Thin Hydrocarbon and Water Films on Bare and Methylated Silica: Vapor Adsorption, Wettability, Adhesion, and Surface Forces

Langmuir ◽  
1995 ◽  
Vol 11 (5) ◽  
pp. 1701-1710 ◽  
Author(s):  
Luc J. M. Schlangen ◽  
Luuk K. Koopal ◽  
Martien A. Cohen Stuart ◽  
Johannes Lyklema ◽  
Michel Robin ◽  
...  
Keyword(s):  
Surface Forces ◽  
Vapor Adsorption ◽  
Water Films

RUBBER CONTACT PHENOMENA

2014 ◽  
Vol 87 (3) ◽  
pp. 383-416 ◽  
Author(s):  
Alan D. Roberts
Keyword(s):  
Salt Concentration ◽  
Friction Mechanisms ◽  
Sliding Friction ◽  
Liquid Films ◽  
Surface Forces ◽  
Thin Liquid Films ◽  
Water Films ◽  
Insight Into ◽  
Design Guidance ◽  
Strength Of Adhesion

ABSTRACT Research on rubber wiper blades led to the establishment of the now widely used Johnson, Kendall, Roberts (JKR) equilibrium equation that determines the strength of adhesion between surfaces. The equation was adapted to allow for the viscoelasticity of rubber, leading to explanations of how adhesion can impact on tack; rebound resilience; and rolling, static, and sliding friction. The adhesion of rubber to ice was found to depend on salt concentration in the ice, thus providing insight into winter tire performance. The development of optical techniques has greatly aided studies, particularly for measuring the thickness of thin liquid films sandwiched between rubber surfaces. Measurements on water films squeezed between rubber and glass revealed the action of repulsive surface forces that can reduce adhesion and friction. The efficacy of water lubrication depends upon whether surfactants are present and upon the acidity or alkalinity of the water. Improved understanding of adhesion and friction mechanisms offers design guidance for a range of rubber articles.

Forces between reactive surfaces

2021 ◽  
Author(s):  
Joanna Dziadkowiec ◽  
Bahareh Zareeipolgardani ◽  
Hsiu-Wei Cheng ◽  
Dag Kristian Dysthe ◽  
Anja Røyne ◽  
...  
Keyword(s):  
Colloidal Stability ◽  
Surface Reactivity ◽  
Surface Forces ◽  
Mineral Surfaces ◽  
Force Measurements ◽  
Surface Forces Apparatus ◽  
Water Films ◽  
Aqueous Salt Solutions ◽  
Macroscopic Deformation ◽  
Deformation Processes

<p>Adhesive and repulsive, nm-range surface forces acting between mineral grains control colloidal stability and mineral aggregation but less is known about how these forces are affected by surface reactivity and to what extent these grain-scale forces can influence various deformation processes in rocks. In this experimental work, we explore and quantify the surface forces acting between dynamic mineral surfaces that undergo recrystallization or are chemically reactive in contact with water or aqueous salt solutions. Our experimental setup consists of the surface forces apparatus (SFA) coupled with the multiple beam interferometry (MBI). This setup can excellently reproduce a typical grain contact geometry with nanometer-thin water films confined between contacting mineral grains over relatively large, micron-sized contact areas. Owing to the use of MBI, both surface growth or dissolution processes can be monitored during force measurements in real-time. As such, SFA can provide information about the links between surface reactivity and adhesive or repulsive surface forces. Using the examples of force measurements between recrystallizing or chemically reactive mineral surfaces such as carbonates, hydroxides, and silicates, we comment on the relationship between the measured surface forces and surface reactivity. We link our findings with the observed changes in mineral phases, surface topographies, or surface roughness. We also comment on how the micron-scale confinement in the SFA affects the growth and dissolution processes in contrast to less confined regions. The magnitude of the forces associated with dynamic mineral surfaces and the potential significance of these forces to macroscopic deformation processes and cohesion in rocks are discussed.</p>

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

scholarly journals Experimental Study on Activated Carbon-MIL-101(Cr) Composites for Ethanol Vapor Adsorption

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3811
Author(s):  
Zhongbao Liu ◽  
Jiayang Gao ◽  
Xin Qi ◽  
Zhi Zhao ◽  
Han Sun
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ethanol Vapor ◽  
Future Application ◽  
Working Fluid ◽  
Relative Pressure ◽  
Adsorption Refrigeration ◽  
Vapor Adsorption

In this study, the hydrothermal method was used to synthesize MIL-101(Cr), and activated carbon (AC) with different content was incorporated in to MIL-101(Cr), thereby obtaining AC-MIL-101(Cr) composite material with a huge specific surface area. The physical properties of MIL-101(Cr) and AC-MIL-101(Cr) were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption and desorption and specific surface area testing, and ethanol vapor adsorption performance testing. The results show that with the increase of activated carbon content, the thermal stability of AC-MIL-101(Cr) is improved. Compared with the pure sample, the BET specific surface area and pore volume of AC-MIL-101(Cr) have increased; In the relative pressure range of 0–0.4, the saturated adsorption capacity of AC-MIL-101(Cr) to ethanol vapor decreases slightly. It is lower than MIL-101(Cr), but its adsorption rate is improved. Therefore, AC-MIL-101(Cr)/ethanol vapor has a good application prospect in adsorption refrigeration systems. The exploration of AC-MIL-101(Cr) composite materials in this paper provides a reference for the future application of carbon-based/MOFS composite adsorbent/ethanol vapor working fluid in adsorption refrigeration.

scholarly journals Investigating the Ubiquitous Presence of Nanometric Water Films on Surfaces

2021 ◽  
Author(s):  
Sergio Santos ◽  
Carlo Alberto Amadei ◽  
Chia-Yun Lai ◽  
Tuza Olukan ◽  
Jin-You Lu ◽  
...  
Keyword(s):  
Water Films ◽  
Ubiquitous Presence

Thinning air–water films stabilized by bacterial particles

2021 ◽  
Author(s):  
Song Wu ◽  
Yuehua Yang ◽  
Hongyuan Jiang
Keyword(s):  
Water Films

Imaging the condensation and evaporation of molecularly thin ethanol films with surface forces apparatus

2014 ◽  
Vol 85 (1) ◽  
pp. 013702 ◽  
Author(s):  
Gutian Zhao ◽  
Qiyan Tan ◽  
Li Xiang ◽  
Di Zhang ◽  
Zhonghua Ni ◽  
...  
Keyword(s):  
Surface Forces ◽  
Surface Forces Apparatus
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