXene/reduced-graphene-oxide composite membranes for high-performance electromagnetic interference and infrared shielding. J. Membr. Sci. 2023, 675, 121560.
Crossref Google Scholar
[35]

Xie, F.; Jia, F. F.; Zhuo, L. H.; Lu, Z. Q.; Si, L. M.; Huang, J. Z.; Zhang, M. Y.; Ma, Q. Ultrathin MXene/aramid nanofiber composite paper with excellent mechanical properties for efficient electromagnetic interference shielding. Nanoscale 2019, 11, 23382–23391.
Crossref Google Scholar
[36]

Shahzad, F.; Alhabeb, M.; Hatter, C. B.; Anasori, B.; Hong, S. M.; Koo, C. M.; Gogotsi, Y. Electromagnetic interference shielding with 2D transition metal carbides (MXenes). Science 2016, 353, 1137–1140.
Crossref Google Scholar
[37]

Xu, H. L.; Yin, X. W.; Li, X. L.; Li, M. H.; Liang, S.; Zhang, L. T.; Cheng, L. F. Lightweight Ti2CT x MXene/poly(vinyl alcohol) composite foams for electromagnetic wave shielding with absorption-dominated feature. ACS Appl. Mater. Interfaces 2019, 11, 10198–10207.
Crossref Google Scholar
[38]

Chen, J.; Liao, X.; Xiao, W.; Yang, J. M.; Jiang, Q. Y.; Li, G. X. Facile and green method to structure ultralow-threshold and lightweight polystyrene/MWCNT composites with segregated conductive networks for efficient electromagnetic interference shielding. ACS Sustainable Chem. Eng. 2019, 7, 9904–9915.
Crossref Google Scholar
[39]

Cheng, H. R.; Pan, Y. M.; Chen, Q.; Che, R. C.; Zheng, G. Q.; Liu, C. T.; Shen, C. Y.; Liu, X. H. Ultrathin flexible poly(vinylidene fluoride)/MXene/silver nanowire film with outstanding specific EMI shielding and high heat dissipation. Adv. Compos. Hybrid Mater. 2021, 4, 505–513.
Crossref Google Scholar
[40]

Zeng, Z. H.; Jin, H.; Chen, M. J.; Li, W. W.; Zhou, L. C.; Zhang, Z. Lightweight and anisotropic porous MWCNT/WPU composites for ultrahigh performance electromagnetic interference shielding. Adv. Funct. Mater. 2016, 26, 303–310.
Crossref Google Scholar
[41]

Lu, Y. M.; Zhao, X. N.; Lin, Y.; Li, P.; Tao, Y.; Wang, Z. Q.; Ma, J. G.; Xu, H. Y.; Liu, Y. C. Lightweight MXene/carbon composite foam with hollow skeleton for air-stable, high-temperature-resistant and compressible electromagnetic interference shielding. Carbon 2023, 206, 375–382.
Crossref Google Scholar
[42]

Wang, K. F.; Chen, C.; Zheng, Q. T.; Xiong, J.; Liu, H. Z.; Yang, L.; Chen, Y. J.; Li, H. Multifunctional recycled carbon fiber-Ti3C2T x MXene paper with superior electromagnetic interference shielding and photo/electro-thermal conversion performances. Carbon 2022, 197, 87–97.
Crossref Google Scholar
[43]

Jiang, Y. Q.; Ru, X. L.; Che, W. B.; Jiang, Z. H.; Chen, H. L.; Hou, J. F.; Yu, Y. M. Flexible, mechanically robust and self-extinguishing MXene/wood composite for efficient electromagnetic interference shielding. Compos. Part B: Eng. 2022, 229, 109460.
Crossref Google Scholar
[44]

Chu, N.; Luo, C. J.; Chen, X. S.; Li, L. X.; Liang, C. B.; Chao, M.; Yan, L. K. Ti3C2T x MXene/polyimide composites film with excellent mechanical properties and electromagnetic interference shielding properties. J. Alloys Compd. 2023, 955, 170241.
Crossref Google Scholar
[45]

Song, W. L.; Guan, X. T.; Fan, L. Z.; Cao, W. Q.; Wang, C. Y.; Zhao, Q. L.; Cao, M. S. Magnetic and conductive graphene papers toward thin layers of effective electromagnetic shielding. J. Mater. Chem. A 2015, 3, 2097–2107.
Crossref Google Scholar
[46]

Li, Y.; Pei, X. L.; Shen, B.; Zhai, W. T.; Zhang, L. H.; Zheng, W. G. Polyimide/graphene composite foam sheets with ultrahigh thermostability for electromagnetic interference shielding. RSC Adv. 2015, 5, 24342–24351.
Crossref Google Scholar
[47]

Li, X. L.; Sheng, X. X.; Fang, Y.; Hu, X. P.; Gong, S.; Sheng, M. J.; Lu, X.; Qu, J. P. Wearable Janus-type film with integrated all-season active/passive thermal management, thermal camouflage, and ultra-high electromagnetic shielding efficiency tunable by origami process. Adv. Funct. Mater. 2023, 33, 2212776.
Crossref Google Scholar
[48]

Zhao, W. W.; Xu, H. T.; Zhao, J. D.; Zhu, X. J.; Lu, Y. Y.; Ding, C. B.; He, W. J.; Bian, J.; Liu, L. L.; Ma, L. F. et al. Flexible, lightweight and multi-level superimposed titanium carbide films for enhanced electromagnetic interference shielding. Chem. Eng. J. 2022, 437, 135266.
Crossref Google Scholar
[49]

Jiang, X. Y.; Zhao, Z. X.; Zhou, S. T.; Zou, H. W.; Liu, P. B. Anisotropic and lightweight carbon/graphene composite aerogels for efficient thermal insulation and electromagnetic interference shielding. ACS Appl. Mater. Interfaces 2022, 14, 45844–45852.
Crossref Google Scholar
[50]

Guo, Z. Z.; Ren, P. G.; Wang, J.; Hou, X.; Tang, J. H.; Liu, Z. B.; Chen, Z. Y.; Jin, Y. L.; Ren, F. Methylene blue adsorption derived thermal insulating N,S-co-doped TiC/carbon hybrid aerogel for high-efficient absorption-dominant electromagnetic interference shielding. Chem. Eng. J. 2023, 451, 138667.
Crossref Google Scholar
[51]

Li, D. D.; Pu, X.; Hu, P.; Han, M. N.; Xin, W.; Ma, M. G. Multifunctional Ti3C2T x MXene/montmorillonite/cellulose nanofibril films for electromagnetic interference shielding, photothermal conversion, and thermal insulation. Cellulose 2023, 30, 3793–3805.
Crossref Google Scholar
[52]

Zhang, H. M.; Zhang, G. C.; Gao, Q.; Tang, M.; Ma, Z. L.; Qin, J. B.; Wang, M. Y.; Kim, J. K. Multifunctional microcellular PVDF/Ni-chains composite foams with enhanced electromagnetic interference shielding and superior thermal insulation performance. Chem. Eng. J. 2020, 379, 122304.
Crossref Google Scholar
[53]

Guo, Y. B.; Vokhidova, N. R.; Wang, Q.; Lan, B. J.; Lu, Y. X. Lightweight and thermal insulation fabric-based composite foam for high-performance electromagnetic interference shielding. Mater. Chem. Phys. 2023, 303, 127787.
Crossref Google Scholar
[54]

Patle, V. K.; Mehta, Y.; Dwivedi, N.; Mondal, D. P.; Srivastava, A. K.; Kumar, R. Thermal insulating and fire-retardant lightweight carbon-slag composite foams towards absorption dominated electromagnetic interference shielding. Sustain. Mater. Technol. 2022, 33, e00453.
Crossref Google Scholar
[55]

Liu, H. B.; Fu, R. L.; Su, X. Q.; Wu, B. Y.; Wang, H.; Xu, Y.; Liu, X. H. Electrical insulating MXene/PDMS/BN composite with enhanced thermal conductivity for electromagnetic shielding application. Compos. Commun. 2021, 23, 100593.
Crossref Google Scholar
[56]

Liu, C. X.; Ma, Y. N.; Xie, Y. M.; Zou, J. J.; Wu, H.; Peng, S. H.; Qian, W.; He, D. P.; Zhang, X.; Li, B. W. et al. Enhanced electromagnetic shielding and thermal management properties in MXene/aramid nanofiber films fabricated by intermittent filtration. ACS Appl. Mater. Interfaces 2023, 15, 4516–4526.
Crossref Google Scholar
[57]

Liu, Z. X.; Zhang, G. X.; Chen, W. T.; Wang, J. X.; Zhang, B. L.; Zhang, Q. Y. Robust biomimetic Ti3C2T x nanocomposite films enhanced by mussel-inspired polymer for highly efficient electromagnetic shielding and thermal camouflage. Carbon 2022, 196, 410–421.
Crossref Google Scholar
[58]

Tian, L.; Gu, H. D.; Zhang, Q. Q.; You, X.; Wang, M. M.; Yang, J. S.; Dong, S. M. Multifunctional hierarchical metamaterial for thermal insulation and electromagnetic interference shielding at elevated temperatures. ACS Nano 2023, 17, 12673–12683.
Crossref Google Scholar
[59]

Yang, F.; Yao, J. R.; Jin, L. Q.; Huyan, W. J.; Zhou, J. T.; Yao, Z. J.; Liu, P. J.; Tao, X. W. Multifunctional Ti3C2T x MXene/aramid nanofiber/polyimide aerogels with efficient thermal insulation and tunable electromagnetic wave absorption performance under thermal environment. Compos. Part B: Eng. 2022, 243, 110161.
Crossref Google Scholar
[60]

Bai, F.; Wu, J. T.; Gong, G. M.; Guo, L. A flexible, sandwiched high-performance super-insulation fabric. J. Mater. Chem. A 2015, 3, 13198–13202.
Crossref Google Scholar
Nano Research
Volume 17 Issue 3,
March 2024
Pages 2070-2078
DOI: 10.1007/s12274-023-6405-4
Cite this article:
Liang W, Wu J, Zhang S, et al. Porous Ti3C2Tx MXene nanosheets sandwiched between polyimide fiber mats for electromagnetic interference shielding. Nano Research, 2024, 17(3): 2070-2078. https://doi.org/10.1007/s12274-023-6405-4
Topics:
Conductive filmsNanofibersNanosheetsPolymer films Porous materials

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Received: 22 November 2023
Revised: 04 December 2023
Accepted: 04 December 2023
Published: 06 February 2024
© Tsinghua University Press 2024
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