1
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Baer DR, Watts JF, Herrera‐Gomez A, Gaskell KJ. Evolving efforts to maintain and improve XPS analysis quality in an era of increasingly diverse uses and users. SURF INTERFACE ANAL 2023. [DOI: 10.1002/sia.7194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
| | - John F. Watts
- School of Mechanical Engineering Sciences, University of Surrey Guildford Surrey UK
| | | | - Karen J. Gaskell
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD USA
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2
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Zewde B, Atoyebi O, Gugssa A, Gaskell KJ, Raghavan D. Correction to "An Investigation of the Interaction Between Bovine Serum Albumin-Conjugated Silver Nanoparticles and the Hydrogel in Hydrogel Nanocomposites". ACS Omega 2021; 6:22463-22465. [PMID: 34497937 PMCID: PMC8412953 DOI: 10.1021/acsomega.1c04071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Indexed: 06/13/2023]
Abstract
[This corrects the article DOI: 10.1021/acsomega.1c00834.].
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3
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Zewde B, Atoyebi O, Gugssa A, Gaskell KJ, Raghavan D. An Investigation of the Interaction between Bovine Serum Albumin-Conjugated Silver Nanoparticles and the Hydrogel in Hydrogel Nanocomposites. ACS Omega 2021; 6:11614-11627. [PMID: 34056317 PMCID: PMC8154021 DOI: 10.1021/acsomega.1c00834] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 02/15/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Nanocomposite hydrogels are attracting significant interest due to their potential use in drug delivery systems and tissue scaffolds. Stimuli-responsive hydrogel nanocomposites are of particular interest due to sustained release of therapeutic agents from the hydrogel. However, challenges such as controlled release of therapeutic agents exist because of limited understanding of the interactions between the therapeutic agent and the hydrogel. To investigate the interaction, we synthesize a hydrogel nanocomposite by crosslinking the hydrogel precursors (tetrazine-modified polyethylene glycol and norbornene-modified hyaluronic acid) using click chemistry while bovine serum albumin-capped silver nanoparticles were encapsulated in situ in the matrix. The interaction between the nanoparticles and the hydrogel was studied by a combination of spectroscopic techniques. X-ray photoelectron spectroscopy results suggest that the hydrogel molecule rearranges so that polyethylene glycol is pointing up toward the surface while hyaluronic acid folds to interact with bovine serum albumin of the nanoparticles. Hyaluronic acid, facing inward, may interact with the nanoparticle via hydrogen bonding. The hydrogel nanocomposite showed antibacterial activity against Gram-positive/Gram-negative bactericides, supporting time-based nanoparticle release results. Our findings about interactions between the nanoparticles and the hydrogel can be useful in the formulation of next generation of hydrogel nanocomposites.
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Affiliation(s)
- Berhanu Zewde
- Department
of Chemistry, Howard University, Washington, D.C. 20059, United States
| | - Olufolasade Atoyebi
- Department
of Chemistry, Howard University, Washington, D.C. 20059, United States
| | - Ayele Gugssa
- Department
of Biology, Howard University, Washington, D.C. 20059, United States
| | - Karen J. Gaskell
- Department
of Chemistry, University of Maryland College
Park, College Park, Maryland 20742, United
States
| | - Dharmaraj Raghavan
- Department
of Chemistry, Howard University, Washington, D.C. 20059, United States
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4
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Reed BP, Cant DJH, Spencer SJ, Carmona-Carmona AJ, Bushell A, Herrera-Gómez A, Kurokawa A, Thissen A, Thomas AG, Britton AJ, Bernasik A, Fuchs A, Baddorf AP, Bock B, Theilacker B, Cheng B, Castner DG, Morgan DJ, Valley D, Willneff EA, Smith EF, Nolot E, Xie F, Zorn G, Smith GC, Yasufuku H, Fenton JL, Chen J, Counsell JDP, Radnik J, Gaskell KJ, Artyushkova K, Yang L, Zhang L, Eguchi M, Walker M, Hajdyła M, Marzec MM, Linford MR, Kubota N, Cortazar-Martínez O, Dietrich P, Satoh R, Schroeder SLM, Avval TG, Nagatomi T, Fernandez V, Lake W, Azuma Y, Yoshikawa Y, Shard AG. Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene. J Vac Sci Technol A 2020; 38:063208. [PMID: 33281279 PMCID: PMC7688089 DOI: 10.1116/6.0000577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/30/2020] [Indexed: 06/12/2023]
Abstract
We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration.
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Affiliation(s)
- Benjamen P. Reed
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - David J. H. Cant
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - Steve J. Spencer
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | | | - Adam Bushell
- Thermo Fisher Scientific (Surface Analysis), East Grinstead RH19 1XZ, United Kingdom
| | | | - Akira Kurokawa
- National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Andreas Thissen
- SPECS Surface Nano Analysis GmbH, Voltastraße 5, 13355 Berlin, Germany
| | - Andrew G. Thomas
- School of Materials, Photon Science Institute and Sir Henry Royce Institute, Alan Turing Building, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Andrew J. Britton
- Versatile X-ray Spectroscopy Facility, School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Andrzej Bernasik
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Kraków, Poland
| | - Anne Fuchs
- Robert Bosch GmbH, Robert-Bosch-Campus, 71272 Renningen, Germany
| | - Arthur P. Baddorf
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830
| | - Bernd Bock
- Tascon GmbH, Mendelstr. 17, D-48149 Münster, Germany
| | - Bill Theilacker
- Medtronic, 710 Medtronic Parkway, LT240, Fridley, Minnesota 55432
| | - Bin Cheng
- Analysis and Testing Center, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
| | - David G. Castner
- National ESCA and Surface Analysis Center for Biomedical Problems, Department of Bioengineering and Chemical Engineering, University of Washington, Seattle, Washington 98195
| | - David J. Morgan
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Cardiff CF10 3AT, United Kingdom
| | - David Valley
- Physical Electronics Inc., East Chanhassen, Minnesota 55317
| | - Elizabeth A. Willneff
- Versatile X-ray Spectroscopy Facility, School of Design, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Emily F. Smith
- Nanoscale and Microscale Research Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | | | - Fangyan Xie
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou 510275, People’s Republic of China
| | - Gilad Zorn
- GE Research, 1 Research Circle, K1 1D7A, Niskayuna, New York 12309
| | - Graham C. Smith
- Faculty of Science and Engineering, University of Chester, Thornton Science Park, Chester CH2 4NU, United Kingdom
| | - Hideyuki Yasufuku
- Materials Analysis Station, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0044, Japan
| | - Jeffery L. Fenton
- Medtronic, 6700 Shingle Creek Parkway, Brooklyn Center, Minnesota 55430
| | - Jian Chen
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou 510275, People’s Republic of China
| | | | - Jörg Radnik
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203 Berlin, Germany
| | - Karen J. Gaskell
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | | | - Li Yang
- Department of Chemistry, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Road, Suzhou Dushu Lake Science and Education Innovation District, Suzhou Industrial Park, Suzhou 215123, People’s Republic of China
| | - Lulu Zhang
- National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Makiho Eguchi
- Analysis Department, Materials Characterization Division, Futtsu Unit, Nippon Steel Technology Co. Ltd., 20-1 Shintomi, Futtsu City, Chiba 293-0011, Japan
| | - Marc Walker
- Department of Physics, University of Warwick, Coventry, West Midlands CV4 7AL, United Kingdom
| | - Mariusz Hajdyła
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Kraków, Poland
| | - Mateusz M. Marzec
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Kraków, Poland
| | - Matthew R. Linford
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, Utah 84602
| | - Naoyoshi Kubota
- Analysis Department, Materials Characterization Division, Futtsu Unit, Nippon Steel Technology Co. Ltd., 20-1 Shintomi, Futtsu City, Chiba 293-0011, Japan
| | | | - Paul Dietrich
- SPECS Surface Nano Analysis GmbH, Voltastraße 5, 13355 Berlin, Germany
| | - Riki Satoh
- Analysis Department, Materials Characterization Division, Futtsu Unit, Nippon Steel Technology Co. Ltd., 20-1 Shintomi, Futtsu City, Chiba 293-0011, Japan
| | - Sven L. M. Schroeder
- Versatile X-ray Spectroscopy Facility, School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Tahereh G. Avval
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, Utah 84602
| | - Takaharu Nagatomi
- Platform Laboratory for Science and Technology, Asahi Kasei Corporation, 2-1 Samejima, Fuji, Shizuoka 416-8501, Japan
| | - Vincent Fernandez
- Université de Nantes, CNRS, Institut des Matériaux Jean Rouxel, IMN, F-44000 Nantes, France
| | - Wayne Lake
- Atomic Weapons Establishment (AWE), Aldermaston, Reading, Berkshire RG7 4PR, United Kingdom
| | - Yasushi Azuma
- National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Yusuke Yoshikawa
- Material Analysis Department, Yazaki Research and Technology Center, Yazaki Corporation, 1500 Mishuku, Susono-city, Shizuoka 410-1194, Japan
| | - Alexander G. Shard
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
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5
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Linford MR, Smentkowski VS, Grant JT, Brundle CR, Sherwood PMA, Biesinger MC, Terry J, Artyushkova K, Herrera-Gómez A, Tougaard S, Skinner W, Pireaux JJ, McConville CF, Easton CD, Gengenbach TR, Major GH, Dietrich P, Thissen A, Engelhard M, Powell CJ, Gaskell KJ, Baer DR. Proliferation of Faulty Materials Data Analysis in the Literature. Microsc Microanal 2020; 26:1-2. [PMID: 31948499 DOI: 10.1017/s1431927619015332] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Matthew R Linford
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT84602, USA
| | | | - John T Grant
- Surface Analysis Consultant, Clearwater, FL33767, USA
| | | | | | - Mark C Biesinger
- Surface Science Western, University of Western Ontario, London, OntarioN6G 0J3, Canada
| | - Jeff Terry
- Department of Physics, Illinois Institute of Technology, Chicago, IL60616, USA
| | | | | | - Sven Tougaard
- Department of Physics, University of Southern Denmark, Odense5230, Denmark
| | - William Skinner
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| | | | | | | | | | - George H Major
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT84602, USA
| | - Paul Dietrich
- SPECS Surface Nano Analysis GmbH, 13355Berlin, Germany
| | | | - Mark Engelhard
- Pacific Northwest National Laboratory, Richland, WA99354, USA
| | - Cedric J Powell
- National Institute of Standards and Technology, Gaithersburg, MD20899, USA
| | | | - Donald R Baer
- Pacific Northwest National Laboratory, Richland, WA99354, USA
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6
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Baer DR, Artyushkova K, Brundle CR, Castle JE, Engelhard MH, Gaskell KJ, Grant JT, Haasch RT, Linford MR, Powell CJ, Shard AG, Sherwood PMA, Smentkowski VS. Practical Guides for X-Ray Photoelectron Spectroscopy (XPS): First Steps in planning, conducting and reporting XPS measurements. J Vac Sci Technol A 2019; 37:10.1116/1.5065501. [PMID: 31579351 PMCID: PMC6774202 DOI: 10.1116/1.5065501] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Over the past three decades, the widespread utility and applicability of X-ray photoelectron spectroscopy (XPS) in research and applications has made it the most popular and widely used method of surface analysis. Associated with this increased use has been an increase in the number of new or inexperienced users which has led to erroneous uses and misapplications of the method. This article is the first in a series of guides assembled by a committee of experienced XPS practitioners that are intended to assist inexperienced users by providing information about good practices in the use of XPS. This first guide outlines steps appropriate for determining whether XPS is capable of obtaining the desired information, identifies issues relevant to planning, conducting and reporting an XPS measurement, and identifies sources of practical information for conducting XPS measurements. Many of the topics and questions addressed in this article also apply to other surface-analysis techniques.
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Affiliation(s)
- Donald R. Baer
- Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, P. O. Box 999, Richland, Washington 99352
| | | | | | - James E. Castle
- University of Surrey, Department of Mechanical Engineering Science, Guildford, Surrey, GU2 7XH, United Kingdom
| | - Mark H. Engelhard
- Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, P. O. Box 999, Richland Washington 99352
| | - Karen J. Gaskell
- University of Maryland, Department of Chemistry and Biochemistry, College Park, Maryland 20720
| | - John T. Grant
- Surface Analysis Consulting, Clearwater, Florida 33767
| | - Richard T. Haasch
- University of Illinois, Materials Research Laboratory, 104 S. Goodwin Ave, Urbana, Illinois 61801-2902
| | - Matthew R. Linford
- Brigham Young University, Department of Chemistry & Biochemistry, Provo, Utah 84602
| | - Cedric J. Powell
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8370
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7
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Zavalij PY, Stevens LM, Ponce A, Gibbons SK, Gaskell KJ, Brostoff LB, Eichhorn BW. Structural metamorphosis of the Fe(III) gallate – a historical iron gall ink. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s0108767318096265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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8
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Luo C, Ji X, Chen J, Gaskell KJ, He X, Liang Y, Jiang J, Wang C. Solid‐State Electrolyte Anchored with a Carboxylated Azo Compound for All‐Solid‐State Lithium Batteries. Angew Chem Int Ed Engl 2018; 57:8567-8571. [DOI: 10.1002/anie.201804068] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Chao Luo
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiao Ji
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
- School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei 430074 China
| | - Ji Chen
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Karen J. Gaskell
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Xinzi He
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Yujia Liang
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Jianjun Jiang
- School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei 430074 China
| | - Chunsheng Wang
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
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9
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Luo C, Ji X, Chen J, Gaskell KJ, He X, Liang Y, Jiang J, Wang C. Solid‐State Electrolyte Anchored with a Carboxylated Azo Compound for All‐Solid‐State Lithium Batteries. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804068] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Chao Luo
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiao Ji
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
- School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei 430074 China
| | - Ji Chen
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Karen J. Gaskell
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Xinzi He
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Yujia Liang
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
| | - Jianjun Jiang
- School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei 430074 China
| | - Chunsheng Wang
- Department of Chemical and Biomolecular Engineering University of Maryland College Park MD 20740 USA
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10
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Gao T, Li X, Wang X, Hu J, Han F, Fan X, Suo L, Pearse AJ, Lee SB, Rubloff GW, Gaskell KJ, Noked M, Wang C. A Rechargeable Al/S Battery with an Ionic‐Liquid Electrolyte. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603531] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tao Gao
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiaogang Li
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiwen Wang
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Junkai Hu
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Fudong Han
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiulin Fan
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Liumin Suo
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Alex J Pearse
- Department of Material Science and Engineering University of Maryland College Park MD 20740 USA
| | - Sang Bok Lee
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Gary W. Rubloff
- Department of Material Science and Engineering University of Maryland College Park MD 20740 USA
| | - Karen J Gaskell
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Malachi Noked
- Department of Material Science and Engineering University of Maryland College Park MD 20740 USA
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Chunsheng Wang
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
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11
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Gao T, Li X, Wang X, Hu J, Han F, Fan X, Suo L, Pearse AJ, Lee SB, Rubloff GW, Gaskell KJ, Noked M, Wang C. A Rechargeable Al/S Battery with an Ionic‐Liquid Electrolyte. Angew Chem Int Ed Engl 2016; 55:9898-901. [DOI: 10.1002/anie.201603531] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Tao Gao
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiaogang Li
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiwen Wang
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Junkai Hu
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Fudong Han
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Xiulin Fan
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Liumin Suo
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
| | - Alex J Pearse
- Department of Material Science and Engineering University of Maryland College Park MD 20740 USA
| | - Sang Bok Lee
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Gary W. Rubloff
- Department of Material Science and Engineering University of Maryland College Park MD 20740 USA
| | - Karen J Gaskell
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Malachi Noked
- Department of Material Science and Engineering University of Maryland College Park MD 20740 USA
- Department of Chemistry and Biochemistry University of Maryland College Park MD 20740 USA
| | - Chunsheng Wang
- Department of Chemical and Bimolecular Engineering University of Maryland College Park MD 20740 USA
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12
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Knorr DB, Tran NT, Gaskell KJ, Orlicki JA, Woicik JC, Jaye C, Fischer DA, Lenhart JL. Synthesis and Characterization of Aminopropyltriethoxysilane-Polydopamine Coatings. Langmuir 2016; 32:4370-4381. [PMID: 27055091 DOI: 10.1021/acs.langmuir.6b00531] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Polydopamine coatings are of interest due to the fact that they can promote adhesion to a broad range of materials and can enable a variety of applications. However, the polydopamine-substrate interaction is often noncovalent. To broaden the potential applications of polydopamine, we show the incorporation of 3-aminopropyltriethoxysilane (APTES), a traditional coupling agent capable of covalent bonding to a broad range of organic and inorganic surfaces, into polydopamine coatings. High energy X-ray photoelectron spectroscopy (HE-XPS), conventional XPS, near-edge X-ray absorption fine structure (NEXAFS), Fourier transform infrared-attenuated total reflectance (FTIR-ATR), and ellipsometry measurements were used to investigate changes in coating chemistry and thickness, which suggest covalent incorporation of APTES into polydopamine. These coatings can be deposited either in Tris buffer or by using an aqueous APTES solution as a buffer without Tris. APTES-dopamine hydrochloride deposition from solutions with molar ratios between 0:1 and 10:1 allowed us to control the coating composition across a broad range.
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Affiliation(s)
- Daniel B Knorr
- U.S. Army Research Laboratory , Aberdeen Proving Ground, Maryland 21005, United States
| | - Ngon T Tran
- U.S. Army Research Laboratory , Aberdeen Proving Ground, Maryland 21005, United States
| | - Karen J Gaskell
- Department of Chemistry and Biochemistry, University of Maryland College Park , College Park, Maryland 20742, United States
| | - Joshua A Orlicki
- U.S. Army Research Laboratory , Aberdeen Proving Ground, Maryland 21005, United States
| | - Joseph C Woicik
- Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Cherno Jaye
- Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Daniel A Fischer
- Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Joseph L Lenhart
- U.S. Army Research Laboratory , Aberdeen Proving Ground, Maryland 21005, United States
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13
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Ponce A, Brostoff LB, Gibbons SK, Zavalij P, Viragh C, Hooper J, Alnemrat S, Gaskell KJ, Eichhorn B. Elucidation of the Fe(III) Gallate Structure in Historical Iron Gall Ink. Anal Chem 2016; 88:5152-8. [PMID: 27058399 DOI: 10.1021/acs.analchem.6b00088] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Synthetic, structural, spectroscopic and aging studies conclusively show that the main colorant of historical iron gall ink (IGI) is an amorphous form of Fe(III) gallate·xH2O (x = ∼1.5-3.2). Comparisons between experimental samples and historical documents, including an 18th century hand-written manuscript by George Washington, by IR and Raman spectroscopy, XRD, X-ray photoelectron spectroscopy, and Mössbauer spectroscopy confirm the relationship between the model and authentic samples. These studies settle controversy in the cultural heritage field, where an alternative structure for Fe(III) gallate has been commonly cited.
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Affiliation(s)
- Aldo Ponce
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Lynn B Brostoff
- Preservation Research and Testing Division, Library of Congress , 101 Independence Avenue SE, Washington, District of Columbia 20540, United States
| | - Sarah K Gibbons
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Peter Zavalij
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Carol Viragh
- Vitreous State Laboratory (VSL), The Catholic University of America , 400 Hannan Hall, 620 Michigan Avenue NE, Washington, District of Columbia 20064, United States
| | - Joseph Hooper
- Department of Physics, Naval Postgraduate School at Monterey , Monterey, California 93943, United States
| | - Sufian Alnemrat
- Department of Physics, Naval Postgraduate School at Monterey , Monterey, California 93943, United States
| | - Karen J Gaskell
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Bryan Eichhorn
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
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14
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Abstract
A single-material battery is prepared using Li10GeP2S12 as the electrolyte, anode, and cathode, based on the Li-S and Ge-S components in Li10GeP2S12 acting as the active centers for its cathode and anode performance, respectively. The single-Li10GeP2S12 battery exhibits a remarkably low interfacial resistance due to the improvement of interfacial contact and interactions, and the suppression of interfacial strain/stress.
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Affiliation(s)
- Fudong Han
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Tao Gao
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Yujie Zhu
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Karen J Gaskell
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Chunsheng Wang
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, 20742, USA
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15
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Zewde B, Pitliya P, Gaskell KJ, Raghavan D. Structure-property relationship of substituted pyrrolidine functionalized CNT epoxy nanocomposite. J Appl Polym Sci 2015. [DOI: 10.1002/app.42284] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Berhanu Zewde
- Department of Chemistry; Howard University; Washington DC 20059
| | - Praveen Pitliya
- Department of Chemistry; Howard University; Washington DC 20059
| | - Karen J. Gaskell
- Department of Chemistry and Biochemistry; University of Maryland; College Park Maryland
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16
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Sims CM, Ponce AA, Gaskell KJ, Eichhorn BW. CO tolerance of Pt and PtSn intermetallic electrocatalysts on synthetically modified reduced graphene oxide supports. Dalton Trans 2015; 44:977-87. [DOI: 10.1039/c4dt02544j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Electrochemical studies demonstrated the ability to modify the catalytic activities of graphene supported Pt and PtSn nanoparticle electrocatalysts by altering the nature of the metal-support interactions.
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Affiliation(s)
- Christopher M. Sims
- Department of Chemistry and Biochemistry
- University of Maryland
- College Park
- USA
| | - Audaldo A. Ponce
- Department of Chemistry and Biochemistry
- University of Maryland
- College Park
- USA
| | - Karen J. Gaskell
- Department of Chemistry and Biochemistry
- University of Maryland
- College Park
- USA
| | - Bryan W. Eichhorn
- Department of Chemistry and Biochemistry
- University of Maryland
- College Park
- USA
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17
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v Cresce A, Russell SM, Baker DR, Gaskell KJ, Xu K. In situ and quantitative characterization of solid electrolyte interphases. Nano Lett 2014; 14:1405-1412. [PMID: 24475938 DOI: 10.1021/nl404471v] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Despite its importance in dictating electrochemical reversibility and cell chemistry kinetics, the solid electrolyte interphase (SEI) on graphitic anodes remains the least understood component in Li ion batteries due to its trace presence, delicate chemical nature, heterogeneity in morphology, elusive formation mechanism, and lack of reliable in situ quantitative tools to characterize it. This work summarizes our systematic approach to understand SEI live formation, via in situ electrochemical atomic force microscopy, which provides topographic images and quantitative information about the structure, hierarchy, and thickness of interphases as function of electrolyte composition. Complemented by an ex situ chemical analysis, a comprehensive and dynamic picture of interphase formation during the first lithiation cycle of the graphitic anode is described. This combined approach provides an in situ and quantitative tool to conduct quality control of formed interphases.
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Affiliation(s)
- Arthur v Cresce
- Electrochemistry Branch, Power and Energy Division, Sensor and Electron Devices Directorate, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States
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18
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Han X, Liu Y, Jia Z, Chen YC, Wan J, Weadock N, Gaskell KJ, Li T, Hu L. Atomic-layer-deposition oxide nanoglue for sodium ion batteries. Nano Lett 2014; 14:139-147. [PMID: 24283393 DOI: 10.1021/nl4035626] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Atomic-layer-deposition (ALD) coatings have been increasingly used to improve battery performance. However, the electrochemical and mechanistic roles remain largely unclear, especially for ALD coatings on electrodes that undergo significant volume changes (up to 100%) during charging/discharging. Here we investigate an anode consisting of tin nanoparticles (SnNPs) with an ALD-Al2O3 coating. For the first time, in situ transmission electron microscopy unveiled the dynamic mechanical protection of the ALD-Al2O3 coating by coherently deforming with the SnNPs under the huge volume changes during charging/discharging. Battery tests in coin-cells further showed the ALD-Al2O3 coating remarkably boosts the cycling performance of the Sn anodes, comparing with those made of bare SnNPs. Chemomechanical simulations clearly revealed that a bare SnNP debonds and falls off the underlying substrate upon charging, and by contrast the ALD-Al2O3 coating, like ion-conductive nanoglue, robustly anchors the SnNP anode to the substrate during charging/discharging, a key to improving battery cycle performance.
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Affiliation(s)
- Xiaogang Han
- Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States
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19
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Zhang C, Grass ME, Yu Y, Gaskell KJ, DeCaluwe SC, Chang R, Jackson GS, Hussain Z, Bluhm H, Eichhorn BW, Liu Z. Multielement Activity Mapping and Potential Mapping in Solid Oxide Electrochemical Cells through the use of operando XPS. ACS Catal 2012. [DOI: 10.1021/cs3004243] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chunjuan Zhang
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Michael E. Grass
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Yi Yu
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Karen J. Gaskell
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Steven C. DeCaluwe
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Rui Chang
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Gregory S. Jackson
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Zahid Hussain
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Hendrik Bluhm
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Bryan W. Eichhorn
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
| | - Zhi Liu
- Department
of Chemistry and Biochemistry and §Department of Mechanical Engineering, University of Maryland, College Park,
Maryland 20742, United States
- Advanced
Light Source and ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
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20
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Brozena AH, Moskowitz J, Shao B, Deng S, Liao H, Gaskell KJ, Wang Y. Outer Wall Selectively Oxidized, Water-Soluble Double-Walled Carbon Nanotubes. J Am Chem Soc 2010; 132:3932-8. [DOI: 10.1021/ja910626u] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexandra H. Brozena
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
| | - Jessica Moskowitz
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
| | - Beiyue Shao
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
| | - Shunliu Deng
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
| | - Hongwei Liao
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
| | - Karen J. Gaskell
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
| | - YuHuang Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, Department of Chemistry, Xiamen University, Xiamen, Fujian, China, and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742
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21
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Pati RK, Lee IC, Hou S, Akhuemonkhan O, Gaskell KJ, Wang Q, Frenkel AI, Chu D, Salamanca-Riba LG, Ehrman SH. Flame synthesis of nanosized Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O catalysts for the water-gas shift (WGS) reaction. ACS Appl Mater Interfaces 2009; 1:2624-2635. [PMID: 20356136 DOI: 10.1021/am900533p] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A flame synthesis method has been used to prepare nanosized, high-surface-area Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O catalysts from aqueous solutions of metal acetate precursors. The particles were formed by vaporization of the precursors followed by reaction and then gas to particle conversion. The specific surface areas of the synthesized powders ranged from 127 to 163 m(2)/g. High-resolution transmission electron microscope imaging showed that the particle diameters for the ceria materials are in the range of 3-10 nm, and a thin layer of amorphous material was observed on the surface of the particles. The presence and surface enrichment of the transition-metal oxides (CuO, NiO, and Fe(2)O(3)) on the ceria particles were detected using X-ray photoelectron spectroscopy. Electron energy-loss spectroscopic studies suggest the formation of a core-shell structure in the as-prepared particles. Extended X-ray absorption fine structure studies suggest that the dopants in all M-Ce-O systems are almost isostructural with their oxide counterparts, indicating the doping materials form separate oxide phases (CuO, Fe(2)O(3), NiO) within the host matrix (CeO(2)). Etching results confirm that most of the transition-metal oxides are present on the surface of CeO(2), easily dissolved by nitric acid. The performance of the flame-synthesized catalysts was examined toward water-gas shift (WGS) activity for fuel processing applications. The WGS activity of metal ceria catalysts decreases in the order Cu-Ce-O > Ni-Ce-O > Fe-Ce-O > CeO(2) with a feed mixture having a hydrogen to carbon monoxide (H(2)/CO) ratio of 1. There was no methane formation for these catalysts under the tested conditions.
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Affiliation(s)
- Ranjan K Pati
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, USA
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22
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Abstract
Synthesis of cerium oxide nanocrystallites via precipitation using triethanolamine is reported. The molecular water associated with the cerium nitrate precursor is exploited to generate hydroxyl ions with the help of triethanolamine, facilitating precipitation. The small crystallite diameter (3 nm) in the as prepared powder is believed to result from the limited amount of water present. Solvent type has no effect on the final crystallite size or structure; however, it plays an important role in the dispersion of the nanoparticles with dispersity of the particles increasing with increasing carbon chain length of the solvent alcohol used.
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Affiliation(s)
- Ranjan K Pati
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, USA
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23
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Li L, Driscoll M, Kumi G, Hernandez R, Gaskell KJ, Losert W, Fourkas JT. Binary and gray-scale patterning of chemical functionality on polymer films. J Am Chem Soc 2008; 130:13512-3. [PMID: 18800792 DOI: 10.1021/ja803999r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a facile technique for the gray-scale chemical functionalization of polymer surfaces with high dynamic range. We demonstrate the use of this technique to create amine-functionalized substrates that are used for the patterned binding of fluorophores and the patterned synthesis of peptides. Studies of the behavior of the model organism Dictyostelium discoideum indicate the biocompatibility of the functionalized substrates.
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Affiliation(s)
- Linjie Li
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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24
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Liu Y, Gaskell KJ, Cheng Z, Yu LL, Payne GF. Chitosan-coated electrodes for bimodal sensing: selective post-electrode film reaction for spectroelectrochemical analysis. Langmuir 2008; 24:7223-7231. [PMID: 18547081 DOI: 10.1021/la800180y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Electrochemical methods are well suited for chemical detection in hand-held devices because they are simple, fast, and sensitive. However, electrochemical detection methods generally suffer from limitations in selectivity. We report a novel approach that enables electrochemically initiated reactions to generate optical signals that can be used to enhance the discriminating power for the electrochemical analysis of antioxidant food phenols. This spectroelectrochemical approach employs transparent electrodes coated with a film of the aminopolysaccharide chitosan. The phenolic analytes diffuse through the chitosan film to the electrode where they are anodically oxidized into electrophilic intermediates that undergo postelectrode reactions with the chitosan film. The postelectrode reaction was analyzed by FTIR and XPS, and this reaction was observed to impart optical properties (color and UV-visible absorbance) to the otherwise colorless and transparent chitosan film. We demonstrate that the optical signal generated from the postelectrode film reaction is selective for oxidized phenols, compared to that for unoxidized phenols or the nonphenolic antioxidant ascorbic acid. Furthermore, we demonstrate that the optical signal (film absorbance) can be correlated to the electrical signal (charge transferred). Finally, we use simple mixtures to demonstrate that the coupling of information from independent optical and electrical measurement modes can assist in the qualitative analysis of antioxidant phenols. Potentially, the postelectrode film reaction may provide a selective and reagentless alternative to conventional colorimetric methods for detecting antioxidant phenols. In a broader perspective, this work suggests the potential for coupling independent detection modes (optical and electrical) to enhance the information content of sensor measurements.
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Affiliation(s)
- Yi Liu
- Center for Biosystems Research, University of Maryland Biotechnology Institute, 5115 Plant Sciences Building, College Park, Maryland 20742, USA
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25
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Kadossov EB, Gaskell KJ, Langell MA. Effect of surrounding point charges on the density functional calculations of NixOx clusters (x = 4–12). J Comput Chem 2007; 28:1240-51. [PMID: 17299835 DOI: 10.1002/jcc.20669] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Embedded Ni(x)O(x) clusters (x = 4-12) have been studied by the density-functional method using compensating point charges of variable magnitude to calculate the ionic charge, bulk modulus, and lattice binding energy. The computations were found to be strongly dependent on the value of the surrounding point charge array and an optimum value could be found by choosing the point charge to reproduce the experimentally observed Ni--O lattice parameter. This simple, empirical method yields a good match between computed and experimental data, and even small variation from the optimum point charge value produces significant deviation between computed and measured bulk physical parameters. The optimum point charge value depends on the cluster size, but in all cases is significantly less than +/-2.0, the formal oxidation state typically employed in cluster modeling of NiO bulk and surface properties. The electronic structure calculated with the optimized point charge magnitude is in general agreement with literature photoemission and XPS data and agrees with the presently accepted picture of the valence band as containing charge-transfer insulator characteristics. The orbital population near the Fermi level does not depend on the cluster size and is characterized by hybridized Ni 3d and O 2p orbitals with relative oxygen contribution of about 70%.
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Affiliation(s)
- Evgueni B Kadossov
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
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