Superlubricity (original) (raw)
Supersmering (Engels: superlubricity) is een verschijnsel waarbij op atomaire schaal de wrijving tussen twee objecten (bijna) volledig verdwijnt. Het verschijnsel is al in 1990 voorspeld, maar pas in 2003 experimenteel waargenomen bij grafiet.
| Property | Value |
|---|---|
| dbo:abstract | Supraschmierfähigkeit (englisch: superlubricity) ist ein Phänomen, bei dem die Reibung fast vollständig verschwinden kann. Supraschmierfähigkeit tritt auf, wenn zwei kristalline Oberflächen zwar trocken, aber zueinander unpassend übereinander gleiten (siehe Inkommensurabilität aus dem Fachbereich der Kristallographie). Der Effekt wurde bereits 1991 postuliert, konnte aber erst 2004 mit großer Genauigkeit zwischen zwei Graphen-Oberflächen gemessen werden. Die Ähnlichkeit des Begriffs Supraschmierfähigkeit mit Begriffen wie Supraleitung und Suprafluidität ist irreführend, da diverse Verlustmechanismen zu endlichen (in der Regel kleinen) Reibungskräften führen können. Die Atome in Graphit orientieren sich in sechseckiger Art und Weise und formen eine atomare Berg- und Tal-Landschaft, die aussieht wie ein Ei-Karton. Wenn sich die zwei Graphen-Oberflächen in (alle 60 Grad) zueinander befinden, ist die Reibungskraft hoch. Wenn die beiden Oberflächen aus der Registry gedreht sind, ist die Reibung weitgehend reduziert. Das ist wie bei zwei Ei-Kartons die leichter übereinander gleiten können wenn sie gegeneinander verdreht sind. Im makroskopischen Maßstab konnte dieses Prinzip unter Verwendung von Graphen und Diamant-ähnlichen Kohlenstoffschichten demonstriert werden. Ein Zustand ultrakleiner Reibung kann auch erreicht werden, wenn eine scharfe Spitze über eine ebene Oberfläche gleitet und der Druck unterhalb eines bestimmten Schwellwertes gehalten wird, in Abhängigkeit vom von der Spitze gespürten Oberflächenpotenzial von der Steifigkeit des anliegenden Materials. Der Schwellenwert kann erheblich durch die Anregung des Gleiter-Systems auf seiner Resonanzfrequenz verbessert werden. Dies lässt darauf schließen, dass eine praktische Möglichkeit zur Begrenzung von Verschleiß bei NEMS (Nanoelectromechanical systems) besteht. (de) In physics (specifically tribology), superlubricity is a regime of motion in which friction vanishes or very nearly vanishes. What is a "vanishing" friction level is not clear, which makes the term quite vague. As an ad hoc definition, a kinetic coefficient of friction less than 0.01 can be adopted. This definition also requires further discussion and clarification. Superlubricity may occur when two crystalline surfaces slide over each other in dry incommensurate contact. This effect, also called , was suggested in 1991 and verified with great accuracy between two graphite surfaces in 2004.The atoms in graphite are oriented in a hexagonal manner and form an atomic hill-and-valley landscape, which looks like an egg-crate. When the two graphite surfaces are in registry (every 60 degrees), the friction force is high. When the two surfaces are rotated out of registry, the friction is greatly reduced. This is like two egg-crates which can slide over each other more easily when they are "twisted" with respect to each other. Observation of superlubricity in microscale graphite structures was reported in 2012, by shearing a square graphite mesa a few micrometers across, and observing the self-retraction of the sheared layer. Such effects were also theoretically described for a model of graphene and nickel layers. This observation, which is reproducible even under ambient conditions, shifts interest in superlubricity from a primarily academic topic, accessible only under highly idealized conditions, to one with practical implications for micro and nanomechanical devices. A state of ultralow friction can also be achieved when a sharp tip slides over a flat surface and the applied load is below a certain threshold. Such a "superlubric" threshold depends on the tip-surface interaction and the stiffness of the materials in contact, as described by the Tomlinson model.The threshold can be significantly increased by exciting the sliding system at its resonance frequency, which suggests a practical way to limit wear in nanoelectromechanical systems. Superlubricity was also observed between a gold AFM tip and Teflon substrate due to repulsive Van der Waals forces and hydrogen-bonded layer formed by glycerol on the steel surfaces. Formation of the hydrogen-bonded layer was also shown to lead to superlubricity between quartz glass surfaces lubricated by biological liquid obtained from mucilage of Brasenia schreberi. Other mechanisms of superlubricity may include: (a) Thermodynamic repulsion due to a layer of free or grafted macromolecules between the bodies so that the entropy of the intermediate layer decreases at small distances due to stronger confinement; (b) Electrical repulsion due to external electrical voltage; (c) Repulsion due to electrical double layer; (d) Repulsion due to thermal fluctuations. The similarity of the term superlubricity with terms such as superconductivity and superfluidity is misleading; other energy dissipation mechanisms can lead to a finite (normally small) friction force. Superlubricity is more analogous to phenomena such as superelasticity, in which substances such as Nitinol have very low, but nonzero, elastic moduli; supercooling, in which substances remain liquid until a lower-than-normal temperature; super black, which reflects very little light; giant magnetoresistance, in which very large but finite magnetoresistance effects are observed in alternating nonmagnetic and ferromagnetic layers; superhard materials, which are diamond or nearly as hard as diamond; and superlensing, which have a resolution which, while finer than the diffraction limit, is still finite. (en) Nel fenomeno della superlubrificazione l'attrito tra due superfici cristalline è pressoché nullo. La superlubrificazione ha luogo quando le superfici scorrono l'una sull'altra formando un contatto asciutto e incommensurabile. Questo effetto è stato previsto nel 1991, ma è stato misurato con precisione soltanto nel 2004 tra due superfici di grafite . Occorre notare che la somiglianza tra il termine superlubrificazione e termini come superconduttività e superfluidità è fuorviante; altri meccanismi di dissipazione possono portare a forze dissipative finite (in genere molto piccole). Una forza di attrito oltremodo piccola si può anche sperimentare quando un'asperitàscorre su una superficie piatta con una forza di carico inferiore a una certa soglia, dipendente dal potenziale di superficie avvertito dall'asperità e dalla rigidità dei materiali in contatto .Questa soglia può essere notevolmente aumentata eccitando le vibrazioni dell'asperità perpendicolari alla superficie di contatto,il che suggerisce un metodo pratico per limitare l'usura di sistemi nanoelettromeccanici (NEMS). (it) Supersmering (Engels: superlubricity) is een verschijnsel waarbij op atomaire schaal de wrijving tussen twee objecten (bijna) volledig verdwijnt. Het verschijnsel is al in 1990 voorspeld, maar pas in 2003 experimenteel waargenomen bij grafiet. (nl) 超润滑（Superlubricity）是指发生相对运动的物体间的摩擦力几乎为零甚至完全消失的现象。 即使在干摩擦条件下，当两个晶体表面间处于非公度（共度）态接触时，超润滑也可能发生，因此也称为结构超润滑。结构超润滑概念在1991年被提出，2004年在纳米石墨片之间获得实验证实。石墨中的碳原子以六边形的方式周期性排列，形成原子尺度的“峰-谷”景观，看上去就像生活中的鸡蛋托盘。当两个石墨表面处于公度态接触时（每旋转60度），两石墨表面间的摩擦力最大，当两石墨表面间发生相对旋转至非公度态接触时，摩擦力会极大地降低。这就像两个相互接触的鸡蛋托盘，当旋转使得它们不能互相“咬合”时，更容易发生相对滑动。 2012年，微米尺度的石墨超润滑现象通过微米石墨片的自缩回运动获得实验证实。最初对超润滑的研究受限于苛刻的实验条件，而通过自缩回运动研究石墨超润滑现象即使在微米尺度以及大气环境下也能稳定地、重复地实现，这使得超润滑现象有望在微机电系统（纳机电系统）中获得应用。 当一根针尖在平坦的表面滑行，并且所施加的载荷低于某一阈值时，也能实现超低摩擦状态。根据Tomlinson模型，该“超润滑”阈值与针尖-表面间的相互作用以及材料间的接触刚度密切相关。并且该阈值可以通过激发滑动系统的共振频率而显著降低，这揭示了一种可减少纳机电系统中磨损的方法。 需要指出的是，“超润滑”一词与“超导”，“超流”等名词的类似性具有一定的误导，因为其他能量耗散机制也可能导致有限的（通常很小）摩擦力。 (zh) |
| dbo:thumbnail | wiki-commons:Special:FilePath/Incommensurabilité_2.jpg?width=300 |
| dbo:wikiPageExternalLink | http://www.tribonet.org/brasenia-schreberi-mucilage-superlubric-biological-liquid/ http://www.tribonet.org/superlubricity-between-steel-surfaces-using-glycerolwater-mixture/ http://www.tribonet.org/superlubricity-by-means-of-repulsive-van-der-waals-forces/ |
| dbo:wikiPageID | 592513 (xsd:integer) |
| dbo:wikiPageLength | 10171 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1113010460 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:IBM_Mira dbr:Motion dbr:Nanotechnology dbr:Supercooling dbr:Nitinol dbr:Friction dbr:Physics dbc:Condensed_matter_physics dbr:Crystalline dbr:Superlens dbr:Brasenia dbr:Graphene dbr:Graphite dbr:Superconductivity dbr:Teflon dbr:Argonne_National_Laboratory dbr:LAMMPS dbr:Superfluid dbr:Hexagonal_crystal_family dbr:Tomlinson_model dbr:OpenMP dbr:Message_Passing_Interface dbr:Shearing_(physics) dbr:Super_black dbr:Giant_magnetoresistance dbr:Nanoelectromechanical_systems dbr:Superhard_material dbr:Tribology dbr:Friction_force_microscopy dbr:Resonance_frequency dbr:Superelasticity dbr:Unit_commensurability dbr:Diffraction_limit dbr:File:Incommensurabilité_2.jpg dbr:File:Incommensurabilité_4.jpg dbr:Structural_lubricity |
| dbp:wikiPageUsesTemplate | dbt:More_citations_needed_section dbt:Reflist dbt:Short_description |
| dcterms:subject | dbc:Condensed_matter_physics |
| gold:hypernym | dbr:Regime |
| rdf:type | yago:WikicatLubricants yago:Lubricant114890659 yago:Matter100020827 yago:PhysicalEntity100001930 dbo:Country yago:Substance100020090 |
| rdfs:comment | Supersmering (Engels: superlubricity) is een verschijnsel waarbij op atomaire schaal de wrijving tussen twee objecten (bijna) volledig verdwijnt. Het verschijnsel is al in 1990 voorspeld, maar pas in 2003 experimenteel waargenomen bij grafiet. (nl) Supraschmierfähigkeit (englisch: superlubricity) ist ein Phänomen, bei dem die Reibung fast vollständig verschwinden kann. Supraschmierfähigkeit tritt auf, wenn zwei kristalline Oberflächen zwar trocken, aber zueinander unpassend übereinander gleiten (siehe Inkommensurabilität aus dem Fachbereich der Kristallographie). Der Effekt wurde bereits 1991 postuliert, konnte aber erst 2004 mit großer Genauigkeit zwischen zwei Graphen-Oberflächen gemessen werden. Die Ähnlichkeit des Begriffs Supraschmierfähigkeit mit Begriffen wie Supraleitung und Suprafluidität ist irreführend, da diverse Verlustmechanismen zu endlichen (in der Regel kleinen) Reibungskräften führen können. (de) In physics (specifically tribology), superlubricity is a regime of motion in which friction vanishes or very nearly vanishes. What is a "vanishing" friction level is not clear, which makes the term quite vague. As an ad hoc definition, a kinetic coefficient of friction less than 0.01 can be adopted. This definition also requires further discussion and clarification. (en) Nel fenomeno della superlubrificazione l'attrito tra due superfici cristalline è pressoché nullo. La superlubrificazione ha luogo quando le superfici scorrono l'una sull'altra formando un contatto asciutto e incommensurabile. Questo effetto è stato previsto nel 1991, ma è stato misurato con precisione soltanto nel 2004 tra due superfici di grafite . Occorre notare che la somiglianza tra il termine superlubrificazione e termini come superconduttività e superfluidità è fuorviante; altri meccanismi di dissipazione possono portare a forze dissipative finite (in genere molto piccole). (it) 超润滑（Superlubricity）是指发生相对运动的物体间的摩擦力几乎为零甚至完全消失的现象。 即使在干摩擦条件下，当两个晶体表面间处于非公度（共度）态接触时，超润滑也可能发生，因此也称为结构超润滑。结构超润滑概念在1991年被提出，2004年在纳米石墨片之间获得实验证实。石墨中的碳原子以六边形的方式周期性排列，形成原子尺度的“峰-谷”景观，看上去就像生活中的鸡蛋托盘。当两个石墨表面处于公度态接触时（每旋转60度），两石墨表面间的摩擦力最大，当两石墨表面间发生相对旋转至非公度态接触时，摩擦力会极大地降低。这就像两个相互接触的鸡蛋托盘，当旋转使得它们不能互相“咬合”时，更容易发生相对滑动。 2012年，微米尺度的石墨超润滑现象通过微米石墨片的自缩回运动获得实验证实。最初对超润滑的研究受限于苛刻的实验条件，而通过自缩回运动研究石墨超润滑现象即使在微米尺度以及大气环境下也能稳定地、重复地实现，这使得超润滑现象有望在微机电系统（纳机电系统）中获得应用。 当一根针尖在平坦的表面滑行，并且所施加的载荷低于某一阈值时，也能实现超低摩擦状态。根据Tomlinson模型，该“超润滑”阈值与针尖-表面间的相互作用以及材料间的接触刚度密切相关。并且该阈值可以通过激发滑动系统的共振频率而显著降低，这揭示了一种可减少纳机电系统中磨损的方法。 (zh) |
| rdfs:label | Supraschmierfähigkeit (de) Superlubrificazione (it) Supersmering (nl) Superlubricity (en) 超润滑 (zh) |
| owl:sameAs | freebase:Superlubricity yago-res:Superlubricity wikidata:Superlubricity dbpedia-de:Superlubricity dbpedia-fa:Superlubricity dbpedia-fi:Superlubricity dbpedia-it:Superlubricity dbpedia-nl:Superlubricity dbpedia-zh:Superlubricity https://global.dbpedia.org/id/4zjUS |
| prov:wasDerivedFrom | wikipedia-en:Superlubricity?oldid=1113010460&ns=0 |
| foaf:depiction | wiki-commons:Special:FilePath/Incommensurabilité_2.jpg wiki-commons:Special:FilePath/Incommensurabilité_4.jpg |
| foaf:isPrimaryTopicOf | wikipedia-en:Superlubricity |
| is dbo:wikiPageWikiLink of | dbr:Carbon dbr:Allotropes_of_carbon dbr:Index_of_physics_articles_(S) dbr:Oil_additive dbr:Molybdenum_disulfide dbr:Friction dbr:Mira_(supercomputer) dbr:Graphite dbr:Lubricity dbr:Tomlinson_model dbr:Nanotribology dbr:Tribology |
| is foaf:primaryTopic of | wikipedia-en:Superlubricity |
