ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Guo-Yu Yang,Shao-Zhe Wang,Hong-Tai Sun,Xu-Ming Yao,Chuan-Bing Li,Yu-Jun Li,Jian-Jun Jiang
MXene aerogels with a porous microstructure are a promising electromagnetic interference (EMI) shielding material due to its low density and excellent electrical conductivity, which has attracted widespread attention. Compared with traditional EMI shielding materials that rely on reflection as the primary mechanism, MXene aerogels with absorption as the dominant mechanism have greater potential for development as a novel EMI shielding material because of its ability to reduce environmental contamination from reflected electromagnetic (EM) waves from materials. In this study, a novel Ti3C2Tx MXene/PEDOT:PSS hybrid aerogel was presented by freeze-drying and thermal annealing using few-layered Ti3C2Tx MXene and the conductive polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). PEDOT:PSS not only improved the gelling ability of Ti3C2Tx but also successfully established a conductive bridge between MXene nanosheets. The experimental results demonstrated that the hybrid aerogel exhibited an obvious porous microstructure, which was beneficial for the multiple scattering of EM waves within the materials. The EMI shielding effectiveness and specific shielding effectiveness reached up to 59 dB and 10,841 dB·cm2·g–1, respectively, while the SER/SET ratio value was only 0.05, indicating superior wave absorption performance. Furthermore, the good impedance matching, due to the electrical conductance loss and polarization loss effect of the composites, plays a critical role in their excellent wave absorption and EMI shielding performance. Therefore, this work provides a practical approach for designing and fabricating lightweight absorption-dominated EMI shielding materials.
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高影响因子
Polymers
·
2021
·Vol. 13
·期 21
·3815
·
IF 4.329
Wanxin Peng,Furui Sun,Yuke Liang,Jian Kang,Jinyao Chen,Wei Wang,Ya Cao,Ming Xiang
In this study, one of the commonly used MXene (Ti3C2Tx) and β nucleated isotactic polypropylene (β-iPP)/MXene composites of different compositions were fabricated. The effects of MXene on non-isothermal crystallization and polymorphic behavior of β-iPP/MXene composites were comparatively studied. The non-isothermal crystallization kinetics indicates that for all samples, the lower cooling rates promote composites to crystallize at higher temperatures. When MXene and β-Nucleating agent (β-NA) are added separately, the crystallization temperature of composites shifts towards higher temperatures at all cooling rates. When MXene and β-NA are added simultaneously, the composite shows different cooling rate dependence, and the effects of improving crystallization temperatures is more obvious under rapid cooling. The activation energy of four samples iPP, iPP/MXene, iPP/β-NA, and iPP/MXene/β-NA were −167.5, −185.5, −233.8, and −218.1 kJ/mol respectively, which agree with the variation tendency of crystallization temperatures. The polymorphic behavior analysis obtained from Differential Scanning calorimetry (DSC) is affected by two factors: the ability to form β-crystals and the thermal stability of β-crystals. Because β-crystals tend to recrystallize to α-crystals below a critical temperature, to eliminate the effect of β-α recrystallization, the melting curves at end temperatures Tend= 50 °C and Tend= 100 °C are comparatively studied. The results show that more thermally unstable β-crystals would participate in β-α recrystallization with higher cooling rates. Moreover, thermal stability of β-crystals is improved by adding MXene. To further verify these findings, samples of three different thermal conditions were synthesized and analyzed by DSC, X-Ray Diffraction (XRD), and Polarized Light Optical Microscopy (PLOM), and the results were consistent with the above findings. New understandings of synthesizing β-iPP/MXene composites with adjustable morphologies and polymorphic behavior were proposed.Keywords:istotactic polypropylene;MXene;nonisothermal crystallization behavior
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JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Tao Zhang,Xin Guo,Brusly Solomon,Mohsen Sharifpur,Li-Zhi Zhang
Hollow fiber membrane-based humidification-dehumidification desalination of seawater is a low-carbon freshwater-harvesting technology that can be powered by low-grade solar energy. Polyvinylidene fluoride (PVDF) can be easily fabricated into membranes and is considered the most promising material for industrial seawater desalination. However, membrane fouling and wetting have always been major obstacles with this technology. In this study, a hydrophobic-hydrophilic MXene/PVDF composite hollow fiber membrane (PVDF-MP) with remarkable antiwetting and antifouling properties was successfully prepared using a chemical grafting method. The interfacial dehydration reaction between the hydrophilic substrate layer (PVDF-OH) and the hydrophobic skin layer (MXene-P [MP]) was verified by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, and a detailed reaction mechanism was provided. The hydrophilic substrate layer decreased moisture transfer resistance, while the hydrophobic skin layer reduced the membrane surface energy and increased the surface roughness . This resulted in a contact angle of 156.2°, which was measured using a new method that accounted for the curvature of the membrane. The superhydrophobic surface possessed a strong repulsive force toward water, and the air gap between the water and membrane impeded pollutant deposition on the inner surface of the membrane. Moreover, the rough surface created high entry pressure and prevented water from entering the membrane pores. Thus, the permeate flux of the PVDF-MP membrane persisted over 120 h during desalination tests, surpassing the performance of traditional materials.
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Small
·
2021
·Vol. 18
·期 5
·2104368
·
IF 13.281
Xin Yang,Changqing Zhang,Dawei Deng,Yueqing Gu,Huan Wang,Qifeng Zhong
Chronic wound healing is an important and basic issue in medical and healthcare fields. Recently, stimuli-responsive hydrogel systems have emerged as promising drug delivery carriers for wound management. However, given to the limited therapeutic outcomes, new hydrogel systems for efficient wound treatment are urgently needed. Here, the development of a 2D MXene-based hydrogel system for highly efficient photo- and magnetic-responsive drug delivery oriented to deep chronic wounds repair is presented. The intelligent responsive MXene-based hydrogel drug delivery system is composed of MXene-wrapped magnetic colloids and poly( N -isopropyl acrylamide)-alginate dual-network hydrogels. It is demonstrated that the MXene-based hydrogel system exhibits multiple response capability and controllable drug delivery ability, which can reduce the toxic side effects of drugs and promote the wound healing process as well. Notably, the practical performance of the MXene-based hydrogel drug delivery system is demonstrated by applying it to the treatment of the full-thickness cutaneous wound and subcutaneous infected wound of the rat model, which indicates the great prospect in clinical wound healing and other related biomedical fields.
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高影响因子
POLYMER COMPOSITES
·
2021
·Vol. 43
·期 1
·84-93
·
IF 3.171
Jiaming Guo,Tingtian Qiu,Chengxingzi Yu,Yu Liu,Chen Ning,Lingqiang Kong,Yan Ma,Liu Liu,Yuhui Ao
An unprecedented electrostatic self-assembly of MXene and SiO 2 on carbon fiber (CF) to enhance the interfacial properties of CF-reinforced epoxy resin composites is disclosed. MXene with negative charge was anchored on the cationized CF surface via a strong electrostatic interaction, followed by synergistic effect of amine-modified SiO 2 (positive charge) to furnish a stable MXene/SiO 2 material with three-dimensional structure, which takes the advantages of high modulus, large specific surface area, and high-surface activity. The involvement of the two nano-materials with different dimensions and morphologies results in synergistic enhancement on mechanical interlocking, leading to excellent chemical bonding connection between CF and resin, which could transfer stress and dissipate energy effectively. Moreover, the surface energy of CF increased from 26.67 to 48.12 mJ/m 2 after assembly of MXene/SiO 2 . Compared with unsized CF/EP composites, the interfacial shear strength, interlaminar shear strength, and flexural strength of CF/MXene/SiO 2 /epoxy (EP) composites were increased by 73.2%, 61.2%, and 39.2%, respectively. Dynamic mechanical analysis poxy (DMA) tests showed that the storage modulus of the CF/MXene/SiO 2 /EP composites was enhanced by 64% compared with CF/EP composites, and the glass-transition temperature of composites was elevated from 147.9 to 151.8°C. This protocol provides a promising strategy for designing advanced CF/EP composites with three-dimensional structure.
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Advanced Composites and Hybrid Materials
·
2021
·Vol. 4
·期 2
·274-285
·
IF 5.693
Gao Qingsen,Pan Yamin,Zheng Guoqiang,Liu Chuntai,Shen Changyu,Liu Xianhu
The prosperous development of smart wearable electronic devices has caused extensive demand for flexible composite films with integrated electromagnetic interference (EMI) shielding and thermal management performances. However, it is still a challenge to prepare flexible composite films with desirable properties. Herein, the flexible multilayered MXene/thermoplastic polyurethane films were prepared via a simple layer-by-layer spraying technique. The multilayered films with 28.6 wt% MXene and 52-µm thickness exhibit high electrical conductivity of 1600 S/m, excellent EMI shielding effectiveness of 50.7 dB in the X-band, and outstanding specific shielding effectiveness of 7276 dB.cm 2 g −1 . Meanwhile, a high in-plane thermal conductivity of 6.31 W/(m.k) and low cross-plane thermal conductivity of 0.42 W/(m.k) were obtained. Besides, the obtained films exhibit excellent Joule heating performance (113 °C) with low voltage (5 V), fast response time (< 10 s), excellent heating stability, and efficient de-icing as well as potential thermal stealth performance. Graphical abstract The multilayered MXene/TPU films were prepared by layer-by-layer spraying and exhibited excellent EMI shielding, thermal conductivity, and management performances.
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高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Tianran Wang,Peitao Dong,Chushu Zhu,Weiye Gao,Pengxing Sha,Yulie Wu,Xuezhong Wu
As an emerging label-free detection technology, surface-enhanced Raman scattering (SERS) has been used for biological detection, food safety, and environmental pollution owing to its high sensitivity, specificity and rapid response. However, traditional SERS substrates are unstable, prone to agglomeration, and demonstrate low productivity and high production cost. In this work, hybrids of a two-dimensional electron gas (2DEG) Ti 3 C 2 T x monolayer and Au nanorods (AuNRs) were fabricated via self-assembly. Ti 3 C 2 T x :AuNRs ratios were prepared, and each hybrid's SERS activity was evaluated through 4-aminothiophenol (pATP) detection. The Ti 3 C 2 T x /AuNRs-1 substrate exhibited the weakest SERS performance, whereas the Ti 3 C 2 T x /AuNRs-3 substrate had the best SERS activity enhancement, with a pATP limit of detection (LOD) of 10 −9 M. When 30 sites on substrates were selected for SERS detection, the relative standard deviation (RSD) was found to be only 7.18 %, revealing the good performance sensitivity and high reproducibility of the Raman signal. The sensitivity of Ti 3 C 2 T x /AuNRs-3 was also assessed with respect to a hazardous chemical, 1,2-bis (4-pyridyl) ethylene (BPE), revealing an LOD of 10 −12 M. For thiram, the LOD of Ti 3 C 2 T x /AuNRs-3 was 10 −8 M, which is considerably lower than the 1 ppm industry safety standard. A relative standard deviation RSD of 7.94 % indicates the high reproducibility and uniformity of the Raman signal of thiram for Ti 3 C 2 T x /AuNRs-3. Compared with the LODs of 10 −5 M and 10 −6 M for commercial substrates T-SERS and Au nanorod arrays (AuNRAs), respectively, the 10 −8 M LOD of our synthesized Ti 3 C 2 T x /AuNRs indicates good sensitivity. Three kinds of pesticides were detected by Ti 3 C 2 T x /AuNRs, and only Raman signal of thiram can be found, revealing the good selectivity for thiram. These results for Ti 3 C 2 T x /AuNRs suggest its potential to serve as a novel SERS platform.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Qi Fan,Ruizheng Zhao,Mengjiao Yi,Ping Qi,Chunxiao Chai,Hao Ying,Jingcheng Hao
Stemming from its unique structure and properties, Ti 3 C 2 -MXenes have stood out from the crowd of electrode materials due to effectively ameliorating imperfections of common ones for excellent energy storage. However, a major stumbling block in the further development of MXene-based supercapacitors is the inherent low capacities caused by severe restacking of nanosheets. Herein, we develop a simple, effective and innovative strategy, namely, introducing both polymerized polypyrrole (PPy) particles and ionic liquid (ILs)-based microemulsion particles as “dual spacers”, to fabricate functionalized Ti 3 C 2 -MXene composite films for high-performance and wide-temperature application in supercapacitors. The PPy particles acting as one “spacer” circumvent restacking issues of MXene nanosheets, while contribute to desirable capacitance of the hybrid material. ILs-based microemulsions spontaneously adsorbing onto PPy-Ti 3 C 2 T x nanosheets are conceived to be one more liquid “spacer” for fast ion diffusion kinetics and absent electrolyte imbibition steps, which is rarely reported in previous research for MXene-based electrode materials. These features endow the composite films with excellent specific capacitance, rate capability and cycling stability between 4 °C and 50 °C. At room temperature, the symmetric supercapacitor device based on the composite films delivers a maximum gravimetric energy density of 31.2 Wh kg −1 (at 1030.4 W kg −1 ) and reserves 91% of the initial specific capacitance with a coulombic efficiency of 91% after 2000 cycles. All these impressive results substantiate that the composite films prepared by ingenious structure design showcase huge potentials in advanced MXene-based supercapacitors using various ionic liquid electrolytes.
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Advanced Composites and Hybrid Materials
·
2021
·Vol. 4
·期 3
·602-613
·
IF 5.693
Guo Yan,Wang Dedong,Bai Tiantian,Liu Hu,Zheng Yanjun,Liu Chuntai,Shen Changyu
Two-dimensional Ti 3 C 2 T x MXene nanosheets with excellent electrical conductivity and layered structure have shown great promising in electromagnetic wave (EMW) absorption. Here, MXene nanosheets with homogeneously anchored NiFe 2 O 4 nanoparticles (NiFe 2 O 4 /MXene) were prepared using facial electrostatic self-assembling and freeze-drying technique. Interestingly, the minimum reflection loss ( RL min ) of paraffin wax-based composites with only 3% NiFe 2 O 4 /MXene reached as low as − 41.83 dB, showing much stronger EMW absorption property than that of MXene nanosheets ( RL min = − 5.03 dB) at the same loading level. This can be mainly ascribed to the existence of NiFe 2 O 4 nanoparticle that can effectively prevent the self-stacking of MXene nanosheets, causing improved conduction loss. Besides, large amounts of heterogeneous interfaces between NiFe 2 O 4 nanoparticle and MXene can also produce additional interface polarization loss. More importantly, magnetic loss arising from the magnetic NiFe 2 O 4 nanoparticle is beneficial for good impedance matching, enabling more EMW to enter into the interior of composites to be dissipated. Furthermore, effective absorption bandwidth in the frequency range of 3.44–18 GHz can be achieved by adjusting the matching thickness of composites with 5% NiFe 2 O 4 /MXene. This study paves a way for preparing high-performance MXene-based EMW absorber at ultralow loading level. Graphical abstract Electrostatic self-assembled NiFe2O4/MXene nanocomposites exhibit excellent electromagnetic wave absorption performance based on the synergistic effect of bifillers
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高影响因子
CARBON
·
2021
·
IF 9.594
Mengyi Peng,Menglei Dong,Wei Wei,Huajie Xu,Chuntai Liu,Changyu Shen
The chemical conversion of the surface termination of 2D transition metal carbides/nitrides (MXenes) has opened up a design space that previously had not been extensively explored for this functional material . Herein, via a simple sealed thermal method, the amino terminated groups were successfully introduced on Ti 3 C 2 MXene surface. The substitution reaction of amino group to hydroxyl group was proposed to elucidate this aminated process. As the amination would reduce the carrier density on the surface of MXene, the electrical conductivity of MXene-NH 2 film decreased, while it still reached a high conductivity of 2.11 × 10 4 S m −1 . This film also possessed an excellent electromagnetic interference shielding effectiveness of 16160 dB cm 2 g −1 . Importantly, although the introduction of amino termination altered Zeta potential value, Zeta potential sign remained negative and the MXene-NH 2 exhibited excellent dispersity in water similar to that of traditional MXenes. Furthermore, the existence of covalent bonds endowed MXene-NH 2 polymer composite film with improved mechanical properties . Compared with that of traditional CMC/MXene film, the tensile strength and fracture energy of CMC/MXene-NH 2 increased by 65.5% and 132.7%, respectively. These results demonstrated that the introduction of amino terminated group on MXene surface would be an effective strategy to obtain higher performance MXene-based films.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Ming-Ke Xu,Ji Liu,Hao-Bin Zhang,Yu Zhang,Xinyu Wu,Zhiming Deng,Zhong-Zhen Yu
Electrically conductive polymer nanocomposites are highly required for efficient electromagnetic interference (EMI) shielding applications. Although two-dimensional transition metal carbide/carbonitride (MXene) nanosheets with metallic electrical conductivity and layered structure show great potential for the construction of interconnected conductance networks in polymer matrices, their preferred stacking feature and intrinsic hydrophilicity inevitably cause poor dispersion in organic polymers, making it challenging to prepare MXene/polymer nanocomposites with high electrical conductivity and satisfactory EMI shielding performances at low MXene contents. Herein, we demonstrate an efficient methodology to prepare highly conductive MXene/polypropylene (PP) nanocomposites with an ultralow percolation threshold for efficient EMI shielding application. By dip-coating MXene nanosheets onto a polyethyleneimine-grafted PP textile, followed by vacuum-assisted compression molding, an interconnected conductance network of MXene nanosheets in the PP matrix is constructed facilely and efficiently. The resultant MXene/PP nanocomposite exhibits an ultralow percolation threshold of 0.027 vol %, a high electrical conductivity of 437.5 S m–1 at a low MXene loading of 2.12 vol %, and an outstanding EMI shielding performance of more than 60 dB within the X-band, superior to most other electrically conductive polymer nanocomposites. This work provides a new approach for fabricating MXene/polymer nanocomposites with outstanding electrical conductivity for high-performance EMI shielding applications.
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高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 3
·720
·
IF 5.076
Yunjia Wang,Jianwen Wang,Qiao Wen
Owing to their unique characteristics, two-dimensional (2-D) materials and their complexes have become very attractive in photoelectric applications. Two-dimensional heterojunctions, as novel 2-D complex materials, have drawn much attention in recent years. Herein, we propose a 2-D heterojunction composed of MXene (Ti2CTx) materials and graphene oxide (GO), and apply it to an Nd:YAG solid-state laser as a saturable absorber (SA) for passive Q-switching. Our results suggest that a nano-heterojunction between MXene and GO was achieved based on morphological characterization, and the advantages of a broadband response, higher stability in GO, and strong interaction with light waves in MXene could be combined. In the passively Q-switched laser study, the single-pulse energy was measured to be approximately 0.79 µJ when the pump power was 3.72 W, and the corresponding peak power was approximately 7.25 W. In addition, the generation of a stable ultrashort pulse down to 109 ns was demonstrated, which is the narrowest pulse among Q-switched solid-state lasers using a 2-D heterojunction SA. Our work indicates that the MXene–GO nano-heterojunction could operate as a promising SA for ultrafast systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe that this work opens up a new approach to designing 2-D heterojunctions and provides insight into the formation of new 2-D materials with desirable photonic properties.Keywords:MXene;saturable absorber;heterojunction;Q-switched;pulsed laser;nonlinear optics;bulk laser
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高影响因子
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