دورية أكاديمية
Transition from static to kinetic friction in a model lubricated system
| العنوان: | Transition from static to kinetic friction in a model lubricated system |
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| المساهمون: | Demirel, Adem Levent (ORCID 0000-0002-1809-1575 & YÖK ID 6568), Granick, S., College of Sciences, Department of Chemistry |
| المصدر: | Journal of Chemical Physics |
| بيانات النشر: | American Institute of Physics (AIP) Publishing International |
| سنة النشر: | 1998 |
| المجموعة: | Koç University Suna Kıraç Library’ Digital Collections |
| مصطلحات موضوعية: | Chemistry, Physics, Anomalous rheological behavior, Block-copolymers, Confined liquids, Boundary lubrication, Wormlike micelles, Ordered phases, Shear, Films, Slip, Stick |
| الوصف: | Molecularly thin confined fluids were deformed in shear faster than structural relaxations in response to shear could be accomplished, such that with increasing deformation the systems passed from the rest state to sliding. The response of these systems-two atomically smooth mica sheets separated by a fluid comprised of globularly shaped molecules [octamethylcyclotetrasiloxane]-was studied as a function of film thickness of the fluid (from 80 to 10 Angstrom, i.e, from similar to 8 to similar to 1 molecular dimensions), as a function of normal pressure, and as a function of deformation rate, using a modified surface forces apparatus. Whereas the linear response was always liquid-like provided that the deformation rate was sufficiently slow, a "stick-slip" transition from the rest state to sliding was observed when the deformation rate was large, provided that the oscillatory frequency sufficiently exceeded the inverse intrinsic relaxation time of the confined fluid. This transition was monotonic and reversible without hysteresis for relatively thick films but for thinner films was discontinuous with hysteresis. For films thicker than 3 molecular layers (ML), two length scales in deformation were observed; the films showed nonlinear force-deformation response beginning at a deformation amplitude of 3 iq but in general showed stick slip only when the deformation was larger than this. The critical deformation at the point of stick slip decreased from 9 to 3 Angstrom with increasing normal pressure, indicating diminished plasticity of the confined structures with increasing normal pressure. The critical film thickness of 3 ML correlates with the possibility of one rather than more slip planes. The thinnest films under the highest compressive pressures showed moderate increase of the viscous shear force with increasing effective sliding velocity, but in general the viscous force reached a plateau in which force showed almost no dependence on sliding rate. In interpreting the results in the context of friction, static ... |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | |
| اللغة: | English |
| تدمد: | 0021-9614 |
| العلاقة: | Publisher version; Koç University Institutional Repository; Demirel, A. L., and S. Granick. "Transition from Static to Kinetic Friction in a Model Lubricated System." Journal of Chemical Physics 109.16 (1998): 6889-97.; https://doi.org/10.1063/1.477256Test; IR00971; WoS; Scopus; NA; http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/975Test |
| DOI: | 10.1063/1.477256 |
| الإتاحة: | https://doi.org/10.1063/1.477256Test http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/975Test |
| رقم الانضمام: | edsbas.C64529E |
| قاعدة البيانات: | BASE |
| تدمد: | 00219614 |
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| DOI: | 10.1063/1.477256 |