Measurement of the Equilibrium Contact Angle of Wetting as a Method of Studying the State of the Surface Energy at the Solid–Liquid–Gas Interface

The article uses the thermodynamics of interfacial phenomena to justify the fact that Young’s equations can correctly describe the three-phase equilibrium with any type of interatomic bonds. Wetting, adhesion, dissolution, surface adsorption, and other surface phenomena are important characteristics, whichlargely determine the quality and durability of materials, and the development of a number of production techniques, including welding, soldering, baking of metallic and non-metallic powders, etc. Therefore, it is important to study them.Using experimental data regarding surface energies of liquids (melts) and contact angles available in the literature, we calculated the surface energies of many solid metals, oxides, carbides, and other inorganic and organic materials without taking into account the amount of the interfacial energy at the solid-liquid (melt) interface. Some researchers assumed that in case of an acute contact angle the interfacial energy is low. Therefore, they neglected it and assumed it to be zero.Others knew that this value could not be measured, that is why they measured and calculated the difference between the surface energy of a solid and the interfacial energy of a solid and a liquid (melt), which is equal to the product of the surface energy of this liquid by the cosine of the contact angle. It is obvious that these methods of determining the surface energy based on such oversimplified assumptions result in poor accuracy.Through the use of examples this paper shows how the surface energies of solids were previously calculated and how the shortcomings of previous calculations can be corrected

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MODELLING AND INVESTIGATION OF THE DEPENDENCE OF SUPERHYDROPHOBIC PROPERTIES OF NANOSURFACES ON THE TOPOLOGY OF MICROCHANNELS

Environment Technology Resources Proceedings of the International Scientific and Practical Conference ◽

10.17770/etr2019vol3.4171 ◽

2019 ◽

Vol 3 ◽

pp. 52

Author(s):

Sharif E. Guseynov ◽

Jekaterina V. Aleksejeva

Keyword(s):

Contact Angle ◽

Interphase Boundary ◽

Slip Length ◽

Superhydrophobic Surfaces ◽

Equilibrium Contact Angle ◽

Three Phase ◽

Quantitative Understanding ◽

Air Cushion ◽

Local Slip ◽

Solid Liquid

In the Cassie-Baxter state anisotropic superhydrophobic surfaces have high lubricating properties. Such superhydrophobic surfaces are used in medical implants, aircraft industry, vortex bioreactors etc. In spite of the fact that quantitative understanding of fluid dynamics on anisotropic superhydrophobic surfaces has been broadened substantially for last several years, there still are some unsolved problems in this field. This work investigates dynamics of a liquid on unidirectional superhydrophobic surfaces in the Cassie-Baxter state, when surface texture is filled with gas and, consequently, the liquid virtually is located on some kind of an air cushion. Energy of the interphase boundary liquid-gas is much smaller than energy of the interphase boundary solid-liquid, that is why the contact angle at wetting such surfaces differs a lot from the Young contact angle and depends on contact area ratio of liquid-gas and liquid-solid in visible contact of liquid and surface. Considering difference in energy obtained if we slightly shift the three-phase contact line, expression for macroscopic equilibrium contact angle, which describes the Cassie-Baxter state, can be deduced. In the work the design formula for computing local-slip length profiles of liquid on the considered superhydrophobic surfaces is obtained.

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Effect of Ionizing Beta Radiation on the Strength of Bonded Joints of Polycarbonate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1025-1026.251 ◽

2014 ◽

Vol 1025-1026 ◽

pp. 251-255 ◽

Cited By ~ 2

Author(s):

Martin Bednarik ◽

David Manas ◽

Miroslav Manas ◽

Michal Stanek ◽

Jan Navratil ◽

...

Keyword(s):

Contact Angle ◽

Surface Energy ◽

Adhesive Bonding ◽

Lower Surface ◽

Beta Radiation ◽

Bonded Joints ◽

Adhesive Properties ◽

Adhesion Properties ◽

Measurement Results ◽

Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polycarbonate. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 50 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

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Strength of Bonded Joints of Linear Low – Density Polyethylene after Radiation Cross – Linking

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1025-1026.615 ◽

2014 ◽

Vol 1025-1026 ◽

pp. 615-620 ◽

Cited By ~ 2

Author(s):

Martin Bednarik ◽

David Manas ◽

Miroslav Manas ◽

Michal Stanek ◽

Jan Navratil ◽

...

Keyword(s):

Contact Angle ◽

Surface Energy ◽

Adhesive Bonding ◽

Beta Radiation ◽

Low Density Polyethylene ◽

Low Density ◽

Bonded Joints ◽

Linear Low Density Polyethylene ◽

Adhesion Properties ◽

Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of linear low – density polyethylene (LLDPE). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of linear low – density polyethylene. Bonded surfaces with ionizing beta radiation doses of 0, 66, 132 and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 132 kGy by which the highest surface energy and the highest strength of bonded joints of LLDPE were achieved. The strength of bonded joints after irradiation was increased up to 60 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

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Contact Angle for Spherical Nanodroplet in Cylindrical Cavity with Quadratic Curve Generatrix

Mechanical Engineering Research ◽

10.5539/mer.v6n1p96 ◽

2016 ◽

Vol 6 (1) ◽

pp. 96

Author(s):

Ai-Jun Hu ◽

Bao-Zhan Lv

Keyword(s):

Contact Angle ◽

Line Tension ◽

Equilibrium Contact Angle ◽

Cylinder Surface ◽

Quadratic Curve ◽

Dividing Surface ◽

Solid Liquid ◽

Young Equation ◽

Homogeneous Cylinder ◽

Young's Equation

<p class="1Body">Wetting of a spherical nanodroplet in smooth and homogeneous cylinder surface rotated by quadratic curve was studied by methods of thermodynamics. The solid-liquid-vapor system was separated into six parts using Gibbs method of dividing surface. The system free energy was calculated. A generalized Young equation for the equilibrium contact angle is proposed taking the line tension effects into consideration. On the basis of some assumptions, this generalized Young equation is the same as the classical Young’s equation.</p>

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Effect of Nanostructures and Wettability on the Instability of Thin Water Films on a Solid Surface: A Molecular Dynamics Study

ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2016-7921 ◽

2016 ◽

Author(s):

Liyong Sun ◽

Jun Zhou ◽

Phil Jones

Keyword(s):

Molecular Dynamics ◽

Contact Angle ◽

Film Thickness ◽

Energy Parameter ◽

Gold Surface ◽

Equilibrium Contact Angle ◽

Droplet Spreading ◽

Water Films ◽

Critical Film Thickness ◽

Solid Liquid

Molecular dynamics simulations are performed to investigate the stability of thin water films on square gold nanostructures of varying depth and wavelength. The critical film thickness of breakup is shown to increase linearly with nanostructure depth, and is not affected by nanostructure wavelength. In addition, the wettability of the gold surface is controlled from superhydrophilic to hydrophobic by altering the energy parameter of the solid-liquid potential, and the equilibrium contact angle for each energy parameter is calculated using a droplet spreading simulation. Four different energy parameters of the solid-liquid potential are investigated. The ratio of the energy parameter to the energy parameter of water and gold is 1, 0.5, 0.25 and 0.1. The case for ratio of 1 represents water on superhydrophilic gold surfaces. The relationship between the critical film thickness of breakup and the equilibrium contact angle is demonstrated. The results of the present work will provide guidelines for nanostructure design for controlling thin film stability.

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Wetting of glass surface using natural surfactants

Micro and Nanosystems ◽

10.2174/1876402912666200219111447 ◽

2020 ◽

Vol 12 ◽

Author(s):

Nihar Ranjan Biswal

Keyword(s):

Contact Angle ◽

Glass Surface ◽

Pure Water ◽

Amyl Alcohol ◽

Synthetic Surfactant ◽

Wide Range ◽

Different Types ◽

Natural Surfactants ◽

Triton X ◽

Solid Liquid

Background: Surfactant adsorption at the interfaces (solid–liquid, liquid–air, or liquid–liquid) is receiving considerable attention from a long time due to its wide range of practical applications. Objective: Specifically wettability of solid surface by liquids is mainly measured by contact angle and has many practical importances where solid–liquid systems are used. Adsorption of surfactants plays an important role in the wetting process. The wetting behaviours of three plant-based natural surfactants (Reetha, Shikakai, and Acacia) on the glass surface are compared with one widely used nonionic synthetic surfactant (Triton X-100) and reported in this study. Methods: The dynamic contact angle study of three different types of plant surfactants (Reetha, Shikakai and Acacia) and one synthetic surfactant (Triton X 100) on the glass surface has been carried out. The effect of two different types of alcohols such as Methanol and amyl alcohol on wettability of shikakai, as it shows little higher value of contact angle on glass surface has been measured. Results: The contact angle measurements show that there is an increase in contact angle from 47° (pure water) to 67.72°, 65.57°, 68.84°, and 68.79° for Reetha, Acacia, Shikakai, and Triton X-100 respectively with the increase in surfactant concentration and remain constant at CMC. The change in contact angle of Shikakai-Amyl alcohol mixtures are slightly different than that of methanol-Shikakai mixture, mostly there is a gradual increase in contact angle with the increasing in alcohol concentration. Conclusion: There is no linear relationship between cos θ and inverse of surface tension. There was a linear increase in surface free energy results with increase in concentration as more surfactant molecules were adsorbing at the interface enhancing an increase in contact angle.

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Mechanism of active silica nanofluids based on interface-regulated effect during spontaneous imbibition

Petroleum Science ◽

10.1007/s12182-020-00537-8 ◽

2021 ◽

Author(s):

Xu-Guang Song ◽

Ming-Wei Zhao ◽

Cai-Li Dai ◽

Xin-Ke Wang ◽

Wen-Jiao Lv

Keyword(s):

Contact Angle ◽

Interfacial Tension ◽

Oil Recovery ◽

Dynamic Contact Angle ◽

Liquid Interface ◽

Spontaneous Imbibition ◽

Wettability Alteration ◽

Low Permeability ◽

Oil Water ◽

Solid Liquid

AbstractThe ultra-low permeability reservoir is regarded as an important energy source for oil and gas resource development and is attracting more and more attention. In this work, the active silica nanofluids were prepared by modified active silica nanoparticles and surfactant BSSB-12. The dispersion stability tests showed that the hydraulic radius of nanofluids was 58.59 nm and the zeta potential was − 48.39 mV. The active nanofluids can simultaneously regulate liquid–liquid interface and solid–liquid interface. The nanofluids can reduce the oil/water interfacial tension (IFT) from 23.5 to 6.7 mN/m, and the oil/water/solid contact angle was altered from 42° to 145°. The spontaneous imbibition tests showed that the oil recovery of 0.1 wt% active nanofluids was 20.5% and 8.5% higher than that of 3 wt% NaCl solution and 0.1 wt% BSSB-12 solution. Finally, the effects of nanofluids on dynamic contact angle, dynamic interfacial tension and moduli were studied from the adsorption behavior of nanofluids at solid–liquid and liquid–liquid interface. The oil detaching and transporting are completed by synergistic effect of wettability alteration and interfacial tension reduction. The findings of this study can help in better understanding of active nanofluids for EOR in ultra-low permeability reservoirs.

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