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Jana A, Kearney LT, Naskar AK, Grossman JC, Ferralis N. Effect of Methyl Groups on Formation of Ordered or Layered Graphitic Materials from Aromatic Molecules. Small 2023; 19:e2302985. [PMID: 37357175 DOI: 10.1002/smll.202302985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/12/2023] [Indexed: 06/27/2023]
Abstract
Developing functionally complex carbon materials from small aromatic molecules requires an understanding of how the chemistry and structure of its constituent molecules evolve and crosslink, to achieve a tailorable set of functional properties. Here, molecular dynamics (MD) simulations are used to isolate the effect of methyl groups on condensation reactions during the oxidative process and evaluate the impact on elastic modulus by considering three monodisperse pyrene-based systems with increasing methyl group fraction. A parameter to quantify the reaction progression is designed by computing the number of new covalent bonds formed. Utilizing the previously developed MD framework, it is found that increasing methylation leads to an almost doubling of bond formation, a larger fraction of the new bonds oriented in the direction of tensile stress, and a higher basal plane alignment of the precursor molecules along the direction of tensile stress, resulting in enhanced tensile modulus. Additionally, via experiments, it is demonstrated that precursors with a higher fraction of methyl groups result in a higher alignment of molecules. Moreover, increased methylation results in the lower spread of single molecule alignment which may lead to smaller variations in tensile modulus and more consistent properties in carbon materials derived from methyl-rich precursors.
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Affiliation(s)
- Asmita Jana
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Logan T Kearney
- Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Amit K Naskar
- Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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2
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Patil JJ, Lu Z, Zachman MJ, Chen N, Reeves KS, Jana A, Revia G, MacDonald B, Keller BD, Lara-Curzio E, Grossman JC, Ferralis N. Chemical and Physical Drivers for Improvement in Permeance and Stability of Linker-Free Graphene Oxide Membranes. Nano Lett 2023. [PMID: 37399449 DOI: 10.1021/acs.nanolett.3c01087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Graphene oxide (GO) is a promising membrane material for chemical separations, including water treatment. However, GO has often required postsynthesis chemical modifications, such as linkers or intercalants, to improve either the permeability, performance, or mechanical integrity of GO membranes. In this work, we explore two different feedstocks of GO to investigate chemical and physical differences, where we observe up to a 100× discrepancy in the permeability-mass loading trade-off while maintaining nanofiltration capacity. GO membranes also show structural stability and chemical resilience to harsh pH conditions and bleach treatment. We probe GO and the resulting assembled membranes through a variety of characterization approaches, including a novel scanning-transmission-electron-microscopy-based visualization approach, to connect differences in sheet stacking and oxide functional groups to significant improvements in permeability and chemical stability.
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Affiliation(s)
- Jatin J Patil
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Zhengmao Lu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Michael J Zachman
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830, United States
| | - Ningxin Chen
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Kimberly S Reeves
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830, United States
| | - Asmita Jana
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Griselda Revia
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Materials, Oxford University, Parks Road, Oxford OX1 3PH, United Kingdom
| | - Brandon MacDonald
- Via Separations Inc, 165 Dexter Ave, Watertown, Massachusetts 02472, United States
| | - Brent D Keller
- Via Separations Inc, 165 Dexter Ave, Watertown, Massachusetts 02472, United States
| | - Edgar Lara-Curzio
- Energy Science & Technology Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Via Separations Inc, 165 Dexter Ave, Watertown, Massachusetts 02472, United States
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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3
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Jana A, Zhu T, Wang Y, Adams JJ, Kearney LT, Naskar AK, Grossman JC, Ferralis N. Atoms to fibers: Identifying novel processing methods in the synthesis of pitch-based carbon fibers. Sci Adv 2022; 8:eabn1905. [PMID: 35302858 PMCID: PMC8932655 DOI: 10.1126/sciadv.abn1905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Understanding and optimizing the key mechanisms used in the synthesis of pitch-based carbon fibers (CFs) are challenging, because unlike polyacrylonitrile-based CFs, the feedstock for pitch-based CFs is chemically heterogeneous, resulting in complex fabrication leading to inconsistency in the final properties. In this work, we use molecular dynamics simulations to explore the processing and chemical phase space through a framework of CF models to identify their effects on elastic performance. The results are in excellent agreement with experiments. We find that density, followed by alignment, and functionality of the molecular constituents dictate the CF mechanical properties more strongly than their size and shape. Last, we propose a previously unexplored fabrication route for high-modulus CFs. Unlike graphitization, this results in increased sp3 fraction, achieved via generating high-density CFs. In addition, the high sp3 fraction leads to the fabrication of CFs with isometric compressive and tensile moduli, enabling their potential applications for compressive loading.
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Affiliation(s)
- Asmita Jana
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Taishan Zhu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yanming Wang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Logan T. Kearney
- Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Amit K. Naskar
- Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jeffrey C. Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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4
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Zang X, Ferralis N, Grossman JC. Electronic, Structural, and Magnetic Upgrading of Coal-Based Products through Laser Annealing. ACS Nano 2022; 16:2101-2109. [PMID: 35077155 DOI: 10.1021/acsnano.1c07693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Most coal-to-product routes require complex thermal treatment to carbonize the raw materials. However, the lack of unified comparison of products made from different kinds of coals downplays the role of initial coal chemistry in high-temperature reactions. Here, we used a CO2 laser to investigate the roles that aromatic content and maturity play in the structural evolution and doping of coals during annealing. Results show that a bituminous coal (DECS 19) with aromatic content and maturity in between higher rank, more mature anthracite (DECS 21) and lower rank, lower maturity lignite (DECS 25) leads to more graphite-like structure observed from the highest 2D peak on the Raman spectrum and conductivity (sheet resistance ∼30 ohm sq-1) after lasing. When nitrogen dopants are incorporated with saturated urea dopants into coals through laser ablation, nitrogen preferentially incorporates at the edge sites of graphitic grains. Furthermore, oxide nanoparticles can be incorporated into the graphitic backbone of coal to modify their electronic and magnetic properties through laser annealing. Leveraging tunable magnetic behavior, we demonstrate a soft actuator using both conductive and magnetic coal-Fe/Co oxide. Through laser annealing, we propose a paradigm to understand and control coal chemistry toward flexible and tunable doping and magnetism.
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Affiliation(s)
- Xining Zang
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
- Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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5
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Straub AP, Bergsman DS, Getachew BA, Leahy LM, Patil JJ, Ferralis N, Grossman JC. Highly Conductive and Permeable Nanocomposite Ultrafiltration Membranes Using Laser-Reduced Graphene Oxide. Nano Lett 2021; 21:2429-2435. [PMID: 33689366 DOI: 10.1021/acs.nanolett.0c04512] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Electrically conductive membranes are a promising avenue to reduce water treatment costs due to their ability to minimize the detrimental impact of fouling, to degrade contaminants, and to provide other additional benefits during filtration. Here, we demonstrate the facile and low-cost fabrication of electrically conductive membranes using laser-reduced graphene oxide (GO). In this method, GO is filtered onto a poly(ether sulfone) membrane support before being pyrolyzed via laser into a conductive film. Laser-reduced GO composite membranes are shown to be equally as permeable to water as the underlying membrane support and possess sheet resistances as low as 209 Ω/□. Application of the laser-reduced GO membranes is demonstrated through greater than 97% removal of a surrogate water contaminant, 25 μM methyl orange dye, with an 8 V applied potential. Furthermore, we show that laser-reduced GO membranes can be further tuned with the addition of p-phenylenediamine binding molecules to decrease the sheet resistance to 54 Ω/□.
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Affiliation(s)
- Anthony P Straub
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - David S Bergsman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Bezawit A Getachew
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Liam M Leahy
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jatin J Patil
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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6
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Zang X, Tai KY, Jian C, Shou W, Matusik W, Ferralis N, Grossman JC. Laser-Induced Tar-Mediated Sintering of Metals and Refractory Carbides in Air. ACS Nano 2020; 14:10413-10420. [PMID: 32806046 DOI: 10.1021/acsnano.0c04295] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Refractory metals and their carbides possess extraordinary chemical and temperature resilience and exceptional mechanical strength. Yet, they are notoriously difficult to employ in additive manufacturing, due to the high temperatures needed for processing. State of the art approaches to manufacture these materials generally require either a high-energy laser or electron beam as well as ventilation to protect the metal powder from combustion. Here, we present a versatile manufacturing process that utilizes tar as both a light absorber and antioxidant binder to sinter thin films of aluminum, copper, nickel, molybdenum, and tungsten powder using a low power (<2W) CO2 laser in air. Films of sintered Al/Cu/Ni metals have sheet resistances of ∼10-1 ohm/sq, while laser-sintered Mo/W-tar thin films form carbide phases. Several devices are demonstrated, including laser-sintered porous copper with a stable response to large strain (3.0) after 150 cycles, and a laserprocessed Mo/MoC(1-x) filament that reaches T ∼1000 °C in open air at 12 V. These results show that tar-mediated laser sintering represents a possible low energy, cost-effective route for engineering refractory materials and one that can easily be extended to additive manufacturing processes.
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Affiliation(s)
- Xining Zang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Kiera Y Tai
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Cuiying Jian
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Mechanical Engineering, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Wan Shou
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Wojciech Matusik
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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7
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Zang X, Jian C, Ingersoll S, Li H, Adams JJ, Lu Z, Ferralis N, Grossman JC. Laser-engineered heavy hydrocarbons: Old materials with new opportunities. Sci Adv 2020; 6:eaaz5231. [PMID: 32494645 PMCID: PMC7182407 DOI: 10.1126/sciadv.aaz5231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 02/07/2020] [Indexed: 05/08/2023]
Abstract
Polycyclic heavy hydrocarbons (HHs) such as coal, tar, and pitch are a family of materials with extremely rich and complex chemistry, representing a massive opportunity for their use in a range of potential applications. The present work shows that optimal selection of initial HHs based on molecular constituents is essential in tuning the material for a particular and targeted electronic application. Combining the selection of feedstock chemistry (H:C and aromatic content) and controlling variable laser treatment parameters (laser power, speed, and focus) lead to full control over the H:C ratio, sp2 concentration, and degree of graphitic stacking order of the products. The broad intertunability of these factors results from a wide distribution of carbon material crystallinity from amorphous to highly graphitic and a broad distribution of electrical conductivity up to 103 S/m.
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Affiliation(s)
- X. Zang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - C. Jian
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Mechanical Engineering, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - S. Ingersoll
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Huashan Li
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
| | - J. J. Adams
- Western Research Institute, Laramie, WY 82072, USA
| | - Z. Lu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - N. Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Corresponding author. (J.C.G.); (N.F.)
| | - J. C. Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Corresponding author. (J.C.G.); (N.F.)
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8
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Alleon J, Flannery DT, Ferralis N, Williford KH, Zhang Y, Schuessler JA, Summons RE. Organo-mineral associations in chert of the 3.5 Ga Mount Ada Basalt raise questions about the origin of organic matter in Paleoarchean hydrothermally influenced sediments. Sci Rep 2019; 9:16712. [PMID: 31723181 PMCID: PMC6853986 DOI: 10.1038/s41598-019-53272-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/30/2019] [Indexed: 11/27/2022] Open
Abstract
Hydrothermal and metamorphic processes could have abiotically produced organo-mineral associations displaying morphological and isotopic characteristics similar to those of fossilized microorganisms in ancient rocks, thereby leaving false-positive evidence for early life in the geological record. Recent studies revealed that geologically-induced alteration processes do not always completely obliterate all molecular information about the original organic precursors of ancient microfossils. Here, we report the molecular, geochemical, and mineralogical composition of organo-mineral associations in a chert sample from the ca. 3.47 billion-year-old (Ga) Mount Ada Basalt, in the Pilbara Craton, Western Australia. Our observations indicate that the molecular characteristics of carbonaceous matter are consistent with hydrothermally altered biological organics, although significantly distinct from that of organic microfossils discovered in a chert sample from the ca. 3.43 Ga Strelley Pool Formation in the same area. Alternatively, the presence of native metal alloys in the chert, previously believed to be unstable in such hydrothermally influenced environments, indicates strongly reducing conditions that were favorable for the abiotic formation of organic matter. Drawing definitive conclusions about the origin of most Paleoarchean organo-mineral associations therefore requires further characterization of a range of natural samples together with experimental simulations to constrain the molecular composition and geological fate of hydrothermally-generated condensed organics.
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Affiliation(s)
- Julien Alleon
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
- Now at Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland.
| | - David T Flannery
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kenneth H Williford
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Yong Zhang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - Roger E Summons
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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9
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Morris OP, Zang X, Gregg A, Keller B, Getachew B, Ingersoll S, Elsen HA, Disko MM, Ferralis N, Grossman JC. Natural Carbon By-Products for Transparent Heaters: The Case of Steam-Cracker Tar. Adv Mater 2019; 31:e1900331. [PMID: 31268196 DOI: 10.1002/adma.201900331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/20/2019] [Indexed: 06/09/2023]
Abstract
Steam-cracker tar (SCT) is a by-product of ethylene production that is in massive quantities globally (>150 × 106 tons per year). With few useful applications, the production of unwanted SCT leads to the need for its costly disposal or burning at the boiler plant. The discovery of new uses for SCT would therefore bring both economic and environmental benefits, although, to date, efforts toward employing SCT in diverse applications have been limited, and progress is further hampered by a lack of understanding of the material itself. Although complex and highly heterogeneous in nature, the molecular composition of SCT has the potential to serve as a diverse and tunable feedstock for wide-ranging applications. Here, a simple solution-processing method for SCT that allows its conductivity and optical properties to be controlled over orders of magnitude is reported. Here, by way of example, the focus is on the production of transparent conductive thin films, which exhibit a wide range of transparencies (23-93%) and sheet resistances (2.5 Ω □-1 to 1.2 kΩ □-1 ) that are tuned by a combination of solution concentration and thermal annealing. As transparent Joule heaters, even without optimization, these SCT devices show competitive performance compared to established technologies such as those based on reduced graphene oxide, and surpass the temperature stability limit of other materials. Furthermore, it is demonstrated that laser annealing can be used to process the SCT films and directly pattern transparent heaters on an arbitrary substrate. These results highlight the potential of SCT as a feedstock material for electronic applications and suggest that broader classes of either naturally occurring carbon or produced carbonaceous by-products could prove useful in a range of applications.
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Affiliation(s)
- Owen P Morris
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Xining Zang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Aoife Gregg
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Brent Keller
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Bezawit Getachew
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Samuel Ingersoll
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Heather A Elsen
- ExxonMobil Research and Engineering Company, Annandale, NJ, 08801, USA
| | - Mark M Disko
- ExxonMobil Research and Engineering Company, Annandale, NJ, 08801, USA
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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10
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Keller BD, Ferralis N, Grossman JC. Rethinking Coal: Thin Films of Solution Processed Natural Carbon Nanoparticles for Electronic Devices. Nano Lett 2016; 16:2951-2957. [PMID: 27031328 DOI: 10.1021/acs.nanolett.5b04735] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Disordered carbon materials, both amorphous and with long-range order, have been used in a variety of applications, from conductive additives and contact materials to transistors and photovoltaics. Here we show a flexible solution-based method of preparing thin films with tunable electrical properties from suspensions of ball-milled coals following centrifugation. The as-prepared films retain the rich carbon chemistry of the starting coals with conductivities ranging over orders of magnitude, and thermal treatment of the resulting films further tunes the electrical conductivity in excess of 7 orders of magnitude. Optical absorption measurements demonstrate tunable optical gaps from 0 to 1.8 eV. Through low-temperature conductivity measurements and Raman spectroscopy, we demonstrate that variable range hopping controls the electrical properties in as-prepared and thermally treated films and that annealing increases the sp(2) content, localization length, and disorder. The measured hopping energies demonstrate electronic properties similar to amorphous carbon materials and reduced graphene oxide. Finally, Joule heating devices were fabricated from coal-based films, and temperatures as high as 285 °C with excellent stability were achieved.
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Affiliation(s)
- Brent D Keller
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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11
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Smith BD, Patil JJ, Ferralis N, Grossman JC. Catalyst Self-Assembly for Scalable Patterning of Sub 10 nm Ultrahigh Aspect Ratio Nanopores in Silicon. ACS Appl Mater Interfaces 2016; 8:8043-8049. [PMID: 26999295 DOI: 10.1021/acsami.6b01927] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Nanoporous silicon (NPSi) has received significant attention for its potential to contribute to a large number of applications, but has not yet been extensively implemented because of the inability of current state-of-the-art nanofabrication techniques to achieve sufficiently small pore size, high aspect ratio, and process scalability. In this work we describe the fabrication of NPSi via a modified metal-assisted chemical etching (MACE) process in which silica-shell gold nanoparticle (SiO2-AuNP) monolayers self-assemble from solution onto a silicon substrate. Exposure to the MACE etchant solution results in the rapid consumption of the SiO2 spacer shell, leaving well-spaced arrays of bare AuNPs on the substrate surface. Particles then begin to catalyze the etching of nanopore arrays without interruption, resulting in the formation of highly anisotropic individual pores. The excellent directionality of pore formation is thought to be promoted by the homogeneous interparticle spacing of the gold core nanocatalysts, which allow for even hole injection and subsequent etching along preferred crystallographic orientations. Electron microscopy and image analysis confirm the ability of the developed technique to produce micrometer-scale arrays of sub 10 nm nanopores with narrow size distributions and aspect ratios of over 100:1. By introducing a scalable process for obtaining high aspect ratio pores in a novel size regime, this work opens the door to implementation of NPSi in numerous devices and applications.
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Affiliation(s)
- Brendan D Smith
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jatin J Patil
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Chemical Engineering, University of Waterloo , 200 University Avenue West, Waterloo, Ontario N2L 6G9, Canada
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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12
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Abstract
Carbon materials are excellent candidates for photovoltaic solar cells: they are Earth-abundant, possess high optical absorption, and maintain superior thermal and photostability. Here we report on solar cells with active layers made solely of carbon nanomaterials that present the same advantages of conjugated polymer-based solar cells, namely, solution processable, potentially flexible, and chemically tunable, but with increased photostability and the possibility to revert photodegradation. The device active layer composition is optimized using ab initio density functional theory calculations to predict type-II band alignment and Schottky barrier formation. The best device fabricated is composed of PC(70)BM fullerene, semiconducting single-walled carbon nanotubes, and reduced graphene oxide. This active-layer composition achieves a power conversion efficiency of 1.3%-a record for solar cells based on carbon as the active material-and we calculate efficiency limits of up to 13% for the devices fabricated in this work, comparable to those predicted for polymer solar cells employing PCBM as the acceptor. There is great promise for improving carbon-based solar cells considering the novelty of this type of device, the high photostability, and the availability of a large number of carbon materials with yet untapped potential for photovoltaics. Our results indicate a new strategy for efficient carbon-based, solution-processable, thin film, photostable solar cells.
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Affiliation(s)
- Marco Bernardi
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA
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13
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Ferralis N, El Gabaly F, Schmid AK, Maboudian R, Carraro C. Real-time observation of reactive spreading of gold on silicon. Phys Rev Lett 2009; 103:256102. [PMID: 20366265 DOI: 10.1103/physrevlett.103.256102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Indexed: 05/29/2023]
Abstract
The spreading of a bilayer gold film propagating outward from gold clusters, which are pinned to clean Si(111), is imaged in real time by low-energy electron microscopy. By monitoring the evolution of the boundary of the gold film at fixed temperature, a linear dependence of the spreading radius on time is found. The measured spreading velocities in the temperature range of 800 < T < 930 K varied from below 100 pm/s to 50 nm/s. We show that the spreading rate is limited by the reaction to form Au silicide, and the spreading velocity is likely regulated by the reconstruction of the gold silicide that occurs at the interface.
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Affiliation(s)
- Nicola Ferralis
- Department of Chemical Engineering, University of California, Berkeley, California 94720, USA.
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Ferralis N, Maboudian R, Carraro C. Evidence of structural strain in epitaxial graphene layers on 6H-SiC(0001). Phys Rev Lett 2008; 101:156801. [PMID: 18999622 DOI: 10.1103/physrevlett.101.156801] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Indexed: 05/27/2023]
Abstract
The early stages of epitaxial graphene layer growth on the Si-terminated 6H-SiC (0001) are investigated by Auger electron spectroscopy (AES) and depolarized Raman spectroscopy. The selection of the depolarized component of the scattered light results in a significant increase in the C-C bond signal over the second order SiC Raman signal, which allows us to resolve submonolayer growth, including individual, localized C=C dimers in a diamondlike carbon matrix for AES C/Si ratio of approximately 3, and a strained graphene layer with delocalized electrons and Dirac single-band dispersion for AES C/Si ratio >6. The linear strain, measured at room temperature, is found to be compressive, which can be attributed to the large difference between the coefficients of thermal expansion of graphene and SiC. The magnitude of the compressive strain can be varied by adjusting the growth time at fixed annealing temperature.
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Affiliation(s)
- Nicola Ferralis
- Department of Chemical Engineering, University of California, Berkeley, California 94720, USA
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Abstract
A process for self-pinning of AuSi eutectic alloy droplets to a Si substrate, induced by a controlled temperature annealing in ultrahigh vacuum, is presented. Surface pinning of AuSi 3D droplets to the Si substrate is found to be a consequence of the readjustment in the chemical composition of the droplets upon annealing, as required to maintain thermodynamic equilibrium at the solid-liquid interface. Structural and morphological changes leading to the pinning of the droplets to the substrate are analyzed. Phase separation is observed upon cooling of the droplets, leading to the formation of amorphous Si-rich channels within the core and the formation of crystalline Si nanoshells on the outside. The mechanism leading to the pinning and surface layering provides new insight into the role of alloying during growth of silicon nanowires and may be relevant to the engineering of nanoscale Si cavities.
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Affiliation(s)
- Nicola Ferralis
- Department of Chemical Engineering, University of California, Berkeley, California 94720, USA
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Curtarolo S, Setyawan W, Ferralis N, Diehl RD, Cole MW. Evolution of topological order in Xe films on a quasicrystal surface. Phys Rev Lett 2005; 95:136104. [PMID: 16197154 DOI: 10.1103/physrevlett.95.136104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Indexed: 05/04/2023]
Abstract
We report results of the first computer simulation studies of a physically adsorbed gas on a quasicrystalline surface Xe on decagonal Al-Ni-Co. The grand canonical Monte Carlo method is employed, using a semiempirical gas-surface interaction, based on conventional combining rules, and the usual Lennard-Jones Xe-Xe interaction. The resulting adsorption isotherms and calculated structures are consistent with the results of LEED experimental data. The evolution of the bulk film begins in the second layer, while the low coverage behavior is epitaxial. This transition from epitaxial fivefold to bulklike sixfold ordering is temperature dependent, occurring earlier (at lower coverage) for the higher temperatures.
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Affiliation(s)
- Stefano Curtarolo
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA.
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