scholarly journals THE THEORETICAL RESPONSE OF LIVING CELLS TO CONTACT WITH SOLID BODIES

1922 ◽  
Vol 4 (4) ◽  
pp. 373-385 ◽  
Author(s):  
Wallace O. Fenn
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Solid Surface ◽  
Flat Surface ◽  
Living Cells ◽  
Point Of View ◽  
Solid Surfaces ◽  
Surface Tensions ◽  
Solid Bodies ◽  
Fluid Cell

The theoretical behavior of a hypothetical fluid cell in contact with flat and curved solid surfaces is discussed from the point of view of surface tension. An equation is derived for calculating the equilibrium position of the cell on a flat surface in terms of the surface tensions between the cell and the plasma, the plasma and the solid surface, and the solid surface and the cell. It is shown that the same equilibrium is predicted from consideration of the contact angle between the cell and the solid body. The relative surface energy has been calculated at various stages in the ingestion of a solid particle by a fluid cell four times as large in diameter, and it is thus shown that no particle will be ingested until the surface tensions are such that the cell would spread to infinity on a flat surface of the same substance. Here again the same equilibrium is predicted from considerations of the contact angle. The adhesiveness of blood cells to solid substances is shown to be a pure surface tension phenomenon, but in most reactions between living cells and solid bodies the fluidity of the protoplasm is also a factor of prime importance. The frequent occurrence of adhesiveness as a property of cells in contact with solid bodies is due in part to the fact that, by so adhering, the surface area of the cell not touching the solid is decreased.

Investigation of Bubble Nucleation on Platinum Solid Surface Using Molecular Dynamics (MD) Simulation

2010 ◽  
Author(s):  
S. M. Mirnouri Langroudi ◽  
M. Ghasemi ◽  
A. Shahabi ◽  
H. Rezaei Nejad
Keyword(s):  
Molecular Dynamics ◽  
Surface Tension ◽  
Contact Angle ◽  
Solid Surface ◽  
Bubble Radius ◽  
Pair Potential ◽  
Computer Code ◽  
Bubble Nucleation ◽  
Solid Surfaces ◽  
Density Profiles

The main purpose of this paper is to numerically investigate the contact angle of a bubble on a solid surface and the effect of bubble curvature on the surface tension. A computer code based on Molecular Dynamics method is developed. The code carries out a series of simulations to generate bubbles between two planar solid surfaces for different wettabilities. In our simulation, the surface wettability affects the bubble contact angle and curvature. The pair potential for the liquid–liquid and liquid-solid interaction is considered using Lennard-Jones model. Density profiles are locally calculated. Furthermore, surface tension is computed using Young-Laplace equation. It is observed that the gas pressure is independent of the bubble radius. However, the liquid pressure becomes more negative as the radius decreases. In addition, the amount of surface tension decreases by decrease of the radius.

Measurement of Burst Pressure of Capillary Burst Valve

2010 ◽  
Author(s):  
Hong Chen ◽  
Toru Yamada ◽  
Mohammad Faghri
Keyword(s):  
Surface Tension ◽  
Solid Surface ◽  
Burst Pressure ◽  
Surface Tensions ◽  
Fluid Surface ◽  
Mechanical Components

Capillary burst valve (CBV), a counterpart to an elastomeric diaphragm microvalve, handles fluid in microchannels by capillarity. Thus, it avoids integration of mechanical components. We experimentally estimated the burst pressure, beyond which CBV cannot hold fluid, using fluids with distinct surface tensions in CBVs grafted with distinct surface constitutions in microchannels. We found that both the fluid surface tension and the solid surface constitution influence the burst pressure. The burst pressure reduces more significantly under the influence of the fluid surface tension.

scholarly journals Sorting Liquid Droplets by Surface Tension Using Devices with Quasi-Superamphiphobic Coatings

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 820 ◽  
Author(s):  
Yu-Ping Zhang ◽  
Di Fan ◽  
Xiu-Zhi Bai ◽  
Cheng-Xing Cui ◽  
Jun Chen ◽  
...  
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Solid Surface ◽  
Glass Slide ◽  
Liquid Droplets ◽  
Surface Tensions ◽  
Coated Nanoparticles ◽  
Tilting Angle ◽  
Time Distance ◽  
Alcoholic Strength

Any solid surface with homogenous or varying surface energy can spontaneously show variable wettability to liquid droplets with different or identical surface tensions. Here, we studied a glass slide sprayed with a quasi-superamphiphobic coating consisting of a hexane suspension of perfluorosilane-coated nanoparticles. Four areas on the glass slide with a total length of 7.5 cm were precisely tuned via ultraviolet (UV) irradiation, and droplets with surface tensions of 72.1–33.9 mN m−1 were categorized at a tilting angle of 3°. Then, we fabricated a U-shaped device sprayed with the same coating and used it to sort the droplets more finely by rolling them in the guide groove of the device to measure their total rolling time and distance. We found a correlation between ethanol content/surface tension and rolling time/distance, so we used the same device to estimate the alcoholic strength of Chinese liquors and to predict the surface tension of ethanol aqueous solutions.

Some remarks on the solid surface tension determination from contact angle measurements

2017 ◽  
Vol 405 ◽  
pp. 88-101 ◽  
Author(s):  
Anna Zdziennicka ◽  
Katarzyna Szymczyk ◽  
Joanna Krawczyk ◽  
Bronisław Jańczuk
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Solid Surface ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Solid Surface Tension

The Effect of Solid Surface Roughness on Dynamic Contact Angles in Solid-Liquid-Liquid Systems

2002 ◽  
Author(s):  
Dandina N. Rao ◽  
Hussain H. Radwani
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Solid Surface ◽  
Water System ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Solid Surfaces ◽  
Liquid Systems ◽  
L Systems ◽  
Solid Liquid

The engineering applications of spreading and adhesion phenomena involving fluids on solids are numerous. The adhesive and spreading interactions at the solid-fluid interfaces are well characterized by dynamic contact angles. This study reports on the results of an experimental investigation into the effect of solid surface roughness on dynamic contact angles in solid-liquid-liquid (S-L-L) systems. The experiment involved the use of Wilhelmy Plate apparatus to measure adhesion tension (which is the product of interfacial tension and cosine of the contact angle between the liquid-liquid interface and the solid surface), the DuNuoy tensiometer to measure the liquid-liquid interfacial tension, and a profilometer to characterize the roughness of the solid surfaces used. The components of the solid-liquid-liquid systems studied consisted of: (i) smooth glass, roughened quartz and an actual rock surface for the solid phase, (ii) normal-hexane and deionized water as the two immiscible liquid phases. The dynamic contact angles (advancing and receding angles) of the three-phase (rock-oil-water) system provide essential information about the wettability of petroleum resrvoirs. The wettability of a reservoir is an important parameter that affects oil recovery in primary, secondary, and enhanced recovery operations [1]. Contact angle measurements on smooth surfaces are generally used to characterize reservoir wettability. However pore surfaces within reservoir rocks are essentially rough and hence it is important to determine the effect of such roughness on measured contact angles. There is very little information in the open literature on the effect of surface roughness on dynamic contact angles in S-L-L systems. In the present work, four levels of roughness of solid surfaces of similar mineralogy (quartz and glass) were tested in hexane-deionized water fluid pair. The advancing and receding contact angles measured at ambient conditions were analyzed for wettability effects. It was found that as surface roughness increased, the dynamic contact angles also increased. The wettability of the rock-oil-water system shifted from weakly water-wet for the smooth glass to intermediate-wet for the roughened surface. The general trends observed in our study were found to be in good agreement with other published results. However, the generally held notion of increasing contact angle hysteresis with increasing roughness appears to be incorrect in solid-liquid-liquid systems.

On the Thermocapillary Migration at the Liquid and Solid Aspects

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Yajuan Ji ◽  
Qingwen Dai ◽  
Wei Huang ◽  
Xiaolei Wang
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Solid Surfaces ◽  
Interfacial Phenomenon ◽  
Loss Mechanism ◽  
Thermocapillary Migration ◽  
Migration Mechanism ◽  
Migration Capacity ◽  
External Forces ◽  
Very High

Thermocapillary migration is an interfacial phenomenon that describes liquid flow on a nonisothermal surface from warm to cold regions in the absence of external forces. It is a typical lubricant loss mechanism in tribosystems. To ensure continued reliability of lubricated assemblies, knowledge of the migration capacity of different liquids and solids is needed. In the present work, migration experiments were conducted on various liquid lubricants on different solid surfaces. It was found that polar lubricants such as ionic liquids and polyethylene glycol hardly migrate on the tested surfaces, and the antimigration capacity of the polytetrafluoroethylene surface was discovered to be very high. Particular attention is paid to the migration mechanism associated with surface tension and contact angle. General guidelines for evaluating the migration capacities of different liquids on solids are proposed.

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