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Browsing Department of Mechanical and Energy Engineering by Subject "2D materials"
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Item 2D MXenes: Tunable Mechanical and Tribological Properties(Wiley, 2021-04-28) Wyatt, Brian C.; Rosenkranz, Andreas; Anasori, Babak; Mechanical and Energy Engineering, School of Engineering and Technology2D transition metal carbides, nitrides, and carbonitrides, known as MXenes, were discovered in 2011 and have grown to prominence in energy storage, catalysis, electromagnetic interference shielding, wireless communications, electronic, sensors, and environmental and biomedical applications. In addition to their high electrical conductivity and electrochemically active behavior, MXenes' mechanical properties, flexibility, and strong adhesion properties play crucial roles in almost all of these growing applications. Although these properties prove to be critical in MXenes' impressive performance, the mechanical and tribological understanding of MXenes, as well as their relation to the synthesis process, is yet to be fully explored. Here, a fundamental overview of MXenes' mechanical and tribological properties is provided and the effects of MXenes' compositions, synthesis, and processing steps on these properties are discussed. Additionally, a critical perspective of the compositional control of MXenes for innovative structural, low-friction, and low-wear performance in current and upcoming applications of MXenes is provided. It is established here that the fundamental understanding of MXenes' mechanical and tribological behavior is essential for their quickly growing applications.Item High-Entropy 2D Carbide MXenes: TiVNbMoC3 and TiVCrMoC3(ACS, 2021-06) Nemani, Srinivasa Kartik; Zhang, Bowen; Wyatt, Brian C.; Hood, Zachary D.; Manna, Sukrita; Khaledialidusti, Rasoul; Hong, Weichen; Sternberg, Michael G.; Sankaranarayanan, Subramanian K. R. S.; Anasori, Babak; Mechanical and Energy Engineering, School of Engineering and TechnologyTwo-dimensional (2D) transition metal carbides and nitrides, known as MXenes, are a fast-growing family of 2D materials. MXenes 2D flakes have n + 1 (n = 1–4) atomic layers of transition metals interleaved by carbon/nitrogen layers, but to-date remain limited in composition to one or two transition metals. In this study, by implementing four transition metals, we report the synthesis of multi-principal-element high-entropy M4C3Tx MXenes. Specifically, we introduce two high-entropy MXenes, TiVNbMoC3Tx and TiVCrMoC3Tx, as well as their precursor TiVNbMoAlC3 and TiVCrMoAlC3 high-entropy MAX phases. We used a combination of real and reciprocal space characterization (X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and scanning transmission electron microscopy) to establish the structure, phase purity, and equimolar distribution of the four transition metals in high-entropy MAX and MXene phases. We use first-principles calculations to compute the formation energies and explore synthesizability of these high-entropy MAX phases. We also show that when three transition metals are used instead of four, under similar synthesis conditions to those of the four-transition-metal MAX phase, two different MAX phases can be formed (i.e., no pure single-phase forms). This finding indicates the importance of configurational entropy in stabilizing the desired single-phase high-entropy MAX over multiphases of MAX, which is essential for the synthesis of phase-pure high-entropy MXenes. The synthesis of high-entropy MXenes significantly expands the compositional variety of the MXene family to further tune their properties, including electronic, magnetic, electrochemical, catalytic, high temperature stability, and mechanical behavior.Item High-temperature stability and phase transformations of titanium carbide (Ti3C2Tx) MXene(IOP, 2021-06) Wyatt, Brian C.; Nemani, Srinivasa Kartik; Desai, Krishay; Kaur, Harpreet; Zhang, Bowen; Anasori, Babak; Mechanical and Energy Engineering, School of Engineering and TechnologyTwo-dimensional (2D) transition metal carbides, nitrides, and carbonitrides, known as MXenes, are under increasing pressure to meet technological demands in high-temperature applications, as MXenes can be considered to be one of the few ultra-high temperature 2D materials. Although there are studies on the stability of their surface functionalities, there is currently a gap in the fundamental understanding of their phase stability and transformation of MXenes' metal carbide core at high temperatures (>700 °C) in an inert environment. In this study, we conduct systematic annealing of Ti3C2TxMXene films in which we present the 2D MXene flake phase transformation to ordered vacancy superstructure of a bulk three-dimensional (3D) Ti2C and TiCycrystals at 700 °C ⩽T⩽ 1000 °C with subsequent transformation to disordered carbon vacancy cubic TiCyat higher temperatures (T> 1000 °C). We annealed Ti3C2TxMXene films made from the delaminated MXene single-flakes as well as the multi-layer MXene clay in a controlled environment through the use ofin situhot stage x-ray diffraction (XRD) paired with a 2D detector (XRD2) up to 1000 °C andex situannealing in a tube furnace and spark plasma sintering up to 1500 °C. Our XRD2analysis paired with cross-sectional scanning electron microscope imaging indicated the resulting nano-sized lamellar and micron-sized cubic grain morphology of the 3D crystals depend on the starting Ti3C2Txform. While annealing the multi-layer clay Ti3C2TxMXene creates TiCygrains with cubic and irregular morphology, the grains of 3D Ti2C and TiCyformed by annealing Ti3C2TxMXene single-flake films keep MXenes' lamellar morphology. The ultrathin lamellar nature of the 3D grains formed at temperatures >1000 °C can pave way for applications of MXenes as a stable carbide material 2D additive for high-temperature applications.Item MXenes: The two-dimensional influencers(Elsevier, 2022) Firouzjaei, Mostafa Dadashi; Karimiziarani, Mohammadsepehr; Moradkhani, Hamid; Elliott, Mark; Anasori, Babak; Mechanical and Energy Engineering, Purdue School of Engineering and TechnologyMXenes have significantly impacted materials science and nanotechnology since their discovery in 2011. Theoretical calculations have predicted more than 100 possible compositions of MXenes and lab-scale fabrication of more than 40 MXene structures has been reported to date. The unique characteristics of MXenes have made them an ideal fit for a wide variety of applications, including energy storage, environmental, electronics, communications, gas and liquid separations and adsorption, biomedical, and optoelectronics. MXene attracted many researchers, and as a result, publication trends on MXene have grown exponentially in recent years. By 2021, MXenes have already shown promise in several research areas, including energy storage devices, electromagnetic interference shielding, nanocomposites, and hybrid materials. In parallel, new applications are emerging where MXenes outperform other nanomaterials, such as in tribology. MXene compositions are also being expanded rapidly. Here, we briefly overview the history, properties, trends, and application of MXenes to better understand their potentials and familiarize new audiences with this 2D material family.Item Perspectives of 2D MXene Tribology(Wiley, 2023) Rosenkranz, Andreas; Righi, Maria Clelia; Sumant, Anirudha V.; Anasori, Babak; Mochalin, Vadym N.; Mechanical and Energy Engineering, Purdue School of Engineering and TechnologyThe large and rapidly growing family of two-dimensional early transition metal carbides, nitrides, and carbonitrides (MXenes) raises significant interest in the materials science and chemistry of materials communities. Discovered a little more than a decade ago, MXenes have already demonstrated outstanding potential in various applications ranging from energy storage to biology and medicine. The past two years have witnessed increased experimental and theoretical efforts toward studying MXenes’ mechanical and tribological properties when used as lubricant additives, reinforcement phases in composites, or solid lubricant coatings. Although research on the understanding of the friction and wear performance of MXenes under dry and lubricated conditions is still in its early stages, it has experienced rapid growth due to the excellent mechanical properties and chemical reactivities offered by MXenes that make them adaptable to being combined with other materials, thus boosting their tribological performance. In this perspective, we summarize the most promising results in the area of MXene tribology, outline future important problems to be pursued further, and provide methodological recommendations that we believe could be useful for experts, as well as newcomers to MXenes research, in particular, to the emerging area of MXene tribology.Item Sculpting Liquids with Two-Dimensional Materials: The Assembly of Ti3C2Tx MXene Sheets at Liquid–Liquid Interfaces(ACS, 2019-10) Cain, Jeffrey D.; Azizi, Amin; Maleski, Kathleen; Anasori, Babak; Glazer, Emily C.; Kim, Paul Y.; Gogotski, Yury; Helms, Brett A.; Russell, Thomas P.; Zettl, Alex; Mechanical Engineering and Energy, School of Engineering and TechnologyThe self-assembly of nanoscale materials at the liquid–liquid interface allows for fabrication of three-dimensionally structured liquids with nearly arbitrary geometries and tailored electronic, optical, and magnetic properties. Two-dimensional (2D) materials are highly anisotropic, with thicknesses on the order of a nanometer and lateral dimensions upward of hundreds of nanometers to micrometers. Controlling the assembly of these materials has direct implications for their properties and performance. We here describe the interfacial assembly and jamming of Ti3C2Tx MXene nanosheets at the oil–water interface. Planar, as well as complex, programmed three-dimensional all-liquid objects are realized. Our approach presents potential for the creation of all-liquid 3D-printed devices for possible applications in all-liquid electrochemical and energy storage devices and electrically active, all-liquid fluidics that exploits the versatile structure, functionality, and reconfigurability of liquids.Item Ti3C2Tx MXene Polymer Composites for Anticorrosion: An Overview and Perspective(American Chemical Society, 2022) Amin, Ihsan; van den Brekel, Hidde; Nemani, Kartik; Batyrev, Erdni; de Vooys, Arnoud; van der Weijde, Hans; Anasori, Babak; Shiju, N. Raveendran; Mechanical and Energy Engineering, School of Engineering and TechnologyAs the most studied two-dimensional (2D) material from the MXene family, Ti3C2Tx has constantly gained interest from academia and industry. Ti3C2Tx MXene has the highest electrical conductivity (up to 24,000 S cm-1) and one of the highest stiffness values with a Young's modulus of ∼ 334 GPa among water-dispersible conductive 2D materials. The negative surface charge of MXene helps to disperse it well in aqueous and other polar solvents. This solubility across a wide range of solvents, excellent interface interaction, tunable surface functionality, and stability with other organic/polymeric materials combined with the layered structure of Ti3C2Tx MXene make it a promising material for anticorrosion coatings. While there are many reviews on Ti3C2Tx MXene polymer composites for catalysis, flexible electronics, and energy storage, to our knowledge, no review has been published yet on MXenes' anticorrosion applications. In this brief report, we summarize the current progress and the development of Ti3C2Tx polymer composites for anticorrosion. We also provide an outlook and discussion on possible ways to improve the exploitation of Ti3C2Tx polymer composites as anticorrosive materials. Finally, we provide a perspective beyond Ti3C2Tx MXene composition for the development of future anticorrosion coatings.Item Ti3C2Tx solid lubricant coatings in rolling bearings with remarkable performance beyond state-of-the-art materials(Elsevier, 2021-12) Marian, Max; Feile, Klara; Rothammer, Benedict; Bartz, Marcel; Wartzack, Sandro; Seynstahl, Armin; Tremmel, Stephan; Krauß, Sebastian; Merle, Benoit; Böhm, Thomas; Wang, Bo; Wyatt, Brian C.; Anasori, Babak; Rosenkranz, Andreas; Mechanical and Energy Engineering, School of Engineering and TechnologyTwo-dimensional (2D) transition metal carbides, nitrides, and carbonitrides, known as MXenes, are a growing class of 2D materials, which offer great solid lubrication ability for low friction applications due to their weakly bonded multi-layer structure and tribo-layer formation with self-lubricating characteristics. To date, most studies have assessed their tribological response in basic laboratory tests. However, these tests do not adequately reflect the complex geometries, kinematics, and stresses present in machine components. Here, we aim at bridging this gap through assessment of the friction and wear performance of multi-layer Ti3C2Tx MXene solid lubricant coatings used in rolling bearings. MXenes’ tribological response is compared with state-of-the art solid lubricant coatings, which include molybdenum disulfide (MoS2), tungsten-doped hydrogenated amorphous carbon (a-C:H:W), and hydrogen-free, more graphite-like amorphous carbon (a–C). Multi-layer Ti3C2Tx MXene coatings reduce wear on the bearing washers by up to 94%, which can be attributed to the transfer of the lubricious MXene nano-sheets to secondary tribo-contacts of the bearing. While the frictional torque of all solid lubricant coatings is similar during steady-operation, the MXene-coated bearings extend the service life by 30% and 55% compared to MoS2 and DLC, respectively. This contribution demonstrates the ability of MXene solid lubricant coatings to outperform state-of-the-art solid lubricants in dry-running machine components such as rolling bearings.