Flexible, Ultralight, and Mechanically Robust Waterborne Polyurethane/Ti3C2Tx MXene/Nickel Ferrite Hybrid Aerogels for High-Performance Electromagnetic Interference Shielding.
28 Apr 2021-ACS Applied Materials & Interfaces (American Chemical Society (ACS))-Vol. 13, Iss: 18, pp 21831-21843
TL;DR: In this paper, a novel waterborne polyurethane/Ti3C2Tx MXene/nickel ferrite (WPU/MXene/NiFe2O4) hybrid aerogel was constructed by constructing a strong chemical bonding interaction between an NCOterminated WPU prepolymer and hydroxyl functionalized MXene nanosheets.
Abstract: Flexible, ultralight, and mechanically robust electromagnetic interference (EMI) shielding materials are urgently demanded to manage the increasing electromagnetic radiation pollution, but it remains a great challenge to simultaneously achieve ultralight yet mechanically robust properties while retaining high-efficiency EMI shielding performance. Herein, we fabricate a novel waterborne polyurethane/Ti3C2Tx MXene/nickel ferrite (WPU/MXene/NiFe2O4) hybrid aerogel by constructing a strong chemical bonding interaction between an NCO-terminated WPU prepolymer and hydroxyl functionalized MXene nanosheets. The resultant aerogels exhibit remarkable lightweight and mechanical properties, particularly high compressive stress far exceeding that of other MXene-based and WPU-based porous materials. Furthermore, synergistic effects of the oriented porous architecture and the multiphase skeleton endow the hybrid aerogels with a high X-band EMI shielding effectiveness (SE) of 64.7 dB at a low density of ∼38.2 mg/cm3. The corresponding specific SE value achieves 1694-3124 dB·cm3/g, and the SSE/d is up to 15,620 dB·cm2/g, surpassing that of most reported EMI shielding materials. Importantly, this aerogel, with excellent electromagnetic radiation protection effects and shielding reliability, is highly promising for long-term and effective EMI shielding service in various application environments.
Citations
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TL;DR: In this article, the authors reviewed the milestones and the latest progress in the research of MAX phases and MXenes, from the perspective of ceramic science, focusing on the conversion from MAX phases to MXenes.
Abstract: MAX phases (Ti3SiC2, Ti3AlC2, V2AlC, Ti4AlN3, etc.) are layered ternary carbides/nitrides, which are generally processed and researched as structure ceramics. Selectively removing A layer from MAX phases, MXenes (Ti3C2, V2C, Mo2C, etc.) with two-dimensional (2D) structure can be prepared. The MXenes are electrically conductive and hydrophilic, which are promising as functional materials in many areas. This article reviews the milestones and the latest progress in the research of MAX phases and MXenes, from the perspective of ceramic science. Especially, this article focuses on the conversion from MAX phases to MXenes. First, we summarize the microstructure, preparation, properties, and applications of MAX phases. Among the various properties, the crack healing properties of MAX phase are highlighted. Thereafter, the critical issues on MXene research, including the preparation process, microstructure, MXene composites, and application of MXenes, are reviewed. Among the various applications, this review focuses on two selected applications: energy storage and electromagnetic interference shielding. Moreover, new research directions and future trends on MAX phases and MXenes are also discussed.
77 citations
TL;DR: In this article , a NiCo 2 O 4 nanosheets-covered Ti 3 C 2 T x MXene (NiCo 2 o 4 NSs-MXene) heterostructure with multi-layered MXene and vertically grown ultrathin NiCo O 4 Ns-NOMs prepared by detachment process, reflux reaction, and heat-treatment is introduced as a new EMW absorber, enabling a shocking EMW absorption performance of −72.3 dB at a thickness of 1.7 mm.
54 citations
TL;DR: In this paper, a flexible "brick-mortar" layered NiCo/MX-CNT composite film with high conductivity and strong attenuation capacity was proposed to enrich the wave loss mechanism.
Abstract: Highly conductive Ti3C2Tx MXene-based electromagnetic interference (EMI) shielding materials have shown great application potential in facing the increasingly serious electromagnetic radiation threat but are limited by their single-loss mechanism. Here, to enrich the wave loss mechanism, magnetic Ti3C2Tx MXene and conductive carbon nanotubes (CNTs) have been assembled into a flexible “brick-mortar” layered NiCo/MX–CNT film to simultaneously obtain high conductivity and strong attenuation capacity. Interestingly, by combining the strong attenuation ability of the magnetic NiCo/MX and high conductivity of CNTs, as well as the dense stacking “brick-mortar” layered structure, 99.99999991% (90.7 dB of EMI shielding effectiveness, SE) of the electromagnetic waves can be reflected and absorbed by the NiCo/MX–CNT composite film with only 53 μm thickness, which is one of the best shielding effects achieved and is superior to that of pure CNT film (∼71 dB) and pure MXene film (∼61 dB), even if they have higher conductivity. Moreover, the composite film can realize EMI shielding property modulation from 46 to 105 dB by adjusting the film thickness from 9 to 116 μm. The dense stacking “brick-mortar” layered structure endows the composite film with excellent flexibility, foldability, and robust mechanical properties, which significantly improve the practical potential in complex application environments.
49 citations
TL;DR: Recently, the quest for aerogel nanocomposites has escalated due to inherently unique and beneficial properties, which in addition to sol-gel chemistry have enlarged their scope of applications as discussed by the authors.
42 citations
TL;DR: In this article, a flexible water-borne polyurethane (WPU)/MXene aerogel was applied as a supporting scaffold to confine polyethylene glycol (PEG) to fabricate photo-driven and flexible phase change material (PCM) composites.
40 citations
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TL;DR: The mechanical flexibility and easy coating capability offered by MXenes and their composites enable them to shield surfaces of any shape while providing high EMI shielding efficiency.
Abstract: Materials with good flexibility and high conductivity that can provide electromagnetic interference (EMI) shielding with minimal thickness are highly desirable, especially if they can be easily processed into films. Two-dimensional metal carbides and nitrides, known as MXenes, combine metallic conductivity and hydrophilic surfaces. Here, we demonstrate the potential of several MXenes and their polymer composites for EMI shielding. A 45-micrometer-thick Ti3C2Tx film exhibited EMI shielding effectiveness of 92 decibels (>50 decibels for a 2.5-micrometer film), which is the highest among synthetic materials of comparable thickness produced to date. This performance originates from the excellent electrical conductivity of Ti3C2Tx films (4600 Siemens per centimeter) and multiple internal reflections from Ti3C2Tx flakes in free-standing films. The mechanical flexibility and easy coating capability offered by MXenes and their composites enable them to shield surfaces of any shape while providing high EMI shielding efficiency.
3,251 citations
TL;DR: For the first time, an efficient and facile approach is reported to fabricate freestanding, flexible, and hydrophobic MXene foam with reasonable strength by assembling MXene sheets into films followed by a hydrazine-induced foaming process.
Abstract: Ultrathin, lightweight, and flexible electromagnetic-interference (EMI) shielding materials are urgently required to manage increasingly serious radiation pollution. 2D transition-metal carbides (MXenes) are considered promising alternatives to graphene for providing excellent EMI-shielding performance due to their outstanding metallic electrical conductivity. However, the hydrophilicity of MXene films may affect their stability and reliability when applied in moist or wet environments. Herein, for the first time, an efficient and facile approach is reported to fabricate freestanding, flexible, and hydrophobic MXene foam with reasonable strength by assembling MXene sheets into films followed by a hydrazine-induced foaming process. In striking contrast to well-known hydrophilic MXene materials, the MXene foams surprisingly exhibit hydrophobic surfaces and outstanding water resistance and durability. More interestingly, a much enhanced EMI-shielding effectiveness of ≈70 dB is achieved for the lightweight MXene foam as compared to its unfoamed film counterpart (53 dB) due to the highly efficient wave attenuation in the favorable porous structure. Therefore, the hydrophobic, flexible, and lightweight MXene foam with an excellent EMI-shielding performance is highly promising for applications in aerospace and portable and wearable smart electronics.
1,241 citations
TL;DR: A carefully designed aqueous droplet light heating system along with a thorough mathematical procedure leads to a precise determination of internal light-to-heat conversion efficiency of a variety of nanomaterials, suggesting that MXene is a very promising light- to- Heat conversion material and thus deserves more research attention toward practical applications.
Abstract: MXene, a new series of 2D material, has been steadily advancing its applications to a variety of fields, such as catalysis, supercapacitor, molecular separation, electromagnetic wave interference shielding. This work reports a carefully designed aqueous droplet light heating system along with a thorough mathematical procedure, which combined leads to a precise determination of internal light-to-heat conversion efficiency of a variety of nanomaterials. The internal light-to-heat conversion efficiency of MXene, more specifically Ti3C2, was measured to be 100%, indicating a perfect energy conversion. Furthermore, a self-floating MXene thin membrane was prepared by simple vacuum filtration and the membrane, in the presence of a rationally chosen heat barrier, produced a light-to-water-evaporation efficiency of 84% under one sun irradiation, which is among the state of art energy efficiency for similar photothermal evaporation system. The outstanding internal light-to-heat conversion efficiency and great light...
1,079 citations
TL;DR: Self-aligned in situ reduced graphene oxide (rGO)/polymer nanocomposites with the engineered structure and properties present high performance electromagnetic interference shielding with a remarkable shilding efficiency of 38 dB.
Abstract: Nanocomposites that contain reinforcements with preferred orientation have attracted significant attention because of their promising applications in a wide range of multifunctional fields. Many efforts have recently been focused on developing facile methods for preparing aligned graphene sheets in solvents and polymers because of their fascinating properties including liquid crystallinity and highly anisotropic characteristics. Self-aligned in situ reduced graphene oxide (rGO)/polymer nanocomposites are prepared using an all aqueous casting method. A remarkably low percolation threshold of 0.12 vol% is achieved in the rGO/epoxy system owing to the uniformly dispersed, monolayer graphene sheets with extremely high aspect ratios (>30000). The self-alignment into a layered structure at above a critical filler content induces a unique anisotropy in electrical and mechanical properties due to the preferential formation of conductive and reinforcing networks along the alignment direction. Accompanied by the anisotropic electrical conductivities are exceptionally high dielectric constants of over 14000 with 3 wt% of rGO at 1 kHz due to the charge accumulation at the highly-aligned conductive filler/insulating polymer interface according to the Maxwell-Wagner-Sillars polarization principle. The highly dielectric rGO/epoxy nanocomposites with the engineered structure and properties present high performance electromagnetic interference shielding with a remarkable shilding efficiency of 38 dB.
1,011 citations