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Light-driven C-H activation mediated by 2D transition metal dichalcogenides

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arXiv 2022年

作者： Li, Jingang Zhang, Di Guo, Zhongyuan Jiang, Xi Larson, Jonathan M. Zhu, Haoyue Zhang, Tianyi Gu, Yuqian Blankenship, Brian Chen, Min Wu, Zilong Huang, Suichu Kostecki, Robert Minor, Andrew M. Grigoropoulos, Costas P. Akinwande, Deji Terrones, Mauricio Redwing, Joan M. Li, Hao Zheng, Yuebing Materials Science & Engineering Program Texas Materials Institute Walker Department of Mechanical Engineering The University of Texas at Austin AustinTX78712 United States Laser Thermal Laboratory Department of Mechanical Engineering University of California BerkeleyCA94720 United States Tohoku University Sendai980-8577 Japan Materials Sciences Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Chemistry and Biochemistry Baylor University WacoTX76798 United States Department of Materials Science and Engineering The Pennsylvania State University University ParkPA16802 United States Chandra Family Department of Electrical & Computer Engineering The University of Texas at Austin AustinTX78712 United States Department of Materials Science and Engineering University of California BerkeleyCA94720 United States Energy Storage and Distributed Resources Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States National Center for Electron Microscopy Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Center for Two-Dimensional and Layered Materials The Pennsylvania State University University ParkPA16802 United States Department of Physics Department of Chemistry The Pennsylvania State University University ParkPA16802 United States 2D Crystal Consortium Materials Research Institute The Pennsylvania State University University ParkPA16802 United States

C-H bond activation enables the facile synthesis of new chemicals. While C-H activation in short-chain alkanes has been widely investigated, it remains largely unexplored for long-chain organic molecules. Here, we report light-driven C-H activation in complex organic materials mediated by 2D transition metal dichalcogenides (TMDCs) and the resultant solid-state synthesis of luminescent carbon dots in a spatially-resolved fashion. We unravel the efficient H adsorption and a lowered energy barrier of C-C coupling mediated by 2D TMDCs to promote C-H activation. Our results shed light on 2D materials for C-H activation in organic compounds for applications in organic chemistry, environmental remediation, and photonic materials. © 2022, CC BY-NC-SA.

关键词： Chemical activation

Tailoring High Precision Polynomial Architected Material Constitutive Responses Via Inverse Design

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SSRN

SSRN 2024年

作者： MacNider, Brianna C. Frankel, Ian Qian, Kai Pozos, Alan Santos, Aketzali Kim, H. Alicia Boechler, Nicholas Department of Mechanical and Aerospace Engineering University of California 9500 Gilman Drive La Jolla San DiegoCA92093 United States Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas Instituto Politécnico Nacional Mexico City Mexico Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Culhuacan Instituto Politécnico Nacional Mexico City Mexico Department of Structural Engineering University of California San Diego 9500 Gilman Drive San DiegoCA92093 United States Program in Materials Science and Engineering University of California San Diego 9500 Gilman Drive San DiegoCA92093 United States

The design of specified nonlinear mechanical responses into a structure or material is a highly sought after capability, which would have a significant impact in areas such as wave tailoring in metamaterials, impact mitigation, soft robotics, and biomedicine. Here, we present a topology optimization approach to design structures for desired polynomial nonlinear behavior, wherein we formulate the problem in such a way as to decouple the nonlinear response from the stiffness. We show results across qualitatively different polynomial behaviors while achieving a high degree of precision, creating a path toward analytically tractable nonlinear dynamical systems. The approach enables access to previously difficult to design for, or hitherto unachieved, nonlinear behavior via optimized structures, which can furthermore be incorporated as unit cells of designer materials with tailored nonlinear properties. © 2024, The Authors. All rights reserved.

关键词： Metamaterials

Enhancing mechanical properties and corrosion performance of AA6063 aluminum alloys through constrained groove pressing technique

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Transactions of Nonferrous Metals Society of China 2020年第7期30卷 1790-1802页

作者： Ren-jie FAN Shokouh ATTARILAR Mahmoud SHAMSBORHAN Mahmoud EBRAHIMI Ceren GODE Hatice VarolOZKAVAK Department of Mechanical Engineering Tongling Vocational and Technical CollegeTongling 244061China School of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran Department of Engineering Mahabad BranchIslamic Azad UniversityMahabadIran Department of Mechanical Engineering University of ZakhoZakhoKurdistan RegionIraq Department of Mechanical Engineering Faculty of EngineeringUniversity of MaraghehMaraghehIran School of Denizli Vocational Technology Program of MachinePamukkale UniversityDenizliTurkey Department of Mechanical and Metal Technology Technical Sciences Vocational SchoolIsparta University of Applied SciencesIspartaTurkey

The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity is considerably decreased after the first pass, while subsequent passes result in better hardness behavior for the processed material. Also, the elongated grains formed in the first pass of the CGP are gradually converted to the equiaxed counterparts by adding pass numbers. Eventually, higher corrosion resistance of the sample by imposing the CGP process is related to the quick formation of passivation film and the change in the morphology of the second phase and precipitates which hinder their electrochemical reactions and decrease the potential localized attack sites.

关键词： mechanical properties corrosion resistance aluminum alloy constrained groove pressing technique grain refinement hardness distribution homogeneity

Breakdown of Conventional Winding Number Calculation in One-Dimensional Lattices with Interactions Beyond Nearest Neighbors

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arXiv 2023年

作者： Alisepahi, Amir Rajabpoor Sarkar, Siddhartha Sun, Kai Ma, Jihong Department of Mechanical Engineering University of Vermont 33 Colchester Ave BurlingtonVT05405 United States Department of Physics University of Michigan 450 Church St. Ann ArborMI48109 United States Department of Physics University of Vermont 33 Colchester Ave BurlingtonVT05405 United States Materials Science Program University of Vermont 33 Colchester Ave BurlingtonVT05405 United States

Topological insulators hold promises to realize exotic quantum phenomena in electronic, photonic, and phononic systems. Conventionally, topological indices, such as winding numbers, have been used to predict the number of topologically protected domain-wall states (TPDWSs) in topological insulators, a signature of the topological phenomenon called bulk-edge correspondence. Here, we demonstrate theoretically and experimentally that the number of TPDWSs in a mechanical Su-Schrieffer-Heeger (SSH) model can be higher than the winding number depending on the strengths of beyond-nearest-neighbor interactions, revealing the breakdown of the winding number prediction. Alternatively, we resort to the Berry connection to accurately characterize the number and spatial features of TPDWSs in SSH systems, further confirmed by the Jackiw-Rebbi theory proving that the multiple TPDWSs correspond to the bulk Dirac cones. Our findings deepen the understanding of complex network dynamics and offer a generalized paradigm for precise TPDWS prediction in potential applications involving localized vibrations, such as drug delivery and quantum computing. © 2023, CC BY.

关键词： Topology

Mid-wave to near-IR optoelectronic properties and epsilon-near-zero behavior in indium-doped cadmium oxide

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Physical Review materials 2021年第3期5卷 035202-035202页

作者： Angela Cleri John Tomko Kathleen Quiambao-Tomko Mario V. Imperatore Yanglin Zhu J. Ryan Nolen Joshua Nordlander Joshua D. Caldwell Zhiqiang Mao Noel C. Giebink Kyle P. Kelley Evan L. Runnerstrom Patrick E. Hopkins Jon-Paul Maria Penn State University Department of Materials Science and Engineering University Park Pennsylvania 16802 USA University of Virginia Department of Materials Science and Engineering Charlottesville Virginia 22904 USA Penn State University Department of Electrical Engineering University Park Pennsylvania 16802 USA Penn State University Department of Physics University Park Pennsylvania 16802 USA Vanderbilt University Interdisciplinary Materials Science Program Nashville Tennessee 37235 USA Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee 37830 USA Army Research Office DEVCOM US Army Research Laboratory Research Triangle Park North Carolina 27709 USA University of Virginia Department of Mechanical and Aerospace Engineering Charlottesville Virginia 22904 USA University of Virginia Department of Physics Charlottesville Virginia 22904 USA

Indium-doped cadmium oxide (In:CdO) thin films exhibit tunable epsilon-near-zero (ENZ) modal frequencies across a wide spectral range, bridging the mid-wave and near-infrared (IR). In:CdO thin films are prepared by reactive cosputtering from metallic Cd and In targets using high-power impulse magnetron sputtering (HiPIMS) and radio frequency sputtering, respectively. Using this approach, CdO thin films with carrier concentrations ranging from 2.3×1019 to 4.0×1020cm–3 and mobilities ranging from 300 to 400cm2/Vs are readily achieved. UV-VIS absorption spectra are used to measure optical bandgap, revealing a Burstein-Moss shift of 0.58 eV across the doping range investigated. Optical measurements demonstrate the tunability of near-perfect plasmonic ENZ absorption across the mid-wave and into the near-IR spectral ranges by controlling the carrier concentration through doping, while tuning the film thickness for impedance matching. In comparison to other dopants that can be introduced to HiPIMS-deposited CdO, In offers the largest range of carrier concentrations while maintaining high mobility, thus allowing for the widest accessibility of the IR spectrum of a single plasmonic material grown by sputtering.

关键词： Plasmonics Reflectivity X-ray diffraction

Weak-value amplification for the optical signature of topological phase transitions

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Photonics Research 2020年第12期8卷 I0015-I0022页

作者： WEIJIE WU SHIZHEN CHEN WENHAO XU ZHENXING LIU RUNNAN LOU LIHUA SHEN HAILU LUO SHUANGCHUN WEN XIAOBO YIN Laboratory for Spin Photonics School of Physics and ElectronicsHunan UniversityChangsha 410082China Department of Mechanical Engineering University of ColoradoBoulderColorado 80309USA Materials Science and Engineering Program University of ColoradoBoulderColorado 80309USA

We show that weak measurements can be used to measure the tiny signature of topological phase *** signature is an in-plane photonic spin Hall effect,which can be described as a consequence of a Berry *** is also parallel to the propagation direction of a light *** imaginary part of the weak value can be used to analyze ultrasmall longitudinal phase shifts in different topological *** optical signatures are related to the Chern number and bandgaps;we also use a preselection and postselection technique on the spin state to enhance the original *** weak amplification technique offers a potential way to determine the spin and valley properties of charge carriers,Chern numbers,and topological phases by direct optical measurement.

关键词： signature topological transitions

The connection between polymer collapse and the onset of jamming

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arXiv 2023年

作者： Grigas, Alex T. Fisher, Aliza Shattuck, Mark D. O’Hern, Corey S. Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Benjamin Levich Institute and Physics Department The City College of New York New YorkNY10031 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States

Previous studies have shown that the interiors of proteins are densely packed, reaching packing fractions that are as large as those found for static packings of individual amino-acid-shaped particles. How can the interiors of proteins take on such high packing fractions given that amino acids are connected by peptide bonds and many amino acids are hydrophobic with attractive interactions? We investigate this question by comparing the structural and mechanical properties of collapsed attractive disk-shaped bead-spring polymers to those of three reference systems: static packings of repulsive disks, of attractive disks, and of repulsive disk-shaped bead-spring polymers. We show that attractive systems quenched to temperatures below the glass transition T Tg and static packings of both repulsive disks and bead-spring polymers possess similar interior packing fractions. Previous studies have shown that static packings of repulsive disks are isostatic at jamming onset, i.e. the number of contacts Nc matches the number of degrees of freedom, which strongly influences their mechanical properties. We find that repulsive polymers are hypostatic at jamming onset, but effectively isostatic when including quartic modes. While attractive disk and polymer packings are hyperstatic, we identify a definition for interparticle contacts for which they can also be considered as effectively isostatic. As a result, we show that the mechanical properties (e.g. scaling of the potential energy with excess contact number and low-frequency contribution to the density of vibrational modes) of weakly attractive disk and polymer packings are similar to those of isostatic repulsive disk and polymer packings. Our results demonstrate that static packings generated via attractive collapse or compression of repulsive particles possess similar structural and mechanical properties. © 2023, CC BY.

关键词： Amino acids

Moiré exciton polaron engineering via twisted hBN

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arXiv 2024年

作者： Cho, Minhyun Datta, Biswajit Han, Kwanghee Chand, Saroj B. Adak, Pratap Chandra Yu, Sichao Li, Fengping Watanabe, Kenji Taniguchi, Takashi Hone, James Jung, Jeil Grosso, Gabriele Kim, Young Duck Menon, Vinod M. Department of Physics Kyung Hee University 26 Kyungheedae-ro Seoul02447 Korea Republic of Department of Physics City College of New York New YorkNY10031 United States Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Department of Physics Department of Smart Cities University of Seoul Seoul02504 Korea Republic of Research Center for Electronic and Optical Materials National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Department of Mechanical Engineering Columbia University New YorkNY10027 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States Department of Information Display Kyung Hee University Seoul02447 Korea Republic of

Twisted hexagonal boron nitride (thBN) exhibits emergent ferroelectricity due to the formation of moiré superlattices with alternating AB and BA domains. These domains possess electric dipoles, leading to a periodic electrostatic potential that can be imprinted onto other 2D materials placed in its proximity. Here we demonstrate the remote imprinting of moiré patterns from twisted hexagonal boron nitride (thBN) onto monolayer MoSe2 and investigate the resulting changes in the exciton properties. We confirm the imprinting of moiré patterns on monolayer MoSe2 via proximity using Kelvin probe force microscopy (KPFM) and hyperspectral photoluminescence (PL) mapping. By developing a technique to create large ferroelectric domain sizes ranging from 1 µm to 8.7 µm, we achieve unprecedented potential modulation of ∼ 387±52 meV. We observe the formation of exciton polarons due to charge redistribution caused by the antiferroelectric moiré domains and investigate the optical property changes induced by the moiré pattern in monolayer MoSe2 by varying the moiré pattern size down to ∼110 nm. Our findings highlight the potential of twisted hBN as a platform for controlling the optical and electronic properties of 2D materials for optoelectronic and valleytronic applications. © 2024, CC BY-NC-ND.

关键词： Boron nitride

Experimental Investigation of Lord Kelvin’s Isentropic Cooling and Heating Expression in Tensile Bars for Two engineering Alloys

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arXiv 2023年

作者： Burns, S.J. Pratt, Christine E. Carrock, Joseph Gagnon, Jean-Philippe Sefkow, A.B. Materials Science Program College of Arts Science and Engineering University of Rochester RochesterNY14627 United States Department of Mechanical Engineering University of Rochester 236 Hopeman Hall RochesterNY14627 United States Field Application Engineering Telops GenevaNY14456 United States Systems Engineering Telops 100-2600 St-Jean-Baptiste Ave. QuébecQCG2E 6J5 Canada Laboratory for Laser Energetics University of Rochester 250 E. River Rd. RochesterNY14623 United States Department of Physics and Astronomy University of Rochester 206 Bausch and Lomb Hall RochesterNY14627 United States Department of Computer Science University of Rochester 2513 Wegmans Hall RochesterNY14627 United States

Solids when rapidly and elastically stressed change temperature, the effect proposed by Lord Kelvin is adiabatic thermo-elastic cooling or heating depending on the sign of the stress. A fast sensitive IR camera has measured temperature both decreasing and increasing. Temperature measurements made from the reversible, elastic part of the stress-strain curve during fast uniaxial tensile loading have been investigated. The isentropic temperature cooling from the loading curve is recovered by heating after the specimen fractures when the load is released. These measurements establish for the first time isentropic thermal recovery in two engineering alloys. The materials tested are an AISI 4340 steel and an aluminum 2024 alloy. Measurements of the isentropic thermo-elastic stress cooling are -0.61 K/GPa for steel and -1.7 K/GPa for aluminum alloy. The isentropic thermo-elastic stress heating is -1.16 K/GPa for steel and -1.6 K/GPa for aluminum alloy. These values are compared to Lord Kelvin’s theoretical thermodynamic prediction. Comparisons are also to equations of state tables. The experimental values are slightly below theoretical predictions. The isentropic, elastic part of the temperature is fully recoverable even after extensive plastic deformation upon fracture. Copyright © 2023, The Authors. All rights reserved.

关键词： Cooling