Mass transport of SDS and AOT solutions during a rapid surface expansion: Relaxation of surface tension

2020 ◽  
Vol 108 ◽  
pp. 23-28
Author(s):  
Shi-Yow Lin ◽  
Ruey-Yug Tsay ◽  
Ya-Chi Lin ◽  
Siam Hussain
Keyword(s):  
Surface Tension ◽  
Mass Transport ◽  
Surface Expansion

Photoisomerization-induced patterning of ion-pairing materials based on anionic azobenzene and its complex with a fluorescent π-electronic system

2021 ◽  
Vol 57 (35) ◽  
pp. 4287-4290
Author(s):  
Ryohei Yamakado ◽  
Issei Kitamura ◽  
Mitsuo Hara ◽  
Shusaku Nagano ◽  
Takahiro Seki ◽  
...  
Keyword(s):  
Surface Tension ◽  
Mass Transport ◽  
Trace Amount ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Electronic System ◽  
Large Mass ◽  
System P ◽  
The Difference

Large mass transport driven by the difference in the photoisomerization-induced surface tension was demonstrated in ion pairs, enabling fluorescence patterning using a trace amount of photoisomerized anions in complexation with a π-electronic system.

Convection in Pulsed Laser Formed Melts

1980 ◽  
Vol 1 ◽  
Author(s):  
G. E. Possin ◽  
H. G. Parks ◽  
S. W. Chiang
Keyword(s):  
Surface Tension ◽  
Approximate Solution ◽  
Mass Transport ◽  
Stokes Equation ◽  
Pulsed Laser ◽  
Metal Films ◽  
Navier Stokes ◽  
Mixing Times ◽  
Navier Stokes Equation ◽  
Theoretical Considerations

ABSTRACTIn this paper we treat surface tension driven convection effects in pulsed laser formed melts. Mass transport is determined from an approximate solution of the Navier Stokes equation. It is shown that for small laser spot diameters the characteristic mixing times are on the order of 100's of ns. The dependence of the convection mechanism on material and laser parameters is discussed and extended to thin metal films on Si. Experimental results substantiating the theoretical considerations are presented.

Experimental Studies of Nonisothermal Binary Fluids With Phase Change in Confined Geometries

2012 ◽  
Author(s):  
Yaofa Li ◽  
Benjamin M. Chan ◽  
Minami Yoda
Keyword(s):  
Surface Tension ◽  
Mass Transport ◽  
Phase Change ◽  
Experimental Studies ◽  
Liquid Density ◽  
Binary Fluids ◽  
Vapor Interface ◽  
Evaporation And Condensation ◽  
Alcohol Water ◽  
Liquid Vapor

Evaporative cooling, which exploits the large latent heats associated with phase change, is of interest in a variety of thermal management technologies. Yet our fundamental understanding of thermal and mass transport remains limited. Evaporation and condensation can change the local temperature, and hence surface tension, along a liquid-vapor interface. The resulting thermocapillary stresses are dominant at small length scales in many cases. For the vast majority of single-component coolants, surface tension decreases as temperature increases, resulting in thermocapillary stresses that drive the liquid away from hot regions, leading to dryout, for example. The direction of flow driven by thermocapillary stresses is therefore consistent with that driven by buoyancy effects due to changes in the liquid density with temperature. However, a number of binary “self-rewetting fluids,” consisting of water-alcohol mixtures, have surface tensions that increase with temperature, leading to thermocapillary stresses that drive liquid towards hot regions, improving cooling performance. Although not all binary coolants are self-rewetting, all such coolants are subject to solutocapillary stresses, where differential evaporation of the two fluid components leads to changes in local species concentration at the liquid-vapor interface, and hence in surface tension. Given the lack of general models of thermal and mass transport in nonisothermal two-phase flows, experimental studies of convection in simple fluids and binary alcohol-water mixtures due to evaporation and condensation driven by a horizontal temperature gradient were performed. In these initial studies, both the simple and binary fluids have thermocapillary stresses that drive liquid away from hot regions. However, the binary fluid also has solutocapillary stresses that drive liquid towards hot regions. Particle-image velocimetry (PIV) is used to nonintrusively measure the velocity and temperature fields in a layer of liquid a few mm in depth in a 1 cm × 1 cm × 4.85 cm sealed and evacuated cuvette heated on one end and cooled on the other end.

Influence of Super Hydrophobic Modification on Protective Performance of PTFE Micropore Membrane

2012 ◽  
Vol 627 ◽  
pp. 726-729
Author(s):  
Xin Min Hao ◽  
Yuan Yang ◽  
Xin Xing Feng ◽  
Fei Wang
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Modification ◽  
Protective Property ◽  
Membrane Surface ◽  
Mustard Gas ◽  
Hydrophobic Modification ◽  
Protective Material ◽  
Surface Expansion ◽  
Protective Performance

Using self - prepared fluorochemical surfactant, PTFE micropore membrane was modified to improve its hydrophobicity. The surface morphology of the membrane was observed by SEM and its Contact angle was determined by. The protective property of the membranes against mustard gas was evaluated using the break-through test. The result shows that, the thesis put forward a novel BC protection idea that through membrane surface modification the poisonous agent can be rolled into liquid spheres and slided away from the membrane surface automatically because of the low surface tension of the membrane, which stands out from the traditional methodology by quick poisonous agent surface expansion and evaporation on the surface of the BC protective material.

Models of Thermodynamic Properties of Prominences

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey
Keyword(s):  
Thermodynamic Properties ◽  
Mass Transport ◽  
Emission Spectrum ◽  
Thermodynamic Parameters ◽  
Working Group ◽  
Physical Processes ◽  
Theoretical Concepts ◽  
Group 3 ◽  
Observational Techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

The Use of Styrenes as Embedding Media for Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 488-489
Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Surface Tension ◽  
Ultraviolet Light ◽  
Methyl Ethyl Ketone Peroxide ◽  
Methyl Ethyl ◽  
Styrene Polymerization ◽  
Radical Initiation ◽  
Tertiary Butyl ◽  
Low Viscosity ◽  
Free Radical Initiation

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.

The nucleation of cavities at grain boundaries

1987 ◽  
Vol 45 ◽  
pp. 288-291
Author(s):  
P. J. Goodhew
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Grain Boundaries ◽  
Radiation Damage ◽  
Impurity Concentration ◽  
Driving Force ◽  
Nucleation And Growth ◽  
Phase Boundaries ◽  
Cavity Nucleation ◽  
Spherical Bubble

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.

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