scholarly journals Evaluation of Vapor Pressure and Ultra-High Vacuum Tribological Properties of Ionic Liquids (2) Mixtures and Additives

2008 ◽  
Author(s):  
Wilfredo Morales ◽  
Kenneth W. Street ◽  
Victor R. Koch ◽  
Ryan M. Richard
Keyword(s):  
Ionic Liquids ◽  
Vapor Pressure ◽  
Tribological Properties ◽  
High Vacuum ◽  
Degradation Pathway ◽  
Ultra High Vacuum ◽  
Vapor Pressures ◽  
Ambient Conditions ◽  
Raman Analysis ◽  
Vapor Pressure Measurements

Ionic liquids are salts, many of which are typically viscous fluids at room temperature. The fluids are characterized by negligible vapor pressures under ambient conditions. These properties have led us to study the effectiveness of ionic liquids containing both organic cations and anions for use as space lubricants. In the previous paper we have measured the vapor pressure and some tribological properties of two distinct ionic liquids under simulated space conditions. In this paper we will present vapor pressure measurements for two new ionic liquids and friction coefficient data for boundary lubrication conditions in a spiral orbit tribometer using stainless steel tribocouples. In addition we present the first tribological data on mixed ionic liquids and an ionic liquid additive. Post mortem infrared and Raman analysis of the balls and races indicates the major degradation pathway for these two organic ionic liquids is similar to those of other carbon based lubricants, i.e. deterioration of the organic structure into amorphous graphitic carbon. The coefficients of friction and lifetimes of these lubricants are comparable to or exceed these properties for several commonly used space oils.

Evaluation of Vapor Pressure and Ultra-High Vacuum Tribological Properties of Ionic Liquids

2011 ◽  
Vol 54 (6) ◽  
pp. 911-919 ◽  
Author(s):  
Kenneth W. Street ◽  
Wilfredo Morales ◽  
Victor R. Koch ◽  
Daniel J. Valco ◽  
Ryan M. Richard ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Vapor Pressure ◽  
Tribological Properties ◽  
High Vacuum ◽  
Ultra High Vacuum

Laser cleaning of exfoliated graphene

2012 ◽  
Vol 1455 ◽  
Author(s):  
Oliver Ochedowski ◽  
Benedict Kleine Bußmann ◽  
Marika Schleberger
Keyword(s):  
Local Heating ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ambient Conditions ◽  
Kelvin Probe ◽  
Structural Modifications ◽  
Force Microscopy ◽  
Exfoliated Graphene ◽  
Atomic Force ◽  
P Type

ABSTRACTWe have employed atomic force and Kelvin-Probe force microscopy to study graphene sheets exfoliated on TiO2 under the influence of local heating achieved by laser irradiation. Exfoliation and irradiation took place under ambient conditions, the measurements were performed in ultra high vacuum. We show that after irradiation times of 6 min, an increase of the surface potential is observed which indicates a decrease of p-type carrier concentration. We attribute this effect to the removal of adsorbates like water and oxygen. After irradiation times of 12 min our topography images reveal severe structural modifications of graphene. These resemble the nanocrystallite network which form on graphene/SiO2 but after much longer irradiation times. From our results we propose that short laser heating at moderate powers might offer a way to clean graphene without inducing unwanted structural modifications.

Ionic Liquids Studied at Ultra-High Vacuum

2012 ◽  
pp. 251-282
Author(s):  
Kevin R. J. Lovelock ◽  
Peter Licence
Keyword(s):  
Ionic Liquids ◽  
High Vacuum ◽  
Ultra High Vacuum

scholarly journals Spatial mapping of optical modes in plasmonic nanoantenna by scanning tunneling microscopy

2021 ◽  
Vol 2015 (1) ◽  
pp. 012139
Author(s):  
V A Shkoldin ◽  
D V Lebedev ◽  
A M Mozharov ◽  
D V Permyakov ◽  
L N Dvoretckaia ◽  
...  
Keyword(s):  
Near Field ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Inelastic Electron ◽  
Ambient Conditions ◽  
Tunneling Microscopy ◽  
Theoretical Predictions ◽  
Optical Modes ◽  
On Chip

Abstract Using of inelastic electron tunnelling is very promising approach to study of subwavelength photons and plasmons sources. Such sources are very important for improving of on-chip data processing. One of the ways for development of efficient and compact optical electrically-driven sources is using of nanoantenna placed into the tunnel junction. In this work, singe optical nanoantenna was investigated under ultra-high vacuum and ambient conditions. Photon maps of nanoantenna excited under scanning tunnel microscope tip was observed and the obtained results was compared with the theoretical predictions of electromagnetic near-field distribution.

Fluorescence resonance energy transfer of gas-phase ions under ultra high vacuum and ambient conditions

2014 ◽  
Vol 16 (19) ◽  
pp. 8911-8920 ◽  
Author(s):  
Vladimir Frankevich ◽  
Vitaliy Chagovets ◽  
Fanny Widjaja ◽  
Konstantin Barylyuk ◽  
Zhiyi Yang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Gas Phase ◽  
Fluorescence Resonance Energy Transfer ◽  
High Vacuum ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Ultra High Vacuum ◽  
Ambient Conditions ◽  
Gas Phase Ions ◽  
Fluorescence Resonance

Influences of Gases on the Tribological Properties of Pure Iron

2011 ◽  
Author(s):  
Kanao Fukuda ◽  
Joichi Sugimura
Keyword(s):  
Tribological Properties ◽  
Dry Friction ◽  
Pure Iron ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
The Other ◽  
Vacuum Vessel ◽  
Friction Coefficients ◽  
Wear Rates ◽  
Pin On Disk

In this study, trace oxygen and water as impurities in experimental gas environments were reduced to less than 10 ppb to eliminate their influences on the tribological properties. A pin-on-disk apparatus in an ultra-high vacuum vessel equipped with a gas filtering system enabled pure experimental gas environments. Dry friction tests clarified that the tribological properties of pure iron in ultra-high vacuum and argon were similar to each other. On the other hand, friction coefficients obtained in hydrogen and nitrogen were considerably lower than those obtained in ultra-high vacuum and argon. Specific wear rates of pin and disk were close to each other in ultra-high vacuum, argon and hydrogen while those took very different values in nitrogen. Hydrogen influenced the tribological properties of pure iron to some extent but the influences were not as much as that of nitrogen.

scholarly journals Principles of molecular assemblies leading to molecular nanostructures

2013 ◽  
Vol 371 (2000) ◽  
pp. 20120304 ◽  
Author(s):  
Kunal S. Mali ◽  
Steven De Feyter
Keyword(s):  
Self Assembly ◽  
Contemporary Literature ◽  
High Vacuum ◽  
Building Blocks ◽  
Ultra High Vacuum ◽  
Two Dimensional ◽  
Ambient Conditions ◽  
Solid Interface ◽  
Metal Organic ◽  
Molecular Nanostructures

Self-assembled physisorbed monolayers consist of regular two-dimensional arrays of molecules. Two-dimensional self-assembly of organic and metal–organic building blocks is a widely used strategy for nanoscale functionalization of surfaces. These supramolecular nanostructures are typically sustained by weak non-covalent forces such as van der Waals, electrostatic, metal–ligand, dipole–dipole and hydrogen bonding interactions. A wide variety of structurally very diverse monolayers have been fabricated under ambient conditions at the liquid–solid and air–solid interface or under ultra-high-vacuum (UHV) conditions at the UHV–solid interface. The outcome of the molecular self-assembly process depends on a variety of factors such as the nature of functional groups present on assembling molecules, the type of solvent, the temperature at which the molecules assemble and the concentration of the building blocks. The objective of this review is to provide a brief account of the progress in understanding various parameters affecting two-dimensional molecular self-assembly through illustration of some key examples from contemporary literature.

Tribological investigations of ionic liquids in ultra-high vacuum environment

2013 ◽  
Vol 26 (7-8) ◽  
pp. 514-524 ◽  
Author(s):  
Vladimir Totolin ◽  
Marcello Conte ◽  
Edurne Berriozábal ◽  
Francesco Pagano ◽  
Ichiro Minami ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Vacuum Environment

Activities from vapor pressure measurements of lithium and of sodium chlorates in water and water–dioxane solvents

1969 ◽  
Vol 47 (14) ◽  
pp. 2671-2680 ◽  
Author(s):  
A. N. Campbell ◽  
B. G. Oliver
Keyword(s):  
Vapor Pressure ◽  
Activity Coefficients ◽  
Sodium Chlorate ◽  
Differential Manometer ◽  
Pressure Measurements ◽  
Vapor Pressures ◽  
Hydration Numbers ◽  
Water Solutions ◽  
Experimental Activity ◽  
Vapor Pressure Measurements

The vapor pressures of solutions of sodium chlorate and of lithium chlorate in water and in solvents consisting of 44.5% dioxane–55.5% water and of 64.5% dioxane–35.5% water, at 25 °C, were determined using a differential manometer. The vapor compositions of the dioxane–water solutions were found by the air-saturation method.The mean molal activity coefficients were calculated from the vapor pressures and compositions. The activity coefficients of the solute were fitted to the theoretical equations of Stokes and Robinson and of Glueckauf, yielding hydration numbers for the cations of the salts.The minimum dioxanation numbers of sodium and of lithium chlorates in the dioxane–water mixtures were calculated from the experimental activity coefficients by the method of Grunwald. The results show that lithium chlorate is more highly solvated than sodium chlorate and that dioxane plays a major role in the solvation of both electrolytes in the dioxane–water mixtures.

Sign in / Sign up

Export Citation Format

Share Document