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Gutiérrez-Gálvez L, García-Mendiola T, Lorenzo E, Nuez-Martinez M, Ocal C, Yan S, Teixidor F, Pinheiro T, Marques F, Viñas C. Compelling DNA intercalation through 'anion-anion' anti-coulombic interactions: boron cluster self-vehicles as promising anticancer agents. J Mater Chem B 2024. [PMID: 39141010 DOI: 10.1039/d4tb01177e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Anticancer drugs inhibit DNA replication by intercalating between DNA base pairs, forming covalent bonds with nucleotide bases, or binding to the DNA groove. To develop safer drugs, novel molecular structures with alternative binding mechanisms are essential. Stable boron hydrides offer a promising alternative for cancer therapy, opening up additional options like boron neutron capture therapy based on 10B and thermal neutron beams or proton boron fusion therapy using 11B and proton beams. These therapies are more efficient when the boron compound is ideally located inside cancer cells, particularly in the nucleus. Current cancer treatments often utilize small, polycyclic, aromatic, planar molecules that intercalate between ds-DNA base pairs, requiring only a spacing of approximately 0.34 nm. In this paper, we demonstrate another type of intercalation. Notably, [3,3'-Fe(1,2-C2B9H11)2]-, ([o-FESAN]-), a compact 3D molecule measuring 1.1 nm × 0.6 nm, can as well intercalate by strong non-bonding interactions preferentially with guanine. Unlike known intercalators, which are positive or neutral, [o-FESAN]- is a negative species and when an [o-FESAN]- molecule approaches the negatively charged DNA phosphate chain an anion-anion interaction consistently anti-electrostatic via Ccluster-H⋯O-P bonds occurs. Then, when more molecules approach, an elongated outstandingly self-assembled structure of [o-FESAN]--[o-FESAN]- forms moving anions towards the interthread region to interact with base pairs and form aggregates of four [o-FESAN]- anions per base pair. These aggregates, in this environment, are generated by Ccluster-H⋯O-C, N-H⋯H-B and Ccluster-H⋯H-B interactions. The ferrabis(dicarbollide) boron-rich small molecules not only effectively penetrate the nucleus but also intercalate with ds-DNA, making them promising for cancer treatment. This amphiphilic anionic molecule, used as a carrier-free drug, can enhance radiotherapy in a multimodal perspective, providing healthcare professionals with improved tools for cancer treatment. This work demonstrates these findings with a plethora of techniques.
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Affiliation(s)
- Laura Gutiérrez-Gálvez
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Tania García-Mendiola
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Encarnación Lorenzo
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049, Madrid, Spain
- IMDEA-Nanociencia, Ciudad Universitaria de Cantoblanco, 28049, Madrid, Spain
| | - Miquel Nuez-Martinez
- Institut de Ciència de Materials de Barcelona (C.S.I.C.) Campus U.A.B, 08193 Bellaterra, Barcelona, Spain.
| | - Carmen Ocal
- Institut de Ciència de Materials de Barcelona (C.S.I.C.) Campus U.A.B, 08193 Bellaterra, Barcelona, Spain.
| | - Shunya Yan
- Institut de Ciència de Materials de Barcelona (C.S.I.C.) Campus U.A.B, 08193 Bellaterra, Barcelona, Spain.
| | - Francesc Teixidor
- Institut de Ciència de Materials de Barcelona (C.S.I.C.) Campus U.A.B, 08193 Bellaterra, Barcelona, Spain.
| | - Teresa Pinheiro
- iBB - Instituto de Bioengenharia e Biociências, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
- Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS, Portugal
| | - Fernanda Marques
- Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS, Portugal
- C2TN - Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS, Portugal
| | - Clara Viñas
- Institut de Ciència de Materials de Barcelona (C.S.I.C.) Campus U.A.B, 08193 Bellaterra, Barcelona, Spain.
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2
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Wood J, Palms D, Dabare R, Vasilev K, Bright R. Exploring the Challenges of Characterising Surface Topography of Polymer-Nanoparticle Composites. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1275. [PMID: 39120379 PMCID: PMC11313880 DOI: 10.3390/nano14151275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/25/2024] [Accepted: 07/28/2024] [Indexed: 08/10/2024]
Abstract
Nanomechanical testing plays a crucial role in evaluating surfaces containing nanoparticles. Testing verifies surface performance concerning their intended function and detects any potential shortcomings in operational standards. Recognising that nanostructured surfaces are not always straightforward or uniform is essential. The chemical composition and morphology of these surfaces determine the end-point functionality. This can entail a layered surface using materials in contrast to each other that may require further modification after nanomechanical testing to pass performance and quality standards. Nanomechanical analysis of a structured surface consisting of a poly-methyl oxazoline film base functionalised with colloidal gold nanoparticles was demonstrated using an atomic force microscope (AFM). AFM nanomechanical testing investigated the overall substrate architecture's topographical, friction, adhesion, and wear parameters. Limitations towards its potential operation as a biomaterial were also addressed. This was demonstrated by using the AFM cantilever to apply various forces and break the bonds between the polymer film and gold nanoparticles. The AFM instrument offers an insight to the behaviour of low-modulus surface against a higher-modulus nanoparticle. This paper details the bonding and reaction limitations between these materials on the application of an externally applied force. The application of this interaction is highly scrutinised to highlight the potential limitations of a functionalised surface. These findings highlight the importance of conducting comprehensive nanomechanical testing to address concerns related to fabricating intricate biomaterial surfaces featuring nanostructures.
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Affiliation(s)
- Jonathan Wood
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, SA 5095, Australia; (J.W.); (R.D.)
| | - Dennis Palms
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
| | - Ruvini Dabare
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, SA 5095, Australia; (J.W.); (R.D.)
| | - Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
| | - Richard Bright
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
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3
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Siles Brügge O, Hunter CA, Leggett GJ. Transcending Lifshitz Theory: Reliable Prediction of Adhesion Forces between Hydrocarbon Surfaces in Condensed Phases Using Molecular Contact Thermodynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:13753-13762. [PMID: 38934482 PMCID: PMC11238592 DOI: 10.1021/acs.langmuir.3c03218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Lifshitz theory is widely used to calculate interfacial interaction energies and underpins established approaches to the interpretation of measurement data from experimental methods including the surface forces apparatus and the atomic force microscope. However, a significant limitation of Lifshitz theory is that it uses the bulk dielectric properties of the medium to predict the work of adhesion. Here, we demonstrate that a different approach, in which the interactions between molecules at surfaces and in the medium are described by a set of surface site interaction points (SSIPs), yields interaction free energies that are correlated better with experimentally determined values. The work of adhesion W(Lifshitz) between hydrocarbon surfaces was calculated in 260 liquids using Lifshitz theory and compared with interaction free energies ΔΔG calculated using the SSIP model. The predictions of these models diverge in significant ways. In particular, ΔΔG values for hydrocarbon surfaces are typically small and vary little, but in contrast, W(Lifshitz) values span 4 orders of magnitude. Moreover, the SSIP model yields significantly different ΔΔG values in some liquids for which Lifshitz theory predicts similar values of W(Lifshitz). These divergent predictions were tested using atomic force microscopy. Experimentally determined works of adhesion were closer to the values predicted using the SSIP model than Lifshitz theory. In mixtures of methanol and benzyl alcohol, even greater differences were found in the interaction energies calculated using the two models: the value of ΔΔG calculated using the SSIP model declines smoothly as the benzyl alcohol concentration increases, and values are well correlated with experimental data; however, W(Lifshitz) decreases to a minimum and then increases, reaching a larger value for benzyl alcohol than for methanol. We conclude that the SSIP model provides more reliable estimates of the work of adhesion than Lifshitz theory.
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Affiliation(s)
- Oscar Siles Brügge
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
| | - Christopher A Hunter
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Graham J Leggett
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
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4
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Wu Z, Li X, Peng D, Zheng Q. Positive-Negative Tunable Coefficients of Friction in Superlubric Contacts. PHYSICAL REVIEW LETTERS 2024; 132:156201. [PMID: 38683007 DOI: 10.1103/physrevlett.132.156201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/13/2024] [Indexed: 05/01/2024]
Abstract
In conventional systems, the coefficient of friction (COF) is typically positive, signifying a direct relationship between frictional and normal forces. Contrary to this, we observe that the load dependence of friction exhibits a unique bell-shaped curve when studying the frictional properties between graphite and α-Al_{2}O_{3} surfaces. As the applied normal force increases, the friction initially rises and then decreases. Finite element simulations reveal this behavior is due to edge detachment at the graphite/α-Al_{2}O_{3} interface as the normal force approaches a critical value. Because friction in superlubric contacts predominantly arises from edges, their detachment leads to a decrease in overall friction. We empirically validate these findings by varying the radii of curvature of the tips and the thicknesses of graphite flakes. This unprecedented observation offers a new paradigm for tuning COF in superlubric applications, enabling transitions from positive to negative values.
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Affiliation(s)
- Zhanghui Wu
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Xuanhe Li
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Deli Peng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Center of Double Helix, Tsinghua Shenzhen International Graduate School, Shenzhen 518057, China
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5
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Cho S, Gaponenko I, Cordero-Edwards K, Barceló-Mercader J, Arias I, Kim D, Lichtensteiger C, Yeom J, Musy L, Kim H, Han SM, Catalan G, Paruch P, Hong S. Switchable tribology of ferroelectrics. Nat Commun 2024; 15:387. [PMID: 38195614 PMCID: PMC10776724 DOI: 10.1038/s41467-023-44346-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 12/09/2023] [Indexed: 01/11/2024] Open
Abstract
Switchable tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe-down domains have lower friction coefficients and show slower wear rates than up domains and can be used as smart masks. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force. Moreover, we determine that this polarization-sensitive tribological asymmetry is widely applicable across various ferroelectrics with different chemical compositions and crystalline symmetry. Finally, using this switchable tribology and multi-pass patterning with a domain-based dynamic smart mask, we demonstrate three-dimensional nanostructuring exploiting the asymmetric wear rates of up and down domains, which can, furthermore, be scaled up to technologically relevant (mm-cm) size. These findings demonstrate that ferroelectrics are electrically tunable tribological materials at the nanoscale for versatile applications.
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Affiliation(s)
- Seongwoo Cho
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
- Department of Quantum Matter Physics, University of Geneva, 1211, Geneva, Switzerland.
| | - Iaroslav Gaponenko
- Department of Quantum Matter Physics, University of Geneva, 1211, Geneva, Switzerland
- G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, United States of America
| | | | - Jordi Barceló-Mercader
- LaCàN - Mathematical and Computational Modeling, Polytechnic University of Catalonia, Barcelona, 08034, Spain
| | - Irene Arias
- LaCàN - Mathematical and Computational Modeling, Polytechnic University of Catalonia, Barcelona, 08034, Spain
- International Centre for Numerical Methods in Engineering (CIMNE), Barcelona, 08034, Spain
| | - Daeho Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Céline Lichtensteiger
- Department of Quantum Matter Physics, University of Geneva, 1211, Geneva, Switzerland
| | - Jiwon Yeom
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Loïc Musy
- Department of Quantum Matter Physics, University of Geneva, 1211, Geneva, Switzerland
| | - Hyunji Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Seung Min Han
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Gustau Catalan
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), Campus Autonomous University of Barcelona, Bellaterra, 08193, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, 08010, Catalonia
| | - Patrycja Paruch
- Department of Quantum Matter Physics, University of Geneva, 1211, Geneva, Switzerland.
| | - Seungbum Hong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
- KAIST Institute for NanoCentury (KINC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
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6
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Lee D, Jeong H, Lee H, Kim YH, Park JY. Phase-dependent Friction on Exfoliated Transition Metal Dichalcogenides Atomic Layers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302713. [PMID: 37485739 DOI: 10.1002/smll.202302713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/07/2023] [Indexed: 07/25/2023]
Abstract
The fundamental aspects of energy dissipation on 2-dimensional (2D) atomic layers are extensively studied. Among various atomic layers, transition metal dichalcogenides (TMDs) exists in several phases based on their lattice structure, which give rise to the different phononic and electronic contributions in energy dissipation. 2H and 1T' (distorted 1T) phase MoS2 and MoTe2 atomic layers exfoliated on mica substrate are obtained and investigated their nanotribological properties with atomic force microscopy (AFM)/ friction force microscopy (FFM). Surprisingly, 1T' phase of both MoS2 and MoTe2 exhibits ≈10 times higher friction compared to 2H phase. With density functional theory analyses, the friction increase is attributed to enhanced electronic excitation, efficient phonon dissipation, and increased potential energy surface barrier at the tip-sample interface. This study suggests the intriguing possibility of tuning the friction of TMDs through phase transition, which can lead to potential application in tunable tribological devices.
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Affiliation(s)
- Dooho Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hochan Jeong
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hyunsoo Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yong-Hyun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jeong Young Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
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7
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Greenwood G, Kim JM, Nahid SM, Lee Y, Hajarian A, Nam S, Espinosa-Marzal RM. Dynamically tuning friction at the graphene interface using the field effect. Nat Commun 2023; 14:5801. [PMID: 37726306 PMCID: PMC10509204 DOI: 10.1038/s41467-023-41375-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 09/01/2023] [Indexed: 09/21/2023] Open
Abstract
Dynamically controlling friction in micro- and nanoscale devices is possible using applied electrical bias between contacting surfaces, but this can also induce unwanted reactions which can affect device performance. External electric fields provide a way around this limitation by removing the need to apply bias directly between the contacting surfaces. 2D materials are promising candidates for this approach as their properties can be easily tuned by electric fields and they can be straightforwardly used as surface coatings. This work investigates the friction between single layer graphene and an atomic force microscope tip under the influence of external electric fields. While the primary effect in most systems is electrostatically controllable adhesion, graphene in contact with semiconducting tips exhibits a regime of unexpectedly enhanced and highly tunable friction. The origins of this phenomenon are discussed in the context of fundamental frictional dissipation mechanisms considering stick slip behavior, electron-phonon coupling and viscous electronic flow.
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Affiliation(s)
- Gus Greenwood
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jin Myung Kim
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - Shahriar Muhammad Nahid
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yeageun Lee
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Amin Hajarian
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - SungWoo Nam
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - Rosa M Espinosa-Marzal
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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8
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Le T, Chiang Y, Hui Y, Le T, Tzeng Y, Sharma N, Chiang W, Hsiao W. In vitroBioimaging of Fluorescent Nanodiamonds. NANODIAMONDS IN ANALYTICAL AND BIOLOGICAL SCIENCES 2023:95-127. [DOI: 10.1002/9781394202164.ch6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
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9
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Turnbull IC, Bajpai A, Jankowski KB, Gaitas A. Single-Cell Analysis of Contractile Forces in iPSC-Derived Cardiomyocytes: Paving the Way for Precision Medicine in Cardiovascular Disease. Int J Mol Sci 2023; 24:13416. [PMID: 37686223 PMCID: PMC10487756 DOI: 10.3390/ijms241713416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) hold enormous potential in cardiac disease modeling, drug screening, and regenerative medicine. Furthermore, patient-specific iPSC-CMS can be tested for personalized medicine. To provide a deeper understanding of the contractile force dynamics of iPSC-CMs, we employed Atomic Force Microscopy (AFM) as an advanced detection tool to distinguish the characteristics of force dynamics at a single cell level. We measured normal (vertical) and lateral (axial) force at different pacing frequencies. We found a significant correlation between normal and lateral force. We also observed a significant force-frequency relationship for both types of forces. This work represents the first demonstration of the correlation of normal and lateral force from individual iPSC-CMs. The identification of this correlation is relevant because it validates the comparison across systems and models that can only account for either normal or lateral force. These findings enhance our understanding of iPSC-CM properties, thereby paving the way for the development of therapeutic strategies in cardiovascular medicine.
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Affiliation(s)
- Irene C. Turnbull
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Apratim Bajpai
- The Estelle and Daniel Maggin Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Katherine B. Jankowski
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Angelo Gaitas
- The Estelle and Daniel Maggin Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- BioMedical Engineering & Imaging Institute, Leon and Norma Hess Center for Science and Medicine, New York, NY 10029, USA
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10
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Johnson EC, Varlas S, Norvilaite O, Neal TJ, Brotherton EE, Sanderson G, Leggett GJ, Armes SP. Adsorption of Aldehyde-Functional Diblock Copolymer Spheres onto Surface-Grafted Polymer Brushes via Dynamic Covalent Chemistry Enables Friction Modification. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:6109-6122. [PMID: 37576584 PMCID: PMC10413866 DOI: 10.1021/acs.chemmater.3c01227] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/05/2023] [Indexed: 08/15/2023]
Abstract
Dynamic covalent chemistry has been exploited to prepare numerous examples of adaptable polymeric materials that exhibit unique properties. Herein, the chemical adsorption of aldehyde-functional diblock copolymer spherical nanoparticles onto amine-functionalized surface-grafted polymer brushes via dynamic Schiff base chemistry is demonstrated. Initially, a series of cis-diol-functional sterically-stabilized spheres of 30-250 nm diameter were prepared via reversible addition-fragmentation chain transfer (RAFT) aqueous dispersion polymerization. The pendent cis-diol groups within the steric stabilizer chains of these precursor nanoparticles were then oxidized using sodium periodate to produce the corresponding aldehyde-functional spheres. Similarly, hydrophilic cis-diol-functionalized methacrylic brushes grafted from a planar silicon surface using activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) were selectively oxidized to generate the corresponding aldehyde-functional brushes. Ellipsometry and X-ray photoelectron spectroscopy were used to confirm brush oxidation, while scanning electron microscopy studies demonstrated that the nanoparticles did not adsorb onto a cis-diol-functional precursor brush. Subsequently, the aldehyde-functional brushes were treated with excess small-molecule diamine, and the resulting imine linkages were converted into secondary amine bonds via reductive amination. The resulting primary amine-functionalized brushes formed multiple dynamic imine bonds with the aldehyde-functional diblock copolymer spheres, leading to a mean surface coverage of approximately 0.33 on the upper brush layer surface, regardless of the nanoparticle size. Friction force microscopy studies of the resulting nanoparticle-decorated brushes enabled calculation of friction coefficients, which were compared to that measured for the bare aldehyde-functional brush. Friction coefficients were reasonably consistent across all surfaces except when particle size was comparable to the size of the probe tip. In this case, differences were ascribed to an increase in contact area between the tip and the brush-nanoparticle layer. This new model system enhances our understanding of nanoparticle adsorption onto hydrophilic brush layers.
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Affiliation(s)
- Edwin C. Johnson
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
| | - Spyridon Varlas
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
| | - Oleta Norvilaite
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
| | - Thomas J. Neal
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
| | - Emma E. Brotherton
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
| | | | - Graham J. Leggett
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
| | - Steven P. Armes
- Department
of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, U.K.
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11
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Liamas E, Connell SD, Sarkar A. Frictional behaviour of plant proteins in soft contacts: unveiling nanoscale mechanisms. NANOSCALE ADVANCES 2023; 5:1102-1114. [PMID: 36798497 PMCID: PMC9926882 DOI: 10.1039/d2na00696k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 12/26/2022] [Indexed: 06/18/2023]
Abstract
Despite the significance of nanotribology in the design of functional biomaterials, little is known about nanoscale friction in the presence of protein-coated soft contact surfaces. Here, we report a detailed investigation of frictional behaviour of sustainable plant proteins at the nanoscale for the first time, using deformable bio-relevant surfaces that achieve biologically relevant contact pressures. A combination of atomic force microscopy, quartz crystal microbalance with dissipation monitoring, and friction force microscopy with soft polydimethylsiloxane (PDMS, 150 kPa) surfaces was employed to elucidate the frictional properties of model plant proteins, i.e. lupine, pea, and potato proteins at the nanoscale while systematically varying the pH and ionic strength. Interactions of these plant proteins with purified mucins were also probed. We provide the much-needed direct experimental evidence that the main factor dictating the frictional properties of plant proteins is their affinity towards the surface, followed by the degree of protein film hydration. Proteins with high surface affinity, such as pea and potato protein, have better lubricating performance than lupine at the nanoscale. Other minor factors that drive lubrication are surface interactions between sliding bodies, especially at low load, whilst jamming of the contact area caused by larger protein aggregates increases friction. Novel findings reveal that interactions between plant proteins and mucins lead to superior lubricating properties, by combining high surface affinity from the plant proteins and high hydration by mucins. We anticipate that fundamental understanding gained from this work will set the stage for the design of a plethora of sustainable biomaterials and food with optimum nanolubrication performance.
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Affiliation(s)
- Evangelos Liamas
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds UK
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds UK
| | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds UK
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12
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Panse KS, Wu H, Zhou S, Zhao F, Aluru NR, Zhang Y. Innermost Ion Association Configuration Is a Key Structural Descriptor of Ionic Liquids at Electrified Interfaces. J Phys Chem Lett 2022; 13:9464-9472. [PMID: 36198103 DOI: 10.1021/acs.jpclett.2c02768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The structure of electric double layers (EDLs) is crucial for all types of electrochemical processes. While in dilute solutions EDL structure can be approximately treated within the Gouy-Chapman-Stern regime, in highly ionic electrolytes the description of EDL has been largely elusive. Here we study the EDL structure of an ionic liquid on a series of crystalline electrodes. Through molecular dynamics (MD) simulations, we observe strong intermolecular interaction among cations and anions and propose that the cation-anion association structure at the innermost layer is a key descriptor of the EDL. Using our recently developed electrochemical 3D atomic force microscopy (EC-3D-AFM) technique, we confirm the theoretical prediction and further find that the width of the first EDL is an experimental gauge of the ion association structure in that layer. We expect such ion association descriptors to be broadly applicable to a large range of highly ionic electrolytes on various electrode surfaces.
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Affiliation(s)
- Kaustubh S Panse
- Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois61801, United States
- Materials Research Laboratory, University of Illinois, Urbana, Illinois61801, United States
| | - Haiyi Wu
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas78712, United States
- Oden Institute for Computational Engineering & Sciences, The University of Texas at Austin, Austin, Texas78712, United States
| | - Shan Zhou
- Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois61801, United States
- Materials Research Laboratory, University of Illinois, Urbana, Illinois61801, United States
| | - Fujia Zhao
- Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois61801, United States
- Materials Research Laboratory, University of Illinois, Urbana, Illinois61801, United States
| | - Narayana R Aluru
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas78712, United States
- Oden Institute for Computational Engineering & Sciences, The University of Texas at Austin, Austin, Texas78712, United States
| | - Yingjie Zhang
- Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois61801, United States
- Materials Research Laboratory, University of Illinois, Urbana, Illinois61801, United States
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13
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Milne ZB, Hasz K, McClimon JB, Castro J, Carpick RW. A modified multibond model for nanoscale static friction. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210342. [PMID: 35909363 DOI: 10.1098/rsta.2021.0342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/28/2022] [Indexed: 06/15/2023]
Abstract
Several key features of nanoscale friction phenomena observed in experiments, including the stick-slip to smooth sliding transition and the velocity and temperature dependence of friction, are often described by reduced-order models. The most notable of these are the thermal Prandtl-Tomlinson model and the multibond model. Here we present a modified multibond (mMB) model whereby a physically-based criterion-a critical bond stretch length-is used to describe interfacial bond breaking. The model explicitly incorporates damping in both the cantilever and the contacting materials. Comparison to the Fokker-Planck formalism supports the results of this new model, confirming its ability to capture the relevant physics. Furthermore, the mMB model replicates the near-logarithmic trend of increasing friction with lateral scanning speed seen in many experiments. The model can also be used to probe both correlated and uncorrelated stick slip. Through greater understanding of the effects of damping and noise in the system and the ability to more accurately simulate a system with multiple interaction sites, this model extends the range of frictional systems and phenomena that can be investigated. This article is part of the theme issue 'Nanocracks in nature and industry'.
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Affiliation(s)
- Zachary B Milne
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA, USA
| | - Kathryn Hasz
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - J B McClimon
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA, USA
| | - Juan Castro
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert W Carpick
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA, USA
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14
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Go TW, Lee H, Lee H, Song HC, Park JY. Direct Observation of Atomic-Scale Gliding on Hydrophilic Surfaces. J Phys Chem Lett 2022; 13:6612-6618. [PMID: 35834560 DOI: 10.1021/acs.jpclett.2c01895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanoscale friction behavior on hydrophilic surfaces (HS), influenced by a probe gliding on a confined water layer, has been investigated with friction force microscopy under various relative humidity (RH) conditions. The topographical and frictional responses of the mechanically exfoliated single-layer graphene (SLG) on native-oxide-covered silicon (SiO2/Si) and mica were both influenced by RH conditions. The ordinary phenomena at ambient conditions (i.e., higher friction on a HS than on a SLG due to different hydrophilicity), nondistinguishable height, friction of SLG with SiO2/Si at high RH (>98%), and the superlubricating behavior of friction on a HS were observed. Furthermore, the subdomain within SLG, consisting of an ice-like water layer intercalated between SLG and SiO2/Si, showed friction enhancement. These results suggest that the abundant water molecules at the interface of the probe and a HS can make a slippery surface that overcomes capillary and viscosity effects through the gliding motion of the probe.
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Affiliation(s)
- Tae Won Go
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Hyunsoo Lee
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Hyunhwa Lee
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Hee Chan Song
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Jeong Young Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
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15
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Yin Y, Shi L, Zhang S, Duan X, Zhang J, Sun H, Wang S. Two−dimensional nanomaterials confined single atoms: New opportunities for environmental remediation. NANO MATERIALS SCIENCE 2022. [DOI: 10.1016/j.nanoms.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Zhang S, Yao Q, Chen L, Jiang C, Ma T, Wang H, Feng XQ, Li Q. Dual-Scale Stick-Slip Friction on Graphene/h-BN Moiré Superlattice Structure. PHYSICAL REVIEW LETTERS 2022; 128:226101. [PMID: 35714257 DOI: 10.1103/physrevlett.128.226101] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/22/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Using atomic force microscopy, we have shown that friction on graphene/h-BN superlattice structures may exhibit unusual moiré-scale stick slip in addition to the regular ones observed at the atomic scale. Such dual-scale slip instability will lead to unique length-scale dependent energy dissipation when the different slip mechanisms are sequentially activated. Assisted by an improved theoretical model and comparative experiments, we find that accumulation and unstable release of the in-plane strain of the graphene layer is the key mechanism underlying the moiré-scale behavior. This work highlights the distinct role of the internal state of the van der Waals interfaces in determining the rich dynamics and energy dissipation of layer-structured materials.
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Affiliation(s)
- Shuai Zhang
- Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Quanzhou Yao
- Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Lingxiu Chen
- School of Materials Science and Physics, China University of Mining and Technology, Xuzhou 221116, China
| | - Chengxin Jiang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Tianbao Ma
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Haomin Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Xi-Qiao Feng
- Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Qunyang Li
- Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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17
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Abstract
I review experimental developments in the growth and application of surface-grafted weak polyelectrolytes (brushes), concentrating on their surface, tribological, and adhesive and bioadhesive properties, and their role as actuators.
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Affiliation(s)
- Mark Geoghegan
- School of Engineering, Newcastle University, Merz Court, Newcastle-upon-Tyne NE1 7RU, UK.
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18
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Schwarz UD. Visualized atom by atom. NATURE MATERIALS 2022; 21:140-142. [PMID: 34621060 DOI: 10.1038/s41563-021-01115-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Udo D Schwarz
- Departments of Mechanical Engineering & Materials Science and Chemical & Environmental Engineering, Yale University, New Haven, CT, USA.
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19
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Sulkanen AR, Wang M, Swartz LA, Sung J, Sun G, Moore JS, Sottos NR, Liu GY. Production of Organizational Chiral Structures by Design. J Am Chem Soc 2022; 144:824-831. [PMID: 35005904 DOI: 10.1021/jacs.1c10491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Organizational chirality on surfaces has been of interest in chemistry and materials science due to its scientific importance as well as its potential applications. Current methods for producing organizational chiral structures on surfaces are primarily based upon the self-assembly of molecules. While powerful, the chiral structures are restricted to those dictated by surface reaction thermodynamics. This work introduces a method to create organizational chirality by design with nanometer precision. Using atomic force microscopy-based nanolithography, in conjunction with chosen surface chemistry, various chiral structures are produced with nanometer precision, from simple spirals and arrays of nanofeatures to complex and hierarchical chiral structures. The size, geometry, and organizational chirality is achieved in deterministic fashion, with high fidelity to the designs. The concept and methodology reported here provide researchers a new and generic means to carry out organizational chiral chemistry, with the intrinsic advantages of chiral structures by design. The results open new and promising applications including enantioselective catalysis, separation, and crystallization, as well as optical devices requiring specific polarized radiation and fabrication and recognition of chiral nanomaterials.
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Affiliation(s)
- Audrey R Sulkanen
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Minyuan Wang
- Agricultural and Environmental Chemistry Graduate Group, University of California, Davis, California 95616, United States
| | - Logan A Swartz
- Biophysics Graduate Group, University of California, Davis, California 95616, United States
| | - Jaeuk Sung
- Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Gang Sun
- Agricultural and Environmental Chemistry Graduate Group, University of California, Davis, California 95616, United States.,Department of Biological and Agricultural Engineering, University of California, Davis, California 95616, United States
| | - Jeffrey S Moore
- Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Nancy R Sottos
- Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Gang-Yu Liu
- Department of Chemistry, University of California, Davis, California 95616, United States.,Agricultural and Environmental Chemistry Graduate Group, University of California, Davis, California 95616, United States.,Biophysics Graduate Group, University of California, Davis, California 95616, United States
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20
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Zhang LQ, Yang SG, Zhang JH, Zhong KP, Zhao ZG, Chen YH, Lei J, Zhang QY, Li ZM. Insight into the Excellent Tribological Performance of Highly Oriented Poly(phenylene sulfide). CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2672-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Moreira RA, Baker JL, Guzman HV, Poma AB. Assessing the Stability of Biological Fibrils by Molecular-Scale Simulations. Methods Mol Biol 2022; 2340:357-378. [PMID: 35167082 DOI: 10.1007/978-1-0716-1546-1_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The nanomechanical characterization of several biological fibrils that are the result of protein aggregation via molecular dynamics simulation is nowadays feasible, and together with atomic force microscopy experiments has widened our understanding of the forces in the regime of pN-nN and system sizes of about hundreds of nanometers. Several methodologies have been developed to achieve this target, and they range from the atomistic representation via molecular force fields to coarse-grained strategies that provide comparable results with experiments in a systematic way. In this chapter, we discuss several methodologies for the calculation of mechanical parameters, such as the elastic constants of relevant biological systems. They are presented together with details about parameterization and current limitations. Then, we discuss some of the applications of such methodologies for the description of bacterial filament and β-amyloid systems. Finally, the latest lines of development are discussed.
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Affiliation(s)
- Rodrigo A Moreira
- Soft Matter and Biosystems, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
| | - Joseph L Baker
- Department of Chemistry, The College of New Jersey, Ewing, NJ, USA
| | | | - Adolfo B Poma
- Soft Matter and Biosystems, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland.
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22
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Brazil O, Pethica JB, Pharr GM. The contribution of plastic sink-in to the static friction of single asperity microscopic contacts. Proc Math Phys Eng Sci 2021. [DOI: 10.1098/rspa.2021.0502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We report microscale friction experiments for diamond/metal and diamond/silica contacts under gigapascal contact pressures. Using a new nanoprobe technique that has a sufficient dynamic range of force and stiffness, we demonstrate the processes involved in the transition from purely interface sliding at the nanoscale to the situation where at least one of the sliding bodies undergoes some plastic deformation. For sliding of micrometre-sized tips on metallic substrates, additional local plastic yielding of the substrate resulting from tangential tractions causes the tip to sink into the surface, increasing the contact area in the direction of loading and resulting in a static friction coefficient higher than the kinetic during ploughing. This sink-in is largely absent in fused silica, and no friction drop is observed, along with lower friction in general. The transition from sink-in within the static friction regime to ploughing in the sliding friction regime is mediated by failure of the contact interface, indicated by a sharp increase in energy dissipation. At lower contact pressures, the elastic interfacial sliding behaviour characteristic of scanning probe or surface force apparatus experiments is recovered, bridging the gap between the exotic realm of nanotribology and plasticity-dominated macroscale friction.
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Affiliation(s)
- Owen Brazil
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77840, USA
| | - John B. Pethica
- School of Physics, CRANN and AMBER, Trinity College Dublin, Dublin, Ireland
| | - George M. Pharr
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77840, USA
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23
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Perotti BL, Cammarata A, Cemin F, Sales de Mello SR, Leidens LM, Echeverrigaray FG, Minea T, Alvarez F, Michels AF, Polcar T, Figueroa CA. Phototribology: Control of Friction by Light. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43746-43754. [PMID: 34491711 DOI: 10.1021/acsami.1c13054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In dry sliding, the coefficient of friction depends on the material pair and contact conditions. If the material and operating conditions remain unchanged, the coefficient of friction is constant. Obviously, we can tune friction by surface treatments, but it is a nonreversible process. Here, we report active control of friction forces on TiO2 thin films under UV light. It is reversible and stable and can be tuned/controlled with the light wavelength. The analysis of atomic force microscopy signals by wavelet spectrograms reveals different mechanisms acting in the darkness and under UV. Ab initio simulations on UV light-exposed TiO2 show a lower atomic orbital overlapping on the surface, which leads to a friction reduction of up to 60%. We suggest that photocontrol of friction is due to the modification of atomic orbital interactions from both surfaces at the sliding interface.
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Affiliation(s)
- Bruna L Perotti
- Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil
| | - Antonio Cammarata
- Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technicka 2, Prague 6 16627, Czech Republic
| | - Felipe Cemin
- Laboratoire de Physique des Gaz et des Plasmas (LPGP), Université Paris-Saclay, CNRS, Orsay Cedex F-91405, France
| | - Saron R Sales de Mello
- Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil
| | - Leonardo M Leidens
- Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil
| | - Fernando G Echeverrigaray
- Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil
| | - Tiberiu Minea
- Laboratoire de Physique des Gaz et des Plasmas (LPGP), Université Paris-Saclay, CNRS, Orsay Cedex F-91405, France
| | - Fernando Alvarez
- Instituto de Física "Gleb Wataghin" (IFGW), Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
| | - Alexandre F Michels
- Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil
| | - Tomas Polcar
- Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technicka 2, Prague 6 16627, Czech Republic
- Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, U.K
| | - Carlos A Figueroa
- Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil
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24
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Wang W, Dietzel D, Schirmeisen A. Thermal Activation of Nanoscale Wear. PHYSICAL REVIEW LETTERS 2021; 126:196101. [PMID: 34047617 DOI: 10.1103/physrevlett.126.196101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/20/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Nanoscale wear tracks on ionic crystals are created by reciprocating single asperity scratch tests using atomic force microscopy. The wear characteristics are analyzed by the scratch depth as a function of surface temperature from 25 to 300 K. The average wear depth shows a nonmonotonic behavior as a function of temperature, with a transition between two different regimes characterized by the occurrence of quasiperiodic ripple formation. A thermally activated bond breaking model quantitatively explains the wear data in the low temperature, nonripple regime, but fails above the temperature threshold. This discrepancy is resolved with a geometric separation of the ripple mounds from the troughs, leading to full agreement with Arrhenius kinetics over the full temperature range.
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Affiliation(s)
- Wen Wang
- School of Mechanical Engineering, Southwest Jiaotong University, 610031 Chengdu, China
- Institute of Applied Physics, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
| | - Dirk Dietzel
- Institute of Applied Physics, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
- Center for Materials Research, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
| | - André Schirmeisen
- Institute of Applied Physics, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
- Center for Materials Research, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
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25
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Mears M, Zhang ZJ, Jackson RCD, Si Y, Bradford TJB, Torkelson JM, Geoghegan M. Lateral diffusion of single poly(ethylene oxide) chains on the surfaces of glassy and molten polymer films. J Chem Phys 2021; 154:164902. [PMID: 33940801 DOI: 10.1063/5.0051351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Fluorescence correlation spectroscopy was used to show that the temperature-dependent diffusion coefficient of poly(ethylene oxide) (PEO) adsorbed on polystyrene and different poly(alkyl methacrylate) (PAMA) films in aqueous solution exhibited a maximum close to (but below) the surface glass transition temperature, Tgs, of the film. This elevated diffusion was observed over a small range of temperatures below Tgs for these surfaces, and at other temperatures, the diffusion was similar to that on silicon, although the diffusion coefficient for PEO on polystyrene at temperatures above Tgs did not completely decrease to that on silicon, in contrast to the PAMA surfaces. It is concluded that the enhanced surface mobility of the films near the surface glass transition temperature induces conformational changes in the adsorbed PEO. The origin of this narrow and dramatic increase in diffusion coefficient is not clear, but it is proposed that it is caused by a coupling of a dominant capillary mode in the liquid surface layer with the polymer. Friction force microscopy experiments also demonstrate an unexpected increase in friction at the same temperature as the increase in diffusion coefficient.
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Affiliation(s)
- Matthew Mears
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Zhenyu J Zhang
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Ryan C D Jackson
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Yuchen Si
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Tigerlily J B Bradford
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - John M Torkelson
- Department of Chemical and Biological Engineering and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Mark Geoghegan
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
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26
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Weber NA, Schmidt H, Sievert T, Jooss C, Güthoff F, Moshneaga V, Samwer K, Krüger M, Volkert CA. Polaronic Contributions to Friction in a Manganite Thin Film. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2003524. [PMID: 33898176 PMCID: PMC8061368 DOI: 10.1002/advs.202003524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/16/2020] [Indexed: 05/08/2023]
Abstract
Despite the huge importance of friction in regulating movement in all natural and technological processes, the mechanisms underlying dissipation at a sliding contact are still a matter of debate. Attempts to explain the dependence of measured frictional losses at nanoscale contacts on the electronic degrees of freedom of the surrounding materials have so far been controversial. Here, it is proposed that friction can be explained by considering the damping of stick-slip pulses in a sliding contact. Based on friction force microscopy studies of La(1- x )Sr x MnO3 films at the ferromagnetic-metallic to a paramagnetic-polaronic conductor phase transition, it is confirmed that the sliding contact generates thermally-activated slip pulses in the nanoscale contact, and argued that these are damped by direct coupling into the phonon bath. Electron-phonon coupling leads to the formation of Jahn-Teller polarons and to a clear increase in friction in the high-temperature phase. There is neither evidence for direct electronic drag on the atomic force microscope tip nor any indication of contributions from electrostatic forces. This intuitive scenario, that friction is governed by the damping of surface vibrational excitations, provides a basis for reconciling controversies in literature studies as well as suggesting possible tactics for controlling friction.
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Affiliation(s)
- Niklas A. Weber
- Institute of Materials PhysicsUniversity of GöttingenGöttingen37077Germany
| | - Hendrik Schmidt
- Institute of Materials PhysicsUniversity of GöttingenGöttingen37077Germany
| | - Tim Sievert
- Institute of Materials PhysicsUniversity of GöttingenGöttingen37077Germany
| | - Christian Jooss
- Institute of Materials PhysicsUniversity of GöttingenGöttingen37077Germany
- The International Center for Advanced Studies of Energy Conversion (ICASEC)University of GöttingenGöttingen37077Germany
| | - Friedrich Güthoff
- Institute of Physical ChemistryUniversity of GöttingenGöttingen37077Germany
| | - Vasily Moshneaga
- 1st Physics InstituteUniversity of GöttingenGöttingen37077Germany
| | - Konrad Samwer
- The International Center for Advanced Studies of Energy Conversion (ICASEC)University of GöttingenGöttingen37077Germany
- 1st Physics InstituteUniversity of GöttingenGöttingen37077Germany
| | - Matthias Krüger
- Institute for Theoretical PhysicsUniversity of GöttingenGöttingen37077Germany
| | - Cynthia A. Volkert
- Institute of Materials PhysicsUniversity of GöttingenGöttingen37077Germany
- The International Center for Advanced Studies of Energy Conversion (ICASEC)University of GöttingenGöttingen37077Germany
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27
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Liamas E, Connell SD, Zembyla M, Ettelaie R, Sarkar A. Friction between soft contacts at nanoscale on uncoated and protein-coated surfaces. NANOSCALE 2021; 13:2350-2367. [PMID: 33367416 DOI: 10.1039/d0nr06527g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The understanding of friction on soft sliding biological surfaces at the nanoscale is poorly understood as hard interfaces are frequently used as model systems. Herein, we studied the influence of elastic modulus on the frictional properties of model surfaces at the nanoscale for the first time. We prepared model silicone-based elastomer surfaces with tuneable modulus ranging from hundreds of kPa to a few MPa, similar to those found in real biological surfaces, and employed atomic force microscopy to characterize their modulus, adhesion, and surface morphology. Consequently, we used friction force microscopy to investigate nanoscale friction in hard-soft and soft-soft contacts using spherical colloidal probes covered by adsorbed protein films. Unprecedented results from this study reveal that modulus of a surface can have a significant impact on the frictional properties of protein-coated surfaces with higher deformability leading to lower contact pressure and, consequently, decreased friction. These important results pave the way forward for designing new functional surfaces for serving as models of appropriate deformability to replicate the mechanical properties of the biological structures and processes for accurate friction measurements at nanoscale.
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Affiliation(s)
- Evangelos Liamas
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, UK.
| | - Morfo Zembyla
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Rammile Ettelaie
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
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Liu Y, Wang K, Xu Q, Zhang J, Hu Y, Ma T, Zheng Q, Luo J. Superlubricity between Graphite Layers in Ultrahigh Vacuum. ACS APPLIED MATERIALS & INTERFACES 2020; 12:43167-43172. [PMID: 32840104 DOI: 10.1021/acsami.0c05422] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Graphite has been conventionally believed to exhibit an inferior lubricating performance with significantly larger friction coefficient and wear rate in a vacuum environment than in ambient air. Dangling bonds at the edge planes of graphite, accounting for the high friction in inert atmosphere are saturated by chemisorbed vapor molecules in air, which contributes to low surface adhesion and low friction. However, there is still a lack of direct experimental evidence whether basal planes of graphite excluding the negative effects of edges or dangling bonds shows intrinsic lubricity when sliding under ultrahigh vacuum (UHV) conditions. By the interlayer friction measurement enabled by graphite flake-wrapped atomic force microscope tips in UHV, we show a record-low friction coefficient of 4 × 10-5 (slope of friction vs normal force curve) when sliding between graphite layers, which is much lower than that in ambient air. This discrepancy manifests the intrinsic sliding frictional behavior between the graphite basal planes when the tribo-materials and experimental conditions are well-designed and strictly controlled. In addition, the temperature dependence of the kinetic friction between the graphite layers has been investigated under UHV conditions over the temperature range of 125-448 K, which is consistent with the thermally activated process.
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Affiliation(s)
- Yanmin Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Beijing Institute of Control Engineering, Beijing 100094, China
| | - Kang Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Qiang Xu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jie Zhang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Yuanzhong Hu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Tianbao Ma
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Quanshui Zheng
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Jianbin Luo
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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Vanossi A, Bechinger C, Urbakh M. Structural lubricity in soft and hard matter systems. Nat Commun 2020; 11:4657. [PMID: 32938930 PMCID: PMC7495432 DOI: 10.1038/s41467-020-18429-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/17/2020] [Indexed: 11/09/2022] Open
Abstract
Over the recent decades there has been tremendous progress in understanding and controlling friction between surfaces in relative motion. However the complex nature of the involved processes has forced most of this work to be of rather empirical nature. Two very distinctive physical systems, hard two-dimensional layered materials and soft microscopic systems, such as optically or topographically trapped colloids, have recently opened novel rationally designed lines of research in the field of tribology, leading to a number of new discoveries. Here, we provide an overview of these emerging directions of research, and discuss how the interplay between hard and soft matter promotes our understanding of frictional phenomena. Structural lubricity is one of the most interesting concepts in modern tribology, which promises to achieve ultra-low friction over a wide range of length-scales. Here the authors highlight novel research lines in this area achievable by combining theoretical and experimental efforts on hard two-dimensional materials and soft colloidal and cold ion systems.
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Affiliation(s)
- Andrea Vanossi
- CNR-IOM Democritos National Simulation Center, Trieste, Italy. .,International School for Advanced Studies (SISSA), Trieste, Italy.
| | | | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, 6997801, Israel.
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31
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Dong Y, Tao Y, Feng R, Zhang Y, Duan Z, Cao H. Phonon dissipation in friction with commensurate-incommensurate transition between graphene membranes. NANOTECHNOLOGY 2020; 31:285711. [PMID: 32252042 DOI: 10.1088/1361-6528/ab86ec] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To examine phonon transport during the friction process of commensurate-incommensurate transition, the vibrational density of states of contact surfaces is calculated based on molecular dynamics simulations. The results indicate that, compared with the static state, the relative sliding of the contact surfaces causes a blue shift in the interfacial phonon spectrum in or close to commensurate contact, whereas the contrast of the phonon spectrum in incommensurate contact is almost indiscernible. Further findings suggest that the cause of friction can be attributed to the excitation of new in-plane acoustic modes, which provide the most efficient energy dissipation channels in the friction process. In addition, when the tip and the substrate are subjected to a same biaxial compressive/tensile strain, fewer new acoustic modes are excited than in the no strain case. Thus, the friction can be controlled by applying in-plane strain even in commensurate contact. The contribution of the excited acoustic modes to friction at various frequency bands is also calculated, which provides theoretical guidance for controlling friction by adjusting excitation phonon modes.
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Affiliation(s)
- Yun Dong
- School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, People's Republic of China. School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
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Liamas E, Connell SD, Ramakrishna SN, Sarkar A. Probing the frictional properties of soft materials at the nanoscale. NANOSCALE 2020; 12:2292-2308. [PMID: 31951242 DOI: 10.1039/c9nr07084b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The understanding of friction in soft materials is of increasing importance due to the demands of industries such as healthcare, biomedical, food and personal care, the incorporation of soft materials into technology, and in the study of interacting biological interfaces. Many of these processes occur at the nanoscale, but even at micrometer length scales there are fundamental aspects of tribology that remain poorly understood. With the advent of Friction Force Microscopy (FFM), there have been many fundamental insights into tribological phenomena at the atomic scale, such as 'stick-slip' and 'super-lubricity'. This review examines the growing field of soft tribology, the experimental aspects of FFM and its underlying theory. Moving to the nanoscale changes the contact mechanics which govern adhesive forces, which in turn play a pivotal role in friction, along with the deformation of the soft interface and dissipative phenomena. We examine recent progress and future prospects in soft nanotribology.
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Affiliation(s)
- Evangelos Liamas
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, UK
| | | | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
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Abstract
Controlling, and in many cases minimizing, friction is a goal that has long been pursued in history. From the classic Amontons-Coulomb law to the recent nanoscale experiments, the steady-state friction is found to be an inherent property of a sliding interface, which typically cannot be altered on demand. In this work, we show that the friction on a graphene sheet can be tuned reversibly by simple mechanical straining. In particular, by applying a tensile strain (up to 0.60%), we are able to achieve a superlubric state (coefficient of friction nearly 0.001) on a suspended graphene. Our atomistic simulations together with atomically resolved friction images reveal that the in-plane strain effectively modulates the flexibility of graphene. Consequently, the local pinning capability of the contact interface is changed, resulting in the unusual strain-dependent frictional behavior. This work demonstrates that the deformability of atomic-scale structures can provide an additional channel of regulating the friction of contact interfaces involving configurationally flexible materials.
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Vialar P, Merzeau P, Barthel E, Giasson S, Drummond C. Interaction between Compliant Surfaces: How Soft Surfaces Can Reduce Friction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15723-15728. [PMID: 31566381 DOI: 10.1021/acs.langmuir.9b02384] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We describe how a long-range repulsive interaction can surreptitiously modify the effective geometry of approaching compliant surfaces, with significant consequences on friction. We investigated the behavior under shear and compression of mica surfaces coated with poly(N-isopropylacrylamide) pNIPAM-based cationic microgels. We show that local surface deformations as small as a few nanometers must be considered to understand the response of such surfaces under compression and shear, in particular when the range of action of normal and friction forces are significantly different, as is often the case for macromolecular lubrication. Under these conditions, a subtle interplay between normal forces and surface compliance may significantly reduce friction increment by limiting the minimum approach of the surfaces under pressure. We found that stiffening of compressed microgels confined in the region of closest approach make it increasingly difficult to reduce the gap between the mica surfaces, limiting the deformation of microgels distant from the contact apex and their contribution to global friction while increasing the effective contact radius. These findings reveal a simple mechanism for a robust control of lubrication: by properly tuning the stiffness and geometry of the interacting bodies, for an ad hoc long-range interaction, the growth of friction with applied normal load can be significantly hindered. Thus, substrate compliance is as significant as surface interaction in the design of low friction, long life tribological systems.
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Affiliation(s)
- Pierre Vialar
- CNRS, Centre de Recherche Paul Pascal (CRPP), UMR 5031 , F-33600 Pessac , France
- Université Bordeaux 1, CRPP , F-33600 Pessac , France
| | - Pascal Merzeau
- CNRS, Centre de Recherche Paul Pascal (CRPP), UMR 5031 , F-33600 Pessac , France
- Université Bordeaux 1, CRPP , F-33600 Pessac , France
| | - Etienne Barthel
- Laboratoire Sciences et Ingénierie de la Matière Molle, ESPCI Paris, CNRS, PSL University , 75005 Paris , France
- Sorbonne Université, ESPCI Paris, Sciences et Ingénierie de la Matière Molle , 75005 Paris , France
| | - Suzanne Giasson
- Department of Chemistry and Faculty of Pharmacy , Université de Montréal , C.P. 6128, succursale Centre-Ville, Montréal , QC H3C 3J7 , Canada
| | - Carlos Drummond
- CNRS, Centre de Recherche Paul Pascal (CRPP), UMR 5031 , F-33600 Pessac , France
- Université Bordeaux 1, CRPP , F-33600 Pessac , France
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35
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Milne ZB, Bernal RA, Carpick RW. Sliding History-Dependent Adhesion of Nanoscale Silicon Contacts Revealed by in Situ Transmission Electron Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15628-15638. [PMID: 31397572 DOI: 10.1021/acs.langmuir.9b02029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nanoscale asperity-on-asperity sliding experiments were conducted using a nanoindentation apparatus inside a transmission electron microscope, allowing for atomic-scale resolution of contact formation, sliding, and adhesive separation of two silicon nanoasperities in real time. The formation and separation of the contacts without sliding revealed adhesion forces often below detectable limits (ca. 5 nN) or at most equal to values expected from van der Waals forces. Lateral sliding during contact by distances ranging from 3.7 μm down to as little as 20 nm resulted in an average 19× increase in the adhesive pull-off force, with increases as large as 32× seen. Adhesion after sliding increased with both the sliding speed and the applied normal contact stress. Unlike cold welding, where irreversible material changes like flow occur, these effects were repeatable and reversible multiple times, for multiple pairs of asperities. We hypothesize that sliding removes passivating surface terminal species, most likely hydrogen or hydroxyl groups, making sites available to form strong covalent bonds across the interface that increase adhesion. Upon separation, repassivation occurs within the experimentally limited lower bound time frame of 5 s, with full recovery of low adhesion. The results demonstrate the strong sliding history-dependence of adhesion, which hinges on the interplay between tribologically induced removal of adsorbed species and repassivation of unsaturated bonds on freshly separated surfaces by dissociative chemisorption.
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Affiliation(s)
- Zachary B Milne
- University of Pennsylvania , Department of Mechanical Engineering and Applied Mechanics , Philadelphia , Pennsylvania 19104 United States
| | - Rodrigo A Bernal
- University of Texas , Dallas, Department of Mechanical Engineering , Dallas , Texas 75080 United States
| | - Robert W Carpick
- University of Pennsylvania , Department of Mechanical Engineering and Applied Mechanics , Philadelphia , Pennsylvania 19104 United States
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36
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Borovsky BP, Garabedian NT, McAndrews GR, Wieser RJ, Burris DL. Integrated QCM-Microtribometry: Friction of Single-Crystal MoS 2 and Gold from μm/s to m/s. ACS APPLIED MATERIALS & INTERFACES 2019; 11:40961-40969. [PMID: 31604008 DOI: 10.1021/acsami.9b15764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two opposing microtribometry approaches have been developed over the past decade to help connect the dots between fundamental and practical tribology measurements: spring-based (e.g., AFM) approaches use low speed, low stiffness, and long relative slip length to quantify friction, while quartz crystal microbalance (QCM)-based approaches use high speed, high stiffness, and short relative slip length. Because the friction forces generated in these experiments are attributed to entirely different phenomena, it is unclear if or how the resulting friction forces are related. This study aims to resolve this uncertainty by integrating these distinct techniques into a single apparatus that allows two independent measurements of friction at a single interface. Alumina microspheres were tested against single-crystal MoS2, a model nominally wear-free solid lubricant, and gold, a model metal control, at loads between 0.01 and 1 mN. The combined results from both measurement approaches gave friction coefficients (mean ± standard error) of 0.087 ± 0.007 and 0.27 ± 0.02 for alumina-MoS2 and alumina-gold, respectively. The observed agreement between these methods for two different material systems suggests that friction in microscale contacts can be far less sensitive to external effects from compliance and slip speed than currently thought. Perhaps more importantly, this Article describes and validates a novel approach to closing the "tribology gap" while demonstrating how integration creates new opportunities for fundamental studies of practical friction.
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Affiliation(s)
- B P Borovsky
- Department of Physics , St. Olaf College , Northfield , Minnesota 55057 , United States
| | - N T Garabedian
- Department of Mechanical Engineering , University of Delaware , Newark , Delaware 19716 , United States
| | - G R McAndrews
- Department of Physics , St. Olaf College , Northfield , Minnesota 55057 , United States
| | - R J Wieser
- Department of Physics , St. Olaf College , Northfield , Minnesota 55057 , United States
| | - D L Burris
- Department of Mechanical Engineering , University of Delaware , Newark , Delaware 19716 , United States
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37
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In-Liquid Lateral Force Microscopy of Micropatterned Surfaces in a Fatty Acid Solution under Boundary Lubrication. Sci Rep 2019; 9:15236. [PMID: 31645627 PMCID: PMC6811562 DOI: 10.1038/s41598-019-51687-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/07/2019] [Indexed: 11/11/2022] Open
Abstract
This study aims to investigate the influence of surface morphology on boundary-lubricated friction in a stearic acid solution. The surface morphology was controlled by fabricating submicrometer line-and-space patterns on Si(100) surface via photolithography. The boundary-lubricated friction on the patterns was measured by in-liquid lateral force microscopy for both transverse and longitudinal ridges, with respect to the sliding direction; the highest friction was observed on longitudinal ridges and grooves, which is in agreement with the tendency observed in our previous friction studies on steel surfaces. To further investigate this phenomenon, some additional patterns having different submicrometer morphologies were prepared and their friction characteristics were investigated. On the patterns not allowing the fluid to flow along the grooves, the frictional forces were equivalent for transverse and longitudinal grooves and ridges. Therefore, the high friction observed on the longitudinal ridges was caused by flowing out of fluid along the grooves, and it was possible to conclude that the fluidity around the submicrometer ridges and grooves influences the friction-reducing effect of stearic acid in boundary lubrication regime.
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38
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Yang F, Yang J, Qi Y, de Boer MP, Carpick RW, Rappe AM, Srolovitz DJ. Mechanochemical Effects of Adsorbates at Nanoelectromechanical Switch Contacts. ACS APPLIED MATERIALS & INTERFACES 2019; 11:39238-39247. [PMID: 31547645 DOI: 10.1021/acsami.9b09707] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Herein, classical molecular dynamics simulations are used to examine nanoscale adsorbate reactions during the cyclic opening and closing of nanoelectromechanical system (NEMS) switches. We focus upon how reactions change metal/metal conductive contact area, asperity morphology, and plastic deformation. We specifically consider Pt, which is often used as an electrode material for NEMS switches. The structural evolution of asperity contacts in gaseous environments with molecules which can potentially form tribopolymers is determined by various factors, for example, contact forces, partial pressure and molecular weight of gas, and the fundamental reaction rates of surface adsorption and adsorbate linkages. The modeled systems exhibit significant changes during the first few cycles, but as the number of contact cycles increases, the system finds a steady-state where the morphologies, Pt/Pt contact area, oligomer chain lengths, amount of Pt transfer between opposing surfaces, and deformation rate stabilize. The stress generated during asperity contact increases the rate of reactions among the adsorbates in the contact region. This makes the size of the adsorbate molecules increase and thus more exposed metal, which implies higher electrical conductance in the closed contact, but more plastic deformation, metal-metal transfer, and mechanical work expended in each contact cycle.
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Affiliation(s)
| | | | | | - Maarten P de Boer
- Department of Mechanical Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | | | | | - David J Srolovitz
- Department of Materials Science and Engineering , City University of Hong Kong , Kowloon , Hong Kong SAR
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39
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Jao CY, Samaimongkol P, Robinson HD. Tunable gap plasmons in gold nanospheres adsorbed into a pH-responsive polymer film. J Colloid Interface Sci 2019; 553:197-209. [PMID: 31203004 DOI: 10.1016/j.jcis.2019.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/01/2019] [Accepted: 06/06/2019] [Indexed: 12/24/2022]
Abstract
HYPOTHESIS Plasmon nanorulers are exquisitely sensitive distance sensors that are based on the electromagnetic interaction between metal nanoparticles and surfaces. We hypothesize that nanorulers can act as quantitative probes of processes such as particle aggregation and adsorption, and deploy them to investigate particle adsorption onto stimulus-responsive polymer films. While such systems have previously been qualitatively investigated with plasmon nanorulers, our quantitative analysis should provide deeper insights. EXPERIMENT Gold nanospheres are adsorbed from solution onto pH-responsive, amine-rich polyelectrolyte multilayer (PEM) films that are either directly deposited on a gold substrate or onto an intermediate self-assembled monolayer (SAM) of charged thiols. Fitting the optical scattering spectrum to a full-wave calculation, we quantify the sphere-substrate gap distance with good accuracy. FINDINGS We find that the gold spheres partially embed into the PEMs rather than ride on top of them, and that although the amount of actuation of the spheres afforded by tuning the pH is well controlled, it is significantly smaller than the corresponding thickness changes in unstrained films. Further, the presence of a SAM below the PEM increases the amount of polymer in the PEM, except for the thickest and most highly charged films, where the SAM instead appears to displace from the area below the nanospheres.
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Affiliation(s)
- Chih-Yu Jao
- Department of Physics, Virginia Tech, United States
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40
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Colazzo L, Mohammed MSG, Gallardo A, Abd El-Fattah ZM, Pomposo JA, Jelínek P, de Oteyza DG. Controlling the stereospecific bonding motif of Au-thiolate links. NANOSCALE 2019; 11:15567-15575. [PMID: 31402370 DOI: 10.1039/c9nr04383g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Over the last decades, organosulfur compounds at the interface of noble metals have proved to be extremely versatile systems for both fundamental and applied research. However, the anchoring of thiols to gold remained an object of controversy for a long time. The RS-Au-SR linkage, in particular, is a robust bonding configuration that displays interesting properties. It is generated spontaneously at room temperature and can be used for the production of extended molecular nanostructures. In this work we explore the behavior of 1,4-bis(4-mercaptophenyl)benzene (BMB) on the Au(111) surface, which results in the formation of 2D crystalline metal-organic assemblies stabilized by this type of Au-thiolate bonds. We show how to control the thiolate's stereospecific bonding motif and thereby choose whether to form ordered arrays of Au3BMB3 units with embedded triangular nanopores or linearly stacked metal-organic chains. The former turn out to be thermodynamically favored structures and display confinement of the underneath Au(111) surface state. The electronic properties of single molecules as well as of the 2D crystalline self-assemblies have been characterized both on the metal-organic backbone and inside the associated pores.
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Affiliation(s)
- Luciano Colazzo
- Donostia International Physics Center, 20018 San Sebastián, Spain. and Centro de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
| | - Mohammed S G Mohammed
- Donostia International Physics Center, 20018 San Sebastián, Spain. and Centro de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
| | - Aurelio Gallardo
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic and Faculty of Mathematics and Physics, Charles University, 180 00 Prague, Czech Republic
| | | | - José A Pomposo
- Centro de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain and Ikerbasque, Basque Foundation for Science, Bilbao, Spain and Departamento de Física de Materiales, Universidad del País Vasco (UPV/EHU), Apartado 1072, E-20800 San Sebastián, Spain
| | - Pavel Jelínek
- Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic
| | - Dimas G de Oteyza
- Donostia International Physics Center, 20018 San Sebastián, Spain. and Centro de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain and Ikerbasque, Basque Foundation for Science, Bilbao, Spain
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41
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Vazirisereshk MR, Ye H, Ye Z, Otero-de-la-Roza A, Zhao MQ, Gao Z, Johnson ATC, Johnson ER, Carpick RW, Martini A. Origin of Nanoscale Friction Contrast between Supported Graphene, MoS 2, and a Graphene/MoS 2 Heterostructure. NANO LETTERS 2019; 19:5496-5505. [PMID: 31267757 DOI: 10.1021/acs.nanolett.9b02035] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ultralow friction can be achieved with 2D materials, particularly graphene and MoS2. The nanotribological properties of these different 2D materials have been measured in previous atomic force microscope (AFM) experiments sequentially, precluding immediate and direct comparison of their frictional behavior. Here, friction is characterized at the nanoscale using AFM experiments with the same tip sliding over graphene, MoS2, and a graphene/MoS2 heterostructure in a single measurement, repeated hundreds of times, and also measured with a slowly varying normal force. The same material systems are simulated using molecular dynamics (MD) and analyzed using density functional theory (DFT) calculations. In both experiments and MD simulations, graphene consistently exhibits lower friction than the MoS2 monolayer and the heterostructure. In some cases, friction on the heterostructure is lower than that on the MoS2 monolayer. Quasi-static MD simulations and DFT calculations show that the origin of the friction contrast is the difference in energy barriers for a tip sliding across each of the three surfaces.
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Affiliation(s)
- Mohammad R Vazirisereshk
- Department of Mechanical Engineering , University of California , Merced , California 95343 , United States
| | - Han Ye
- Department of Mechanical Engineering and Applied Mechanics , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Zhijiang Ye
- Department of Mechanical and Manufacturing , Miami University , Oxford , Ohio 45056 , United States
| | - Alberto Otero-de-la-Roza
- Departamento de Quı́mica Fı́sica y Analı́tica, Facultad de Quı́mica , Universidad de Oviedo , 33006 Oviedo , Spain
| | - Meng-Qiang Zhao
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Zhaoli Gao
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - A T Charlie Johnson
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Erin R Johnson
- Department of Chemistry , Dalhousie University , Halifax , NS B3H 4R2 , Canada
| | - Robert W Carpick
- Department of Mechanical Engineering and Applied Mechanics , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Ashlie Martini
- Department of Mechanical Engineering , University of California , Merced , California 95343 , United States
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42
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Ranjan A, Pey KL, O'Shea SJ. The interplay between drift and electrical measurement in conduction atomic force microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:073701. [PMID: 31370442 DOI: 10.1063/1.5095647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/05/2019] [Indexed: 06/10/2023]
Abstract
In Conduction Atomic Force Microscopy (CAFM), it is sometimes required to monitor electrical data at a single location over an extended period of time. However, thermal drift of the microscope will cause the tip to move with respect to the sample and thus limit the collection of data. We investigate a method to prolong the time a tip dwells at a location by choosing the AFM cantilever to have small spring constants in the lateral directions. The basis of the approach is that the tip can only move (or slip) once the lateral forces caused by drift overcome the friction force pinning the tip to the surface. We demonstrate the effect experimentally using platinum wire tips and diamond coated tips on SiO2 and HfO2 dielectric films. Simultaneous measurement of the current flow and lateral force signals show that the onset of tip slipping correlates with the beginning of a decrease in the measured current flow, and the onset of slip is prolonged for blunt tips or cantilevers having soft lateral spring constants. The approach not only provides a way to improve the CAFM method for time dependent measurements but also assists in interpreting CAFM data in the presence of drift.
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Affiliation(s)
- A Ranjan
- Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372
| | - K L Pey
- Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372
| | - S J O'Shea
- Institute of Materials Research and Engineering, Agency for Science Technology and Research, 2 Fusionopolis Way, Singapore 138634
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Xiao C, Xin X, He X, Wang H, Chen L, Kim SH, Qian L. Surface Structure Dependence of Mechanochemical Etching: Scanning Probe-Based Nanolithography Study on Si(100), Si(110), and Si(111). ACS APPLIED MATERIALS & INTERFACES 2019; 11:20583-20588. [PMID: 31008584 DOI: 10.1021/acsami.9b00133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We employed a scanning probe-based lithography process on single-crystalline Si(100), Si(110), and Si(111) surfaces and studied the effects of crystallographic surface structures on mechanochemical etching of silicon in liquid water. The facet angle and etching rate of the mechanochemical process were different from those of the purely chemical etching process. In liquid water, the shape of the mechanochemically etched nanochannel appeared to be governed by thermodynamics of the etched surface, rather than stress distribution. Analyzing the etch rate with the mechanically assisted Arrhenius-type kinetics model showed that the shear-induced hydrolysis activity varies drastically with the crystallographic structure of silicon surface.
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Affiliation(s)
- Chen Xiao
- Tribology Research Institute, State Key Laboratory of Traction Power , Southwest Jiaotong University , Chengdu 610031 , China
- Department of Chemical Engineering and Materials Research Institute , Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Xiaojun Xin
- Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education), Superconductivity and New Energy R&D Center , Mail stop 165#, Southwest Jiaotong University , Chengdu 610031 , China
| | - Xin He
- Department of Chemical Engineering and Materials Research Institute , Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Hongbo Wang
- Tribology Research Institute, State Key Laboratory of Traction Power , Southwest Jiaotong University , Chengdu 610031 , China
| | - Lei Chen
- Tribology Research Institute, State Key Laboratory of Traction Power , Southwest Jiaotong University , Chengdu 610031 , China
| | - Seong H Kim
- Tribology Research Institute, State Key Laboratory of Traction Power , Southwest Jiaotong University , Chengdu 610031 , China
- Department of Chemical Engineering and Materials Research Institute , Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Linmao Qian
- Tribology Research Institute, State Key Laboratory of Traction Power , Southwest Jiaotong University , Chengdu 610031 , China
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Abstract
This paper describes a simple method to pattern nanoparticles on planar surfaces using the antifouling property of poly(ethylene glycol) monolayers deposited from a solution on the native oxide of titanium. Atomic force microcopy was used to pattern the poly(ethylene glycol) monolayers producing protein active sites on the protein-resistant surface. Patterns with different sizes have been generated by shaving the monolayers with different repetitions. Friction force microscopy was used to image the patterns. The smallest patterns are 50 nm and the largest patterns are 500 nm at full width half maximum. The smallest pattern was produced with one shave, whereas the largest pattern was produced by shaving the monolayers 112 times. Protein-coated nanoparticles were immobilised on the shaved (protein active) part of the monolayers by dipping the patterned samples into a solution that contains 2% by volume protein-functionalized nanoparticles with a nominal diameter of 40 nm. Atomic force microscopy was used to take a topographic image of the samples. The topographic image showed that the protein-functionalized nanoparticles were attached onto the shaved part of the substrate but not on the poly(ethylene glycol)-covered part of the substrate. The level of aggregation of the nanoparticles was also investigated from the topographic image. The section analysis of the topographic image of the nanoparticle patterns showed a height of 40 nm which proved that only a monolayer of particles were deposited on the shaved part of the monolayer.
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Dollekamp E, Bampoulis P, Siekman MH, Kooij ES, Zandvliet HJW. Tuning the Friction of Graphene on Mica by Alcohol Intercalation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4886-4892. [PMID: 30883130 PMCID: PMC6459005 DOI: 10.1021/acs.langmuir.9b00471] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Indexed: 06/09/2023]
Abstract
The friction of graphene on mica was studied using lateral force microscopy. We observed that intercalation of alcohol molecules significantly increases the friction of graphene, as compared to water. An increase of 1.8, 2.4, and 5.9 times in friction between the atomic force microscopy tip and single-layer graphene was observed for methanol, ethanol, and 2-propanol, respectively. Moreover, the friction of graphene is found to be higher for single-layer graphene than for multilayer graphene. We attribute the increase in friction to the additional vibrational modes of alcohol molecules. The significant variation of the frictional characteristics of graphene at the nanoscale by altering the intercalant could open up applications for the next-generation nanolubricants and nanodevices.
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Nowakowski K, Zandvliet HJW, Bampoulis P. Barrier Inhomogeneities in Atomic Contacts on WS 2. NANO LETTERS 2019; 19:1190-1196. [PMID: 30582818 DOI: 10.1021/acs.nanolett.8b04636] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The down-scaling of electrical components requires a proper understanding of the physical mechanisms governing charge transport. Here, we have investigated atomic-scale contacts and their transport characteristics on WS2 using conductive atomic force microscopy (c-AFM). We demonstrate that c-AFM can provide true atomic resolution, revealing atom vacancies, adatoms, and periodic modulations arising from electronic effects. Moreover, we find a lateral variation of the surface conductivity that arises from the lattice periodicity of WS2. Three distinct sites are identified, i.e., atop, bridge, and hollow. The current transport across these atomic metal-semiconductor interfaces is understood by considering thermionic emission and Fowler-Nordheim tunnelling. Current modulations arising from point defects and the contact geometry promise a novel route for the direct control of atomic point contacts in diodes and devices.
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Affiliation(s)
- Krystian Nowakowski
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology , University of Twente , P.O. Box 217, 7500AE Enschede , The Netherlands
| | - Harold J W Zandvliet
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology , University of Twente , P.O. Box 217, 7500AE Enschede , The Netherlands
| | - Pantelis Bampoulis
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology , University of Twente , P.O. Box 217, 7500AE Enschede , The Netherlands
- Physikalisches Institut , Universität zu Köln , Zülpicher Straße 77 , 50937 Köln , Germany
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Sulkanen AR, Sung J, Robb MJ, Moore JS, Sottos NR, Liu GY. Spatially Selective and Density-Controlled Activation of Interfacial Mechanophores. J Am Chem Soc 2019; 141:4080-4085. [DOI: 10.1021/jacs.8b10257] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Audrey R. Sulkanen
- Department of Chemistry, University of California, Davis, California 95616, United States
| | | | - Maxwell J. Robb
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | | | | | - Gang-yu Liu
- Department of Chemistry, University of California, Davis, California 95616, United States
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Krylov SY. Nontrivial Consequences of Thermal Delocalization of Mechanical Nanocontact upon Friction in the Atomic Scale. COLLOID JOURNAL 2019. [DOI: 10.1134/s1061933x18060054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Tran-Khac BC, Kim HJ, DelRio FW, Chung KH. Operational and environmental conditions regulate the frictional behavior of two-dimensional materials. APPLIED SURFACE SCIENCE 2019; 483:10.1016/j.apsusc.2019.03.249. [PMID: 31555019 PMCID: PMC6759862 DOI: 10.1016/j.apsusc.2019.03.249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The friction characteristics of single-layer h-BN, MoS2, and graphene were systematically investigated via friction force microscopy measurements at various operational (e.g., normal force and sliding speed) and environmental (e.g., relative humidity and thermal annealing) conditions. The low friction characteristics of these single-layer materials were clearly observed from the normal force-dependent friction results, and their interfacial shear strengths were further estimated using a Hertz-plus-offset model. In addition, speed-dependent friction characteristics clearly demonstrated two regimes of friction as a function of sliding speed - the first is the logarithmic increase in friction with sliding speed regime at sliding speeds smaller than the critical speed and the second is the friction plateau regime at sliding speeds greater than the critical speed. Fundamental parameters such as effective shape of the interaction potential and its corrugation amplitude for these single-layer materials were characterized using the thermally-activated Prandtl-Tomlinson model. Moreover, friction of single-layer h-BN, MoS2, and graphene was found to increase with relative humidity and decrease with thermal annealing; these trends were attributed to the diffusion of water molecules to the interface between the single-layer materials and their substrates, which leads to an increase in the puckering effect at the tip-material interface and interaction potential corrugation. The enhanced puckering effect was verified via molecular dynamics simulations. Overall, the findings enable a comprehensive understanding of friction characteristics for several classes of two-dimensional materials, which is important to elucidate the feasibility of using these materials as protective and solid-lubricant coating layers for nanoscale devices.
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Affiliation(s)
- Bien-Cuong Tran-Khac
- School of Mechanical Engineering, University of Ulsan, Ulsan 44610, Republic of Korea
| | - Hyun-Joon Kim
- Department of Precision Mechanical Engineering, Kyungpook National University, Sangju 37224, Republic of Korea
| | - Frank W. DelRio
- Applied Chemicals and Materials Division, Material Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - Koo-Hyun Chung
- School of Mechanical Engineering, University of Ulsan, Ulsan 44610, Republic of Korea
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50
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Tripathi M, Awaja F, Bizao RA, Signetti S, Iacob E, Paolicelli G, Valeri S, Dalton A, Pugno NM. Friction and Adhesion of Different Structural Defects of Graphene. ACS APPLIED MATERIALS & INTERFACES 2018; 10:44614-44623. [PMID: 30439287 DOI: 10.1021/acsami.8b10294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Graphene structural defects, namely edges, step-edges, and wrinkles, are susceptible to severe mechanical deformation and stresses under tribo-mechanical operations. Applied forces may cause deformation by folding, buckling, bending, and tearing of these defective sites of graphene, which lead to a remarkable decline in normal and friction load bearing capacity. In this work, we experimentally quantified the maximum sustainable normal and friction forces, corresponding to the damage thresholds of the different investigated defects as well as their pull-out (adhesion) forces. Horizontal wrinkles (with respect to the basal plane, i.e., folded) sustained the highest normal load, up to 317 nN, during sliding, whereas for vertical (i.e., standing) wrinkles, step-edges, and edges, the load bearing capacities are up to 113, 74, and 63 nN, respectively. The related deformation mechanisms were also experimentally investigated by varying the normal load up to the initiation of the damage from the defects and extended with the numerical results from molecular dynamics and finite element method simulations.
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Affiliation(s)
- Manoj Tripathi
- Department of Mathematics and Physical Sciences , University of Sussex , Brighton BN1 9RH , United Kingdom
| | - Firas Awaja
- Department of Orthopaedic Surgery , Medical University Innsbruck , Innrain 36, Innsbruck , Austria
| | - Rafael A Bizao
- Laboratory of Bio-Inspired & Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering , University of Trento , via Mesiano 77 I-38123 Trento , Italy
| | - Stefano Signetti
- Department of Mechanical Engineering , Korea Advanced institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu , Daejeon 34141 , Republic of Korea
| | - Erica Iacob
- Centre for Materials and Microsystems , Fondazione Bruno Kessler , via Sommarive 18 , I-38123 Trento , Italy
| | - Guido Paolicelli
- Istituto Nanoscienze , Consiglio Nazionale delle Ricerche , via G. Campi 213/a , 41125 - Modena , Italy
| | - Sergio Valeri
- Istituto Nanoscienze , Consiglio Nazionale delle Ricerche , via G. Campi 213/a , 41125 - Modena , Italy
- Dipartimento di Scienze Fisiche Informatiche e Matematiche (FIM) , Università di Modena e Reggio Emilia , via Campi 213/a , I-41125 Modena , Italy
| | - Alan Dalton
- Department of Mathematics and Physical Sciences , University of Sussex , Brighton BN1 9RH , United Kingdom
| | - Nicola Maria Pugno
- Laboratory of Bio-Inspired & Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering , University of Trento , via Mesiano 77 I-38123 Trento , Italy
- School of Engineering and Materials Science , Queen Mary University of London , Mile End Road , E1 4NS London United Kingdom
- Ket Lab , Edoardo Amaldi Foundation , via del Politecnico snc , I-00133 Roma , Italy
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