TRANSITION METAL CARBONITRIDE MXENE FILMS FOR EMI SHIELDING
20210261415 · 2021-08-26
Assignee
Inventors
- Yury GOGOTSI (Philadelphia, PA, US)
- Kanit HANTANASIRISAKUL (Philadelphia, PA, US)
- Chong Min Koo (Seoul, KR)
- Aamir IQBAL (Seoul, KR)
- Soon Man Hong (Seoul, KR)
- Seon Joon Kim (Seoul, KR)
- Seung Sang Hwang (Seoul, KR)
- Kyung Youl Baek (Seoul, KR)
- Albert Lee (Seoul, KR)
- Sangho Cho (Seoul, KR)
Cpc classification
C23C16/30
CHEMISTRY; METALLURGY
H05K9/0088
ELECTRICITY
C01B21/0828
CHEMISTRY; METALLURGY
International classification
Abstract
In an aspect, the present disclosure provides a heat-treated transition metal carbonitride MXene film annealed at high temperatures and a polymer composite comprising the same. In another aspect, the present disclosure provides a method for producing a heat-treated transition metal carbonitride MXene film comprising: obtaining a MXene aqueous solution containing dispersed 2-dimensional (2D) MXenes through an acid etching process; filtering the obtained MXene aqueous solution through a vacuum filtration process to produce a free-standing film; and annealing the produced free-standing film at high temperatures to obtain a heat-treated transition metal carbonitride MXene film. In still another aspect, the present disclosure provides an electromagnetic interference (EMI) shielding method comprising: superposing a coating comprising a heat-treated transition metal carbonitride MXene film on at least one surface of an object in a contact or non-contact manner.
Claims
1. A heat-treated transition metal carbonitride MXene film annealed at 100-500° C.
2. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein the MXene film has a porous structure with laminated transition metal carbonitride 2-dimensional (2D) MXenes.
3. The heat-treated transition metal carbonitride MXene film according to claim 2, wherein the transition metal carbonitride 2D MXenes comprise at least one layer, each layer comprising a 2D array of crystalline cells having an empirical formula of M.sub.n+1X.sub.n, each X is positioned within an octahedral array of M, M is a transition metal selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, X is a solid solution of C and N, and n is 1, 2 or 3.
4. The heat-treated transition metal carbonitride MXene film according to claim 2, wherein the transition metal carbonitride 2D MXenes comprise at least one layer, each layer comprising a 2D array of crystalline cells having an empirical formula of M′.sub.2M″.sub.nX.sub.n+1, each X is positioned within an octahedral array of M′ and M″, M′ and M″ are different transition metals selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, X is a solid solution of C and N, and n is 1 or 2.
5. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein porosity of the MXene film is 2-90% (v/v).
6. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein surface electrical conductivity of the MXene film is 10-5,000 S/cm.
7. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein the MXene film exhibits electromagnetic interference (EMI) shielding effectiveness (SE) of 50-200 dB in a frequency range of 0.1-100 GHz.
8. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein a thickness of the MXene film is 0.1-5,000 μm.
9. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein the annealing is performed for 0.1-24 hours.
10. The heat-treated transition metal carbonitride MXene film according to claim 1, wherein the MXene film is for EMI shielding and electromagnetic absorption.
11. A polymer composite for electromagnetic interference (EMI) shielding and electromagnetic absorption, comprising the heat-treated transition metal carbonitride MXene film according to claim 1.
12. The polymer composite for EMI shielding and electromagnetic absorption according to claim 11, wherein the heat-treated transition metal carbonitride MXene film is sandwiched between polymers.
13. A method for producing the heat-treated transition metal carbonitride MXene film according to claim 1, the method comprising: obtaining a MXene aqueous solution containing dispersed 2-dimensional (2D) MXenes from MAX through an acid etching process; filtering the obtained MXene aqueous solution through a vacuum filtration process to produce a free-standing film; and annealing the produced free-standing film at a temperature of 100-500° C. for 0.1-24 hours to obtain a heat-treated transition metal carbonitride MXene film, wherein M is at least one transition metal selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, A is any one selected from Group 13 or 14 elements, and X represents carbon and nitrogen.
14. The method according to claim 13, wherein the annealing is performed under a continuous argon (Ar) flow condition.
15. An electromagnetic interference (EMI) shielding method, comprising: superposing a coating comprising the heat-treated transition metal carbonitride MXene film according to claim 1 on at least one surface of an object in a contact or non-contact manner.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0017] The present disclosure is described in more detail with reference to the accompanying drawings. Although exemplary embodiments for describing the present disclosure are shown in the drawings, the disclosed subject matter is not limited to the disclosure in the drawings. Additionally, the drawings are not necessarily drawn to scale.
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DETAILED DESCRIPTION
[0041] Ti.sub.3C.sub.2T.sub.x MXene, which is a typical 2-dimensional (2D) MXene material, has the highest electrical conductivity among MXenes, and accordingly, it has been expected that Ti.sub.3C.sub.2T.sub.x MXene would provide the best electromagnetic interference (EMI) shielding properties, but due to high electron density, Ti.sub.3C.sub.2T.sub.x MXene shows strong reflection of EMWs, and there was a risk of secondary damage caused by the strong reflection.
[0042] To solve the problem, the inventors developed MXene materials with improved electromagnetic absorption properties. The heat-treated transition metal carbonitride MXene film disclosed herein has improved absorption properties by changes of surface terminations through annealing and pore formation in the film, and consequential significant increase in EMI shielding effectiveness (SE).
[0043] Accordingly, the present disclosure relates to a transition metal carbonitride MXene film which is effective for EMI shielding and absorption and a method producing the same, and an EMI shielding method using the same.
[0044] In an aspect, the present disclosure may relate to a heat-treated transition metal carbonitride MXene film annealed at 100-500° C.
[0045] In an embodiment, the heat-treated transition metal carbonitride MXene film may be annealed at the temperature of 100° C. or more, 110° C. or more, 120° C. or more, 130° C. or more, 140° C. or more, 150° C. or more, 160° C. or more, 170° C. or more, 180° C. or more, 190° C. or more, 200° C. or more, 210° C. or more, 220° C. or more, 230° C. or more, 240° C. or more, 250° C. or more, 260° C. or more, 270° C. or more, 280° C. or more, 290° C. or more, 300° C. or more, 310° C. or more, 320° C. or more, 330° C. or more, 340° C. or more, 350° C. or more, 360° C. or more, 370° C. or more, 380° C. or more, 390° C. or more, 400° C. or more, 410° C. or more, 420° C. or more, 430° C. or more, 440° C. or more, 450° C. or more, 460° C. or more, 470° C. or more, 480° C. or more, or 490° C. or more, and the heat-treated transition metal carbonitride MXene film may be annealed at the temperature of 500° C. or less, 490° C. or less, 480° C. or less, 470° C. or less, 460° C. or less, 450° C. or less, 440° C. or less, 430° C. or less, 420° C. or less, 410° C. or less, 400° C. or less, 390° C. or less, 380° C. or less, 370° C. or less, 360° C. or less, 350° C. or less, 340° C. or less, 330° C. or less, 320° C. or less, 310° C. or less, 300° C. or less, 290° C. or less, 280° C. or less, 270° C. or less, 260° C. or less, 250° C. or less, 240° C. or less, 230° C. or less, 220° C. or less, 210° C. or less, 200° C. or less, 190° C. or less, 180° C. or less, 170° C. or less, or 160° C. or less.
[0046] In an embodiment, the MXene film may have a porous structure with laminated transition metal carbonitride 2D MXenes. That is, the MXene film may have a porous structure such that MXene layers of free-standing 2D assemblies with a continuous crystal structure are laminated and pores are formed between the MXene layers.
[0047] In an embodiment, the transition metal carbonitride 2D MXenes may comprise at least one layer, each layer comprising a 2D array of crystalline cells having an empirical formula of M.sub.n+1X.sub.n.
[0048] Here, each X may be positioned within an octahedral array of M, M may be a transition metal selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, X may be a solid solution of C and N, and n may be 1, 2 or 3.
[0049] In an embodiment, M may be, for example, Sc, Y, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W or a combination thereof, but is not limited thereto, and the empirical formula of M.sub.n+1X.sub.n may be, for example, Ti.sub.3CN and Ti.sub.2C.sub.0.5N.sub.0.5, but is not limited thereto.
[0050] In an embodiment, the transition metal carbonitride 2D MXenes may comprise at least one layer, each layer comprising a 2D array of crystalline cells having an empirical formula of M′.sub.2M″.sub.nX.sub.n+1.
[0051] Here, each X may be positioned within an octahedral array of M′ and M″, M′ and M″ may be different transition metals selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, X may be a solid solution C and N, and n may be 1 or 2.
[0052] In an embodiment, M may be, for example, Ti, V, Nb, Ta, Cr, Mo or a combination thereof, but is not limited thereto, and the empirical formula of M′.sub.2M″.sub.nX.sub.n+1 may be, for example, Ti.sub.2MoCN, but is not limited thereto.
[0053]
[0054] As shown in
[0055] In an embodiment, the porosity of the heat-treated transition metal carbonitride MXene film may be 2-90% (v/v). More specifically, the porosity of the heat-treated transition metal carbonitride MXene film may be 2% (v/v) or more, 4% (v/v) or more, 6% (v/v) or more, 8% (v/v) or more, 9% (v/v) or more, 10% (v/v) or more, 11% (v/v) or more, 12% (v/v) or more, 13% (v/v) or more, 14% (v/v) or more, 15% (v/v) or more, 16% (v/v) or more, 17% (v/v) or more, 18% (v/v) or more, 19% (v/v) or more, 20% (v/v) or more, 23% (v/v) or more, 25% (v/v) or more, 27% (v/v) or more, 30% (v/v) or more, 33% (v/v) or more, 35% (v/v) or more, 37% (v/v) or more, 40% (v/v) or more, 45% (v/v) or more, 50% (v/v) or more, 55% (v/v) or more, 60% (v/v) or more, 65% (v/v) or more, 70% (v/v) or more, 75% (v/v) or more, 80% (v/v) or more, or 85% (v/v) or more, and the porosity of the heat-treated transition metal carbonitride MXene film may be 90% (v/v) or less, 85% (v/v) or less, 80% (v/v) or less, 75% (v/v) or less, 70% (v/v) or less, 65% (v/v) or less, 60% (v/v) or less, 55% (v/v) or less, 50% (v/v) or less, 47% (v/v) or less, 45% (v/v) or less, 40% (v/v) or less, 37% (v/v) or less, 35% (v/v) or less, 33% (v/v) or less, 30% (v/v) or less, 27% (v/v) or less, 25% (v/v) or less, 23% (v/v) or less, 20% (v/v) or less, 19% (v/v) or less, 18% (v/v) or less, 17% (v/v) or less, 16% (v/v) or less, 15% (v/v) or less, 14% (v/v) or less, 13% (v/v) or less, 12% (v/v) or less, 11% (v/v) or less, 10% (v/v) or less, 9% (v/v) or less, 8% (v/v) or less, 6% (v/v) or less, or 4% (v/v) or less.
[0056] In an embodiment, the heat-treated transition metal carbonitride MXene film may have surface electrical conductivity of 10-5,000 S/cm. More specifically, the heat-treated transition metal carbonitride MXene film may have surface electrical conductivity of 10 S/cm or more, 50 S/cm or more, 100 S/cm or more, 200 S/cm or more, 300 S/cm or more, 400 S/cm or more, 500 S/cm or more, 600 S/cm or more, 700 S/cm or more, 800 S/cm or more, 900 S/cm or more, 1,000 S/cm or more, 1,050 S/cm or more, 1,100 S/cm or more, 1,120 S/cm or more, 1,125 S/cm or more, 1,150 S/cm or more, 1,200 S/cm or more, 1,300 S/cm or more, 1,400 S/cm or more, 1,500 S/cm or more, 1,600 S/cm or more, 1,700 S/cm or more, 1,800 S/cm or more, 1,900 S/cm or more, 2,000 S/cm or more, 2,100 S/cm or more, 2,200 S/cm or more, 2,300 S/cm or more, 2,400 S/cm or more, 2,450 S/cm or more, 2,500 S/cm or more, 2600 S/cm or more, 2,800 S/cm or more, 3,000 S/cm or more, 3,200 S/cm or more, 3,400 S/cm or more, 3,600 S/cm or more, 3,800 S/cm or more, 4,000 S/cm or more, 4,200 S/cm or more, 4,400 S/cm or more, 4,600 S/cm or more, or 4,800 S/cm or more, and the heat-treated transition metal carbonitride MXene film may have surface electrical conductivity of 5,000 S/cm or less, 4,800 S/cm or less, 4,600 S/cm or less, 4,400 S/cm or less, 4,200 S/cm or less, 4,000 S/cm or less, 3,800 S/cm or less, 3,600 S/cm or less, 3,400 S/cm or less, 3,200 S/cm or less, 3,000 S/cm or less, 2,800 S/cm or less, 2,600 S/cm or less, 2,490 S/cm or less, 2,480 S/cm or less, 2,475 S/cm or less, 2,400 S/cm or less, 2,300 S/cm or less, 2,200 S/cm or less, 2,100 S/cm or less, 2,000 S/cm or less, 1,900 S/cm or less, 1,800 S/cm or less, 1,700 S/cm or less, 1,600 S/cm or less, 1,500 S/cm or less, 1,400 S/cm or less, 1,300 S/cm or less, 1,200 S/cm or less, 1,100 S/cm or less, 1,000 S/cm or less, 900 S/cm or less, 800 S/cm or less, 700 S/cm or less, 600 S/cm or less, 500 S/cm or less, 400 S/cm or less, 300 S/cm or less, 200 S/cm or less, 100 S/cm or less, or 50 S/cm or less.
[0057] In an embodiment, the heat-treated transition metal carbonitride MXene film may exhibit EMI SE of 50-200 dB in the frequency range of 0.1-100 GHz. More specifically, the heat-treated transition metal carbonitride MXene film may exhibit EMI SE of 50 dB or more, 55 dB or more, 60 dB or more, 70 dB or more, 80 dB or more, 90 dB or more, 100 dB or more, 110 dB or more, 120 dB or more, 130 dB or more, 140 dB or more, 150 dB or more, 160 dB or more, 170 dB or more, 180 dB or more, or 190 dB or more in the frequency range of 0.1 GHz or more, 0.3 GHz or more, 0.5 GHz or more, 1 GHz or more, 2 GHz or more, 3 GHz or more, 5 GHz or more, 8 GHz or more, 9 GHz or more, 10 GHz or more, 11 GHz or more, 12 GHz or more, 15 GHz or more, 20 GHz or more, 30 GHz or more, 40 GHz or more, 50 GHz or more, 60 GHz or more, 70 GHz or more, 80 GHz or more, or 90 GHz or more, and 100 GHz or less, 90 GHz or less, 80 GHz or less, 70 GHz or less, 60 GHz or less, 50 GHz or less, 40 GHz or less, 30 GHz or less, 20 GHz or less, 15 GHz or less, 13 GHz or less, 12 GHz or less, 11 GHz or less, 10 GHz or less, 9 GHz or less, 8 GHz or less, 5 GHz or less, 3 GHz or less, 2 GHz or less, 1 GHz or less, 0.5 GHz or less, or 0.3 GHz or less, and the heat-treated transition metal carbonitride MXene film may exhibit EMI SE of 200 dB or less, 190 dB or less, 180 dB or less, 170 dB or less, 160 dB or less, 150 dB or less, 140 dB or less, 130 dB or less, 120 dB or less, 110 dB or less, 100 dB or less, 90 dB or less, 80 dB or less, 70 dB or less, 65 dB or less, 60 dB or less, or 55 dB or less in the above-described frequency range.
[0058] In an embodiment, the heat-treated transition metal carbonitride MXene film may be 0.1-5,000 μm in thickness. More specifically, the thickness of the heat-treated transition metal carbonitride MXene film may be 0.1 μm or more, 0.3 μm or more, 0.5 μm or more, 0.7 μm or more, 1 μm or more, 1.5 μm or more, 2 μm or more, 2.5 μm or more, 3 μm or more, 3.5 μm or more, 4 μm or more, 4.5 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, 70 μm or more, 100 μm or more, 200 μm or more, 300 μm or more, 400 μm or more, 500 μm or more, 600 μm or more, 700 μm or more, 800 μm or more, 900 μm or more, 1,000 μm or more, 1,500 μm or more, 2,000 μm or more, 2,500 μm or more, 3,000 μm or more, 3,500 μm or more, 4,000 μm or more, or 4,500 μm or more, and the thickness of the heat-treated transition metal carbonitride MXene film may be 5,000 μm or less, 4,500 μm or less, 4,000 μm or less, 3,500 μm or less, 3,000 μm or less, 2,500 μm or less, 2,000 μm or less, 1,500 μm or less, 1,000 μm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 70 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, 2.5 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, 0.7 μm or less, 0.5 μm or less, or 0.3 μm or less.
[0059] In an embodiment, the annealing may be performed for 0.1-24 hours. More specifically, the heat-treated transition metal carbonitride MXene film may be produced by annealing the transition metal carbonitride MXene film for 0.1 hours or more, 0.5 hours or more, 1 hour or more, 2 hours or more, 3 hours or more, 4 hours or more, 5 hours or more, 6 hours or more, 7 hours or more, 8 hours or more, 10 hours or more, 12 hours or more, 14 hours or more, 16 hours or more, 18 hours or more, 20 hours or more, or 22 hours or more, and the heat-treated transition metal carbonitride MXene film may be produced by annealing the transition metal carbonitride MXene film for 24 hours or less, 22 hours or less, 20 hours or less, 18 hours or less, 16 hours or less, 14 hours or less, 12 hours or less, 10 hours or less, 8 hours or less, 7 hours or less, 6 hours or less, 5 hours or less, 4 hours or less, 3 hours or less, 2 hours or less, or 1 hour or less.
[0060] In an embodiment, the heat-treated transition metal carbonitride MXene film may be for EMI shielding and electromagnetic absorption.
[0061] In another aspect, the present disclosure may relate to a polymer composite for EMI shielding and electromagnetic absorption, comprising the heat-treated transition metal carbonitride MXene film.
[0062] In an embodiment, the polymer composite may comprise the heat-treated transition metal carbonitride MXene film sandwiched between polymers.
[0063] In an embodiment, the heat-treated transition metal carbonitride MXene film may form a composite with polymer, and the polymer may include organic polymer, to be more specific, thermosetting or thermoplastic polymer or polymer resin, elastomer or a mixture thereof. The polymer may include, for example, polyester, polyethylenenaphthalate (PEN), polybutylene terephthalate (PBT), polyethersulfone (PES), polytetrafluoroethylene (PTFE), polyvinylfluoride (PVF), epoxy resin, polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polyetherimide (PEI), acrylate-based resin, polyamide (PA), acrylonitrile-butadiene-styrene (ABS) resin, polyamide imide (PAI), polybenzoimidazol (PBI), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), polyoxymethylene (POM), polyetherketone (PEK), polyetheretherketone (PEEK), polyaryletherketone (PAEK), liquid crystal polymer (LCP), polyimide (PI), polycarbonate (PC), sulfonated polyphenylene (SPR), (meth)acrylate-based polymer, urethane(meth)acrylate-based polymer, polystyrene (PS), polyurethane and polysiloxane, but is not limited thereto.
[0064] In another aspect, the present disclosure a method for producing the heat-treated transition metal carbonitride MXene film, comprising: obtaining a MXene aqueous solution containing dispersed 2D MXenes from MAX through an acid etching process; filtering the obtained MXene aqueous solution through a vacuum filtration process to produce a free-standing film; and annealing the produced free-standing film at the temperature of 100-500° C. for 0.1-24 hours to obtain a heat-treated transition metal carbonitride MXene film.
[0065] Here, M is at least one transition metal selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, A is any one selected from Group 13 or 14 elements, X represents carbon and nitrogen, and each of M, A and X is the same as described in detail above.
[0066] In an embodiment, an etchant used in the acid etching process may include strong acids containing F such as HF, NH.sub.4HF.sub.2 or HCl—LiF mixture, but is not limited thereto. The MXene produced by the acid etching process may be indicated by M.sub.n+1X.sub.n(T.sub.x) or M′.sub.2M″.sub.nX.sub.n+1(T.sub.x), where T.sub.x denotes terminations formed on the surface of the 2D MXene via etching as described in detail above, and may be, for example, —OH, ═O, —F or a combination thereof.
[0067] Additionally, the MXene aqueous solution prepared by the acid etching process may be an acidic solution with a pH of 1-6, a neutral solution with a pH of 6-7, and a basic solution with a pH of 8-14 by adjusting its pH.
[0068] In an embodiment, the annealing may be performed under continuous argon (Ar) flow conditions.
[0069] The annealing temperature and time in the annealing step is the same as described in detail above.
[0070] In another aspect, the present disclosure may relate to an EMI shielding method comprising: superposing a coating comprising the heat-treated transition metal carbonitride MXene film on at least one surface of an object in a contact or non-contact manner.
[0071] That is, the present disclosure may relate to a method for shielding an object from EMI by superposing a coating comprising the heat-treated transition metal carbonitride MXene film according to an aspect of the present disclosure on at least one surface of the object in a contact or non-contact manner.
[0072] As an embodiment, the present disclosure may provide the following embodiments, and the following embodiments are provided to supplement the previous description, but not intended to replace or substitute the previous description.
[0073] A first embodiment may provide a heat-treated transition metal carbonitride MXene film annealed at 100-500° C.
[0074] A second embodiment may provide the heat-treated transition metal carbonitride MXene film according to the first embodiment, wherein the MXene film has a porous structure with laminated transition metal carbonitride 2D MXenes.
[0075] A third embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first and second embodiments, wherein the transition metal carbonitride 2D MXenes comprise at least one layer, each layer comprising a 2D array of crystalline cells having an empirical formula of M.sub.n+1X.sub.n, each X is positioned within an octahedral array of M, M is a transition metal selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, X is a solid solution of C and N, and n is 1, 2 or 3.
[0076] A fourth embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to third embodiments, wherein the transition metal carbonitride 2D MXenes comprise at least one layer, each layer comprising a 2D array of crystalline cells having an empirical formula of M′.sub.2M″.sub.nX.sub.n+1, each X is positioned within an octahedral array of M′ and M″, M′ and M″ are different transition metals selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, X is a solid solution of C and N, and n is 1 or 2.
[0077] A fifth embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to fourth embodiments, wherein porosity of the MXene film is 2-90% (v/v).
[0078] A sixth embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to fifth embodiments, wherein surface electrical conductivity of the MXene film is 10-5,000 S/cm.
[0079] A seventh embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to sixth embodiments, wherein the heat-treated transition metal carbonitride MXene film exhibits EMI SE of 50-200 dB in a frequency range of 0.1-100 GHz.
[0080] An eighth embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to seventh embodiment, wherein a thickness of the MXene film is 0.1-5,000 μm.
[0081] A ninth embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to eighth embodiments, wherein the annealing is performed for 0.1-24 hours.
[0082] A tenth embodiment may provide the heat-treated transition metal carbonitride MXene film according to at least one of the first to ninth embodiments, wherein the MXene film is for EMI shielding and electromagnetic absorption.
[0083] An eleventh embodiment may provide a polymer composite for EMI shielding and electromagnetic absorption, comprising the heat-treated transition metal carbonitride MXene film according to any one of the first to tenth embodiments.
[0084] A twelfth embodiment may provide the polymer composite for EMI shielding and electromagnetic absorption according to the eleventh embodiment, wherein the heat-treated transition metal carbonitride MXene film is sandwiched between polymers.
[0085] A thirteenth embodiment may provide a method for producing the heat-treated transition metal carbonitride MXene film according to any one of the first to tenth embodiments, comprising: obtaining a MXene aqueous solution containing dispersed 2D MXenes through an acid etching process; filtering the obtained MXene aqueous solution through a vacuum filtration process to produce a free-standing film; and annealing the produced free-standing film at the temperature of 100-500° C. for 0.1-24 hours to obtain a heat-treated transition metal carbonitride MXene film, where M is at least one transition metal selected from the group consisting of Group IIIB metal, Group IVB metal, Group VB metal and Group VIB metal, A is any one selected from Group 13 or 14 elements, and X denotes carbon and nitrogen.
[0086] A fourteenth embodiment may provide the method according to the thirteenth embodiment, wherein the annealing is performed under a continuous argon (Ar) flow condition.
[0087] A fifteenth embodiment may provide an EMI shielding method comprising: superposing a coating comprising the heat-treated transition metal carbonitride MXene film according to any one of the first to tenth embodiments on at least one surface of an object in a contact or non-contact manner.
[0088] The transition metal carbonitride MXene according to an aspect of the present disclosure is a solid solution MXene in which half of carbon atoms occupying octahedral sites in AB-AB hexagonal structure are substituted by nitrogen atoms, and due to the change in chemical composition, the transition metal carbonitride MXene has unique properties that are very different from the counterpart transition metal carbide MXene, i.e., having the same transition metal.
[0089] Specifically, the transition metal carbonitride MXene film, according to an aspect of the present disclosure, exhibits a larger interlayer spacing (d-spacing). The large d-spacing of transition metal carbonitride MXene is due to its high tendency to absorb water molecules, and this may be the cause of its low electrical conductivity at room temperature. The following examples confirmed that when the transition metal carbonitride MXene film according to an aspect of the present disclosure is annealed, as the annealing temperature increases, the desorption of water molecules increases and the surface terminations of each layer are removed, and thus the d-spacing value decreases and the electrical conductivity increases.
[0090] The removal of water molecules and surface terminations gives rise to porosity in transition metal carbonitride MXene film, and this shows a direct relationship with the annealing temperature. It is expected that the induced porosity will improve the total EMI shielding and electromagnetic absorption in the porous structure of transition metal carbonitride MXene film, and the porous structure has a positive influence on EMI shielding by extending the path length of EMWs before transmission and improving the subsequent absorption phenomenon with the introduction of multiple interfaces acting as scattering sites for the incident EMWs.
[0091] Additionally, according to theoretical studies, as the porosity is higher, EMI shielding properties are enhanced and absorption contribution is improved. This factor may be enhanced when high porosity does not reduce the electrical conductivity of shielding materials. The following examples confirmed that in the case of the transition metal carbonitride MXene film according to an aspect of the present disclosure, the porosity linearly increases with the increasing annealing temperature, but as the temperature increases, the film becomes unstable for oxidation, and transition metal oxide nanocrystals which are dielectrics are formed on the surface of the film, resulting in low electrical conductivity, and severe oxidation causes degradation of the electrical properties of the film and degradation of the overall EMI shielding properties.
[0092] However, the following examples confirmed that as a result of analyzing the EMI shielding properties of transition metal carbide MXene film annealed in the same condition, as opposed to transition metal carbonitride MXene film, it is stable for oxidation, has a small d-spacing value and high electrical conductivity, and undergoes less volume expansion arising from porosity due to annealing, but rather results in lower final EMI shielding properties.
EXAMPLES
[0093] Hereinafter, the following examples are provided to describe the present disclosure in more detail. Each example is regarded as providing each specific embodiment of compositions and fabrication and use methods, but none of the examples should be deemed as limiting the more generic embodiments described herein. In particular, the following examples focus specific 2-dimensional (2D) titanium carbonitride Ti.sub.3CNT.sub.x MXenes and their fabrication methods and their electromagnetic shielding effectiveness, but the described principle may be applied to other 2D transition metal carbonitride MXenes. That is, these examples are provided to help the understanding of the present disclosure and should not be interpreted as limiting the present disclosure, and modifications, substitutions and addition commonly known in the art may be made thereto, and the scope of the present disclosure covers such modifications, substitutions and addition.
[0094] In the following examples, attempts have been made to ensure accuracy of the used names and figures (for example, composition, amount, temperature, thickness, etc.), but some experimental errors and deviations should be considered, and unless otherwise stated, the temperature is in degree Celsius (° C.) and the pressure is at or near atmospheric.
Example 1. Materials and Methods
Example 1.1 Materials
[0095] Ti.sub.3AlCN MAX powder with a particle size of less than 38 μm was synthesized at the lab scale following Hantanasirisakul, K., et al., Effects of Synthesis and Processing on Optoelectronic Properties of Titanium Carbonitride MXene. Chemistry of Materials, 2019. 31: p. 2941-2951, and Ti.sub.3AlC.sub.2 MAX powder with a particle size of less than 38 μm was purchased from Carbon-Ukraine ltd. Lithium fluoride (LiF, 98.5%) and hydrochloric acid (HCl, 37%) were purchased from Alfa Aesar, and polypropylene membrane (Celgard, pore size 0.064 μm) was used to obtain MXene films via vacuum-assisted filtration.
Example 1.2 Synthesis of Ti.SUB.3.CNT.SUB.x .MXene
[0096] Ti.sub.3CNT.sub.x was synthesized from Ti.sub.3AlCN MAX phase. In this synthesis protocol, Ti.sub.3AlCN was used instead of Ti.sub.3AlC.sub.2. Briefly describing, 1 g of Ti.sub.3AlCN MAX was gradually added to a mixture of 20 mL of 9 M HCl and 1.6 g of LiF in a 100 mL polypropylene bottle with continuous stirring at room temperature for 24 hours. The obtained mixture was washed with deionized water 5-6 times by centrifugation at 3500 rpm to reach close to a neutral pH value. Finally, a stable well-dispersed suspension containing single-to-few layer Ti.sub.3CNT.sub.x MXene flakes was obtained by collecting the supernatant after centrifugation at 3500 rpm for 5 minutes.
Example 1.3 Preparation of Ti.SUB.3.CNT.SUB.x .MXene Film
[0097] Free-standing films were prepared by filtering a measured amount of MXene dispersion through a Celgard membrane. The thickness of the films was controlled by the volume of the as-synthesized dispersion during vacuum filtration.
Example 1.4 Annealing of Ti.SUB.3.CNT.SUB.x .MXene Film
[0098] The films with different thicknesses were thermally treated in an inert environment of continuous argon (Ar) flow at different annealing temperatures of 150° C., 250° C. and 350° C. for 6 hours. Additionally, 40 μm-thick Ti.sub.3CNT.sub.x MXene films were annealed at 350° C. for different annealing times of 0.5, 1, 2, 3, 6, 12 and 24 hours.
Example 1.5 Synthesis of Ti.SUB.3.C.SUB.2.T.SUB.x .MXene
[0099] Ti.sub.3C.sub.2T.sub.x was synthesized from Ti.sub.3AlC.sub.2 MAX powder after etching “Al” layers. The synthesis method of Ti.sub.3C.sub.2T.sub.x is the same as described in U.S. patent application Ser. No. 16/092,338 filed on Apr. 21, 2017, and all the conditions were the same as those reported above for Ti.sub.3CNT.sub.x except the synthesis temperature. In this case, the synthesis temperature was increased up to 35° C. to get a higher yield from the reaction. The obtained films (similar in thickness to Ti.sub.3CNT.sub.x film) after vacuum filtration of the solution were annealed at the same temperature as Ti.sub.3CNT.sub.x.
Example 1.6 Annealing of Spray-Coated MXene Films on a Glass Substrate
[0100] Micrometer-thick Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXene films were spray-coated on a glass substrate and completely dried on a hot plate set to the temperature of 90° C. The spray-coated films were annealed to analyze the adhesive strength of the MXene films during heat treatment. In this instance, the spray-coated Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXene films on the glass substrate were annealed at 350° C. for 6 hours.
Example 2 Materials Characterization
Example 2.1 Characterization
[0101] The structure and morphology of pristine and heat-treated Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXene films were investigated by a scanning electron microscope (SEM) (Inspect F50, FEI, USA) and a transmission electron microscope (TEM) (Tecnai F20 G2, FEI, at 200.0 kV voltage). The initial thickness measurements were performed using a highly accurate length gauge (with a tolerance factor of ±0.1 μm) of Heidenhain Instruments (Germany), and were verified using SEM.
[0102] A focused ion beam (FIB) (Nova 600 Nanolab, FEI Company, Netherland) was used to cut the cross-section of the films in order to analyze the cross-sectional morphology of the samples using high resolution TEM images and element mapping (high resolution TEM (HRTEM) Talos, FEI Company, F200X).
[0103] X-ray diffraction (XRD) patterns were obtained using a D8 diffractometer with Cu-Kα radiation (40 kV and 44 mA) at a 28 (theta) range of 4° to 70° with a scanning step of 0.02°, a step time of 0.5 s, and a window slit of 10×10 mm.sup.2. Changes in chemical structure were examined using X-ray photoelectron spectroscopy (XPS, PHI 5000 VersaProbe, Ulvac-PHI, Japan) by Al-Kα as the X-ray source with a power of 25 W.
[0104] Simultaneous thermogravimetric-mass spectrometry analysis (TGA-MS) was performed on a Discovery SDT 650 model connected to a Discovery mass spectrometer (TA Instruments, DE). Vacuum-filtered films of MXenes were cut into small pieces and packed in a 90 μL alumina pan. Before heating, the analysis chamber was flushed with helium (He) gas at 100 mL/min for 1 hour to reduce residual air. The samples were heated to 350° C. at a constant heating rate of 10° C./min in the He atmosphere (100 mL/min).
[0105] The density and porosity were calculated experimentally using the mass and volume of the films.
[0106] Electrical conductivity of the samples was measured using an advanced four probe (MCP-TP06P PSP) connected with Loresta-GP meter (Model MCP-T610, Mitsubishi Chemical, Japan). The distance between pins of the probe was 1.5 mm, and the open circuit voltage was set to 10 V. The 4-pin probe was positioned at different locations of the film (a minimum of 5 locations to obtain an average value) and the sheet resistance was recorded. Subsequently, the electrical conductivity of all the samples was calculated by σ=(R.sub.s×t).sup.−1, where σ is the electrical conductivity [S/cm], R.sub.s is the sheet resistance [Ω/sq], and t is the thickness [cm] of the sample.
[0107] Electromagnetic interference (EMI) shielding effectiveness (SE) of all the samples was measured by WR-90 rectangular waveguide using a 2-port network analyzer (ENA5071C, Agilent Technologies, USA) in the frequency range of 8.2-12.4 GHz (X-band). The standard calibration procedure for equipment calibration was performed using short offset, short and load on both ports. The pristine and annealed samples were cut into rectangular dimensions of 25×12 mm.sup.2, slightly larger than that of sample holder's opening 22.84×10.14 mm.sup.2. The samples were mounted carefully to avoid any leakage from the edges of the waveguide and screwed tightly before taking the final measurements.
Example 2.2 EMI Shielding Effectiveness Measurements
[0108] EMI SE is the ability of a material to attenuate the energy of incident EMWs. When electromagnetic radiations interact with the material under test (shield), the shielding phenomenon is governed by reflection (R), absorption (A) and transmission (T), collectively must add up to 1. That is, the following equation is given:
R+T+A=1 (1)
[0109] The reflection (R) and transmission (T) coefficients are obtained from the network analyzer in the form of scattering parameters (S.sub.12, S.sub.12, S.sub.21, S.sub.22), which can be used to find the R and T coefficients as:
R=|S.sub.11|.sup.2=|S.sub.22|.sup.2 (2)
T=|S.sub.21|.sup.2=|S.sub.12|.sup.2 (3)
[0110] The total EMI SE (EMI SE.sub.T) is the sum of the contributions from reflection (SE.sub.R), absorption (SE.sub.A) and multiple internal reflections (SE.sub.MR). The total EMI SE.sub.T can be written as:
SE.sub.T=SE.sub.R+SE.sub.A+SE.sub.MR (4)
[0111] For calculations, SE.sub.MR is generally considered negligible when SE.sub.T is higher than 15 dB. SE.sub.R and SE.sub.A can be expressed in terms of reflection and absorption coefficient considering the power of the incident EMWs inside the shielding material as:
[0112] Assuming propagation of EMWs in a nonmagnetic and highly conducting medium, the Fresnel formula for reflection, absorption and multiple reflections, using equation 4, can be given as:
[0113] where E.sub.i and E.sub.t are incident and transmitted intensities of electric field of the EMWs, respectively; N is the complex refractive index of the shield, k is the imaginary part of refractive index, and d is the shield thickness. Due to its excellent conductivity (5,000-10,000 S/cm), the complex refractive index (Nm) of MXene is given as:
[0114] In equation 7, the quantitative contributions from SE.sub.R, SE.sub.A and SE.sub.MR are expressed as:
[0115] In equation 9, α is the attenuation constant indicating the ability of a material to absorb the associated energy of incident EMWs. Neglecting the role of multiple reflection for total shielding efficiency SE.sub.T higher than 15 dB, using equations 4, 8 and 9, SE.sub.T can be written as the following equation known as Simon's formula:
Example 2.3 Theoretical Calculation of EMI Shielding Effectiveness (SE)
[0116] Theoretical EMI SE.sub.T, SE.sub.E, and SE.sub.A for Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXenes were calculated by transfer matrix method. The transfer matrix method considers analytical solution for calculating transmission, reflection, and absorption of EMWs propagating through a 2D infinite plane interface and layers with known thickness.
[0117] This method provides an exact solution for multiple reflections between layers having much smaller thickness than the wavelength of incident waves. The transfer equation for the propagation through N thin layers is expressed as follows:
[0118] where M1 and M2 are the transfer matrices for the propagation through an interface and propagation within a layer, respectively. E.sup.+ and E.sup.− represent the electric field amplitudes of the forward and backward EMWs in a medium, respectively.
[0119] In homogeneous and isotropic media, the matrices M1 and M2 are expressed as:
[0120] Here, r.sub.ij and t.sub.ij are the complex amplitude reflection and transmission Fresnel coefficients, respectively, and EMWs propagate from the i layer to the j layer through the interfaces. ϕ is represented as
where n and I are the complex refractive index and the thickness, respectively, and A is the wavelength of the EMWs propagating in free space.
[0121] From equation 12, the reflection and transmission coefficients are calculated as below:
[0122] Therefore, using equation 14, SE.sub.T, SE.sub.R and SE.sub.A can be expressed as below:
Example 3 Analysis Results
Example 3.1 Structural Characterization of MAX and MXene
[0123] As in the above example 1, Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXenes were synthesized by chemical etching of the Al atoms from their parent MAX phases, Ti.sub.3AlCN and Ti.sub.3AlC.sub.2, respectively, and XRD patterns of the parent MAX phases and the corresponding MXenes are shown in
Example 3.2 Fabrication of Free-Standing Ti.SUB.3.CNT.SUB.x .and Ti.SUB.3.C.SUB.2.T.SUB.x .MXene Films, Annealing the Same, and Structural Characterization of the Same
[0124] Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x free-standing films of different thickness were fabricated via vacuum-assisted filtration of aqueous suspensions of Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXenes, respectively, followed by annealing at different temperatures of 150° C., 250° C. and 350° C. for 6 hours under an argon atmosphere. Structural changes in Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x MXene films under thermal annealing were analyzed by XRD as shown in
Example 3.3 Thermogravimetric Analysis of Ti.SUB.3.CNT.SUB.x .and Ti.SUB.3.C.SUB.2.T.SUB.x .MXene Film
[0125]
Example 3.4 Structural Analysis of Annealed Ti.SUB.3.CNT.SUB.x .and Ti.SUB.3.C.SUB.2.T.SUB.x .MXene Film
[0126] X-ray photoelectron spectroscopy (XPS) survey spectra before thermal annealing (
[0127]
Example 3.5 Cross-Sectional Morphology of Annealed Ti.SUB.3.CNT.SUB.x .and Ti.SUB.3.C.SUB.2.T.SUB.x .MXene Film
[0128] Cross-sectional high-resolution TEM (HRTEM) images show structural changes in 40-μm-thick Ti.sub.3CNT.sub.x film as a function of annealing temperature (
[0129] As shown in
[0130] The porosity also depends on the initial thickness of the films annealed at fixed temperature of 350° C. as shown in
Example 3.6 Electrical Conductivity of Annealed Ti.SUB.3.CNT.SUB.x .and Ti.SUB.3.C.SUB.2.T.SUB.x .MXene Film
[0131]
[0132] On the contrary, Ti.sub.3C.sub.2T.sub.x films showed a monotonous increment in electrical conductivity from 4500 to 5225 S/cm with increasing annealing temperature, indicating that Ti.sub.3C.sub.2T.sub.x films are more stable and develop less porosity as compared to Ti.sub.3CNT.sub.x films.
Example 3.7 EMI Shielding of Annealed Ti.SUB.3.CNT.SUB.x .and Ti.SUB.3.C.SUB.2.T.SUB.x .MXene Film
[0133]
[0134]
[0135] It can be seen from
[0136] The thickness dependences at the annealing temperature of 350° C. are shown in
Example 3.8 Influence of Annealing Time on Ti.SUB.3.CNT.SUB.x .MXene Film
[0137]
Example 3.9 EMI Shielding Mechanism of Ti.SUB.3.CNT.SUB.x .MXene Film
[0138] The dramatic increase in SE.sub.A as shown in
[0139] The Ti.sub.3CNT.sub.x film annealed at 350° C. has much larger EMI SE.sub.A and SE.sub.T than the Ti.sub.3CNT.sub.x film annealed at 250° C. despite its lower electrical conductivity. Moreover, the Ti.sub.3CNT.sub.x film annealed at 350° C. has much larger EMI SE.sub.A and SE.sub.T than the Ti.sub.3C.sub.2T.sub.x film annealed at the same temperature, which has a much larger electrical conductivity. These results suggest a possible role of the induced porous structure coupled with partial oxidation in enhancing the electromagnetic absorption shielding efficiency, but a quantum mechanical approach is required for interaction of EMWs with nanometer-thin 2D metals, like MXenes, where macroscopic theories cannot be used.
[0140] The experimental SE.sub.T, SE.sub.E, and SE.sub.A results for Ti.sub.3CNT.sub.x and Ti.sub.3C.sub.2T.sub.x laminate films are compared with the theoretical calculations by the transfer matrix method (for data consistency, see
[0141] The failure of theoretical prediction of the EMI shielding behavior of the annealed Ti.sub.3CNT.sub.x films indicates that in addition to electrical conductivity and induced porosity, dipolar polarizations and low order of magnitude of MXenes should be considered. In particular, extraordinarily large absorption of annealed Ti.sub.3CNT.sub.x films may be caused by the formation of similar structures to metamaterials from atomically thin MXene sheets after annealing. When loss components of effective dielectric constant and electromagnetic permeability of metamaterials increase, the absorption of electromagnetic radiation is improved. Accordingly, further studies are needed to understand the particular shielding mechanism of Ti.sub.3CNT.sub.x responsible for experimentally observed large absorption ability of the annealed Ti.sub.3CNT.sub.x samples.
[0142] The comparison results of EMI SE.sub.T of Ti.sub.3CNT.sub.x films with the values reported in previous studies are shown in
TABLE-US-00001 TABLE 1 Filler Thickness EMI SE Type Filler [wt. %] Matrix [cm] [dB] Ref Graphene and graphite Graphene Bulk / 0.005 60 1 Graphene Bulk / 8.40 × 10.sup.−4 20 2 Graphene(annealed) Bulk / 0.006 90 3 Graphene/CNTs Bulk / 0.16 38 4 Graphene/CNTs Bulk / 0.16 36 5 rGO 7 PS 0.25 45.1 6 rGO 30 PS 0.25 29 7 rGO 25 PEDOT:PSS 0.08 70 8 rGO 3.07 PDMS 0.2 54.2 9 Graphene 0.8 PDMS 0.1 20 10 rGO/Fe3O4 10 PEI 0.25 18 11 rGO 10 PEI 0.23 12.8 12 rGO 16 PI 0.08 21 13 rGO 1 PU 0.25 23 14 rGO 3 Epoxy 0.1 38 15 rGO/Fe.sub.3O.sub.4 Bulk / 0.03 24 16 PEDOT:PSS 4.6 rGO 0.15 91.9 17 EG 98 HANF 0.006 60.4 18 90 0.006 47.4 Carbon (fibres/nanotubes) Carbon / Bulk 1 51 19 Carbon / PN resin 0.2 51.2 20 Carbon foam / Bulk 0.2 40 21 CB 15 ABS 0.11 20 22 SWCNT 30 MWCNT 0.013 65 23 SWCNT 15 Epoxy 0.1 20 24 SWCNT 7 PS 0.12 18.5 25 MWCNT 25 MCMB 0.06 56 26 MWCNT 15 ABS 0.11 50 22 MWCNT 20 PC 0.21 39 27 MWCNT 20 PS 0.2 30 28 MWCNT 76.2 WPU 0.1 21.1 29 CNT 20 rGO 0.0015 57.6 30 CNT sponge 1 PDMS 0.18 54.8 31 Metals Al Foil Bulk / 0.80 × 10.sup.−3 66 32 Cu Foil 0.001 70 CuNi Bulk / 0.15 25 33 CuNi-CNT 0.15 54.6 Copper Bulk / 0.31 90 34 Cu coated beads / PCL 0.2 110 35 Ni filament 7 PES 0.285 86.6 36 Ag nanowire 67 Carbon 0.3 70.1 37 Ag nanowire 28.6 WPU 0.23 64 38 Ag nanowire 4.5 PI 0.5 35 39 Ag nanowire 4.5 PI 0.5 35 1 Ag nanofiber / Bulk 0.01 76 40 0.10 × 10.sup.−3 20 SS Bulk / 0.4 89 36 SS 1.1 PP 0.31 48 34 Others Carbon Foam Bulk / 0.2 51.2 41 Carbon Foam Bulk / 0.2 40 21 Flexible graphite Bulk / 0.31 130 42 0.079 102 MoS.sub.2 30 Glass 0.15 24.2 43 rGO/y-Fe.sub.2O.sub.3 75 PANI 0.25 51 44 rGO/Fe.sub.3O.sub.4 66 PANI 0.25 30 45 rGO/Fe.sub.3O.sub.4 Bulk / 0.025 24 16 rGO/CNT/Fe.sub.3O.sub.4 Bulk / 0.2 37.5 46 rGO-BaTiO.sub.3 Bulk / 0.15 41.7 47 MXenes (literature data) Ti.sub.3C.sub.2T.sub.x film Bulk / 0.15 × 10.sup.−3 48 32 0.25 × 10.sup.−3 54 0.60 × 10.sup.−3 59 1.12 × 10.sup.−3 68 2.15 × 10.sup.−3 78 4.0 × 10.sup.−3 87 4.50 × 10.sup.−3 92 Ti.sub.3C.sub.2T.sub.x film 90 SA 0.80 × 10.sup.−3 57 32 Mo.sub.2Ti.sub.2C.sub.3T.sub.x film Bulk / 0.25 × 10.sup.−3 26 32 Mo.sub.2TiC.sub.2T.sub.x film 0.25 × 10.sup.−3 23 MXene foam Bulk / 6.00 × 10.sup.−3 70 48 1.80 × 10.sup.−3 50 0.60 × 10.sup.−3 32 Ti.sub.3C.sub.2T.sub.x 50 cellulose 16.7 × 10.sup.−3 25 49 80 7.40 × 10.sup.−3 26 90 4.70 × 10.sup.−3 24 TiO.sub.2-Ti.sub.3C.sub.2/graphene / / 9.17 × 10.sup.−4 27 50 7.82 × 10.sup.−4 23.4 5.59 × 10.sup.−4 23.3 5.25 × 10.sup.−4 18 Ti.sub.3C.sub.2/SWONT / PVA/PSS 2.07 × 10.sup.−5 3.39 51 Ti.sub.3C.sub.2/MWCNT 1.70 × 10.sup.−5 2.81 Ti.sub.3C.sub.2T.sub.x aerogel Bulk 0.10 44.8 52 Ti.sub.2CT.sub.x aerogel / 0.10 48.5 Ti.sub.3CNT.sub.x aerogel 0.10 42.3 Ti.sub.2CT.sub.x Bulk / 1.1 × 10.sup.−3 50 53 V.sub.2CT.sub.x / 1.2 × 10.sup.−3 46 Nb.sub.2CT.sub.x / 1.0 × 10.sup.−3 15 Ti.sub.yNb.sub.2-yCT.sub.x / 1.4 × 10.sup.−3 50 Nb.sub.yV.sub.2-yCT.sub.x / 1.2 × 10.sup.−3 36 Ti.sub.3C.sub.2T.sub.x / 1.4 × 10.sup.−3 70 Ti.sub.3CNT.sub.x / 1.0 × 10.sup.−3 55 Mo.sub.2TiC.sub.2T.sub.x / 1.0 × 10.sup.−3 21 Nb.sub.4C.sub.3T.sub.x / 1.1 × 10.sup.−3 26 Mo.sub.2Ti.sub.2C.sub.3T.sub.x / 1.3 × 10.sup.−3 37 Ti.sub.3C.sub.2T.sub.x ultrathin film / 5.5 × 10.sup.−6 20 54 nes (this work *Pristine Ti.sub.3CNT.sub.x Bulk / 0.001 43.5 This 0.002 47.9 study 0.003 53.3 0.004 61.4 *Heat-treated Bulk / 0.001 75.1 Ti.sub.3CNT.sub.x 0.002 83.0 0.003 97.1 0.004 116.2 *Pristine Ti.sub.3C.sub.2T.sub.x Bulk / 0.001 66.5 0.002 74.6 0.003 77.9 0.004 83.5 *Heat-treated Ti.sub.3C.sub.2T.sub.x Bulk / 0.001 74.1 0.002 81.1 0.003 85.2 0.004 93.0 *CNT: carbon nanotube; rGO: reduced graphene oxide; EG: expanded graphite; CB: carbon black; SWCNT: single-wall carbon nanotube; MWCNT: multi-wall carbon nanotube; PS: polystyrene; PEDOT:PSS: poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate); PEI: polyethylenimine; PI: polyimide; PU: polyurethane; WPU: water-borne polyurethane; HANF: hydrated aramid nanofiber; MCMB: meso-carbon microbead; ABS: acrylonitrile-butadiene-styrene; PDMS; polydimethylsiloxane; PCL: poly(c-caprolactone); PES: polyethersulfone; PP: polypropylene; PANI: polyaniline; PN resin: phthalonitrile resin; PC: polycarbonate; PVA/PSS: poly(vinyl alcohol)/poly(sodium 4-styrene sulfonate); SS: stainless steel; SA: sodium alginate.
Example 3.10 Dimensional Stability of Ti.SUB.3.CNT.SUB.x .MXene Film
[0143]
[0144] It can be seen from