Current Perspective on the Study of Liquid-Fluid Interfaces: From Fundamentals to Innovative Applications

A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Liquid–Fluid Coatings, Surfaces and Interfaces".

Deadline for manuscript submissions: closed (20 May 2022) | Viewed by 28397

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Special Issue Editor

Department of Physical Chemistry, Complutense University of Madrid, Spain
Interests: polyelectrolyte, colloids, emulsions, foams, interfaces, layer-by-layer, adsorption, interfacial rheology
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Special Issue Information

Dear Colleagues,

Liquid–fluid interfaces are ubiquitous, playing a central role in different aspects of industry, nature or life. This makes it necessary to deepen our understanding of the physicochemical behavior governing such interfaces. However, this is not always easy and must be analyzed from the impact of molecular and supramolecular species on the flows occurring within the interfacial region or on the thickness of the interface. Furthermore, the broken symmetry associated with the formation of a liquid–fluid interface can be used a platform for the assembly of innovative materials with reduced dimensionality, which can have an impact in different technological and industrial field, including food science, cosmetics, biology, oil recovery, electronic, drug delivery, detergency, and tissue engineering. Therefore, the study of the most fundamental aspect of liquid–fluid interfaces, and the control of their equilibrium properties and the dynamics processes occurring within the interface, are paramount to exploit the entire potential of interfacial systems in science and technology. This requires a multidisciplinary approach involving researchers from different areas: chemistry, physics, pharmacy, biophysics, medicine, engineering or materials science.

For the above reasons, this Special Issue is intended to provide a general approach to fundamental and applied aspects related to the study of systems involving liquid–fluid interfaces, with the aim of providing a comprehensive perspective on the current state of the research field. It is expected that this can help to close the gap between the most fundamental knowledge on fluid interface and the development of new applications based on it.

The Special Issue is open to reviews and research articles within, but not limited to, the following topics:

  • Complex fluids;
  • Langmuir/Gibbs films;
  • Equilibrium properties of liquid–fluid interfaces;
  • Confinement at liquid–fluid interfaces;
  • Interfacial rheology;
  • Interfacial flows;
  • Biomimetic layers;
  • Lung surfactant;
  • Particle-laden interfaces;
  • Polymer, surfactant, particles, and their mixtures at liquid–fluid interfaces;
  • Evaporation, spreading, and patterning (coffee-ring formation);
  • Emulsions and foams;
  • Liquid–fluid interfaces as a platform for the fabrication of nanomaterials;
  • Surface-sensitive techniques.

Dr. Eduardo Guzmán
Guest Editor

Manuscript Submission Information

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Keywords

  • interfaces
  • confinement
  • dynamics
  • materials
  • applications

Published Papers (13 papers)

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Editorial

Jump to: Research, Review

3 pages, 200 KiB  
Editorial
Current Perspective on the Study of Liquid–Fluid Interfaces: From Fundamentals to Innovative Applications
by Eduardo Guzmán
Coatings 2022, 12(6), 841; https://doi.org/10.3390/coatings12060841 - 16 Jun 2022
Cited by 3 | Viewed by 1116
Abstract
Liquid–fluid interfaces are ubiquitous systems, having a paramount importance for daily life as well as for academia, providing the basis for the study of different aspects of interest for medicine, biology, and physics [...] Full article

Research

Jump to: Editorial, Review

15 pages, 1580 KiB  
Article
Entropy Optimization on Axisymmetric Darcy–Forchheimer Powell–Eyring Nanofluid over a Horizontally Stretching Cylinder with Viscous Dissipation Effect
by Muhammad Rooman, Muhammad Asif Jan, Zahir Shah, Narcisa Vrinceanu, Santiago Ferrándiz Bou, Shahid Iqbal and Wejdan Deebani
Coatings 2022, 12(6), 749; https://doi.org/10.3390/coatings12060749 - 30 May 2022
Cited by 13 | Viewed by 1513
Abstract
The effect of entropy optimization on an axisymmetric Darcy–Forchheimer Powell–Eyring nanofluid flow caused by a horizontally permeable stretching cylinder, as well as non-linear thermal radiation, was investigated in this research work. The leading equations of the current problem were changed into ODEs by [...] Read more.
The effect of entropy optimization on an axisymmetric Darcy–Forchheimer Powell–Eyring nanofluid flow caused by a horizontally permeable stretching cylinder, as well as non-linear thermal radiation, was investigated in this research work. The leading equations of the current problem were changed into ODEs by exhausting appropriate transformations. To deduce the reduced system, the numerical method bvp4c was used. The outcome of non-dimensional relevant factors on velocity, entropy, concentration, temperature, Bejan number, drag force, and Nusselt number is discussed and demonstrated using graphs and tables. It is perceived that, with a higher value of volume fraction parameter, the skin friction falls down. Likewise, it is found that the Nusselt number drops with enhancing the value of the volume fraction. Moreover, the result reveals that the entropy generation increases as the volume fraction, curvature parameter, and Brinkman number increase. Full article
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21 pages, 16074 KiB  
Article
Mathematical Modelling of Ree-Eyring Nanofluid Using Koo-Kleinstreuer and Cattaneo-Christov Models on Chemically Reactive AA7072-AA7075 Alloys over a Magnetic Dipole Stretching Surface
by Zahir Shah, Narcisa Vrinceanu, Muhammad Rooman, Wejdan Deebani and Meshal Shutaywi
Coatings 2022, 12(3), 391; https://doi.org/10.3390/coatings12030391 - 15 Mar 2022
Cited by 18 | Viewed by 2198
Abstract
In the current study, since nanofluids have a high thermal resistance, and because non-Newtonian (Ree-Eyring) fluid movement on a stretching sheet by means of suspended nanoparticles AA7072-AA7075 is used, the proposed mathematical model takes into account the [...] Read more.
In the current study, since nanofluids have a high thermal resistance, and because non-Newtonian (Ree-Eyring) fluid movement on a stretching sheet by means of suspended nanoparticles AA7072-AA7075 is used, the proposed mathematical model takes into account the influence of magnetic dipoles and the Koo-Kleinstreuer model. The Cattaneo-Christov model is used to calculate heat transfer in a two-dimensional flow of Ree-Eyring nanofluid across a stretching sheet, and viscous dissipation is taken into account. The base liquid water with suspended nanoparticles AA7072-AA7075 is considered in this study. The PDEs are converted into ODEs by exhausting similarity transformations. The numerical solution of the altered equations is then performed utilising the HAM. To examine the performance of velocity, temperature profiles, concentration profiles, skin friction, the Nusselt number, and the Sherwood number, a graphical analysis is carried out for various parameters. The new model’s key conclusions are that the AA7075 alloy outperforms the AA7072 alloy in terms of thermal performance as the volume fraction and ferro-magnetic interaction constraint rise. Additionally, the rate of heat transmission and the skin friction coefficient improve as the volume fraction rises. Full article
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11 pages, 1382 KiB  
Article
Microscopy-Assisted Digital Image Analysis with Trainable Weka Segmentation (TWS) for Emulsion Droplet Size Determination
by Pelin Salum, Onur Güven, Levent Yurdaer Aydemir and Zafer Erbay
Coatings 2022, 12(3), 364; https://doi.org/10.3390/coatings12030364 - 09 Mar 2022
Cited by 5 | Viewed by 2804
Abstract
The size distribution of droplets in emulsions is very important for adjusting the effects of many indices on their quality. In addition to other methods for the determination of the size distribution of droplets, the usage of machine learning during microscopic analyses can [...] Read more.
The size distribution of droplets in emulsions is very important for adjusting the effects of many indices on their quality. In addition to other methods for the determination of the size distribution of droplets, the usage of machine learning during microscopic analyses can enhance the reliability of the measurements and decrease the measurement cost at the same time. Considering its role in emulsion characteristics, in this study, the droplet size distributions of emulsions prepared with different oil/water phase ratios and homogenization times were measured with both a microscopy-assisted digital image analysis technique and a well-known laser diffraction method. The relationships between the droplet size and the physical properties of emulsions (turbidity and viscosity) were also investigated. The results showed that microscopic measurements yielded slightly higher values for the D(90), D[3,2], and D[4,3] of emulsions compared to the laser diffraction method for all oil/water phase ratios. When using this method, the droplet size had a meaningful correlation with the turbidity and viscosity values of emulsions at different oil/water phase ratios. From this point of view, the usage of the optical microscopy method with machine learning can be useful for the determination of the size distribution in emulsions. Full article
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12 pages, 10374 KiB  
Article
Patterning Configuration of Surface Hydrophilicity by Graphene Nanosheet towards the Inhibition of Ice Nucleation and Growth
by Biao Jiang, Yizhou Shen, Jie Tao, Yangjiangshan Xu, Haifeng Chen, Senyun Liu, Weilan Liu and Xinyu Xie
Coatings 2022, 12(1), 52; https://doi.org/10.3390/coatings12010052 - 02 Jan 2022
Cited by 1 | Viewed by 1991
Abstract
Freezing of liquid water occurs in many natural phenomena and affects countless human activities. The freezing process mainly involves ice nucleation and continuous growth, which are determined by the energy and structure fluctuation in supercooled water. Herein, considering the surface hydrophilicity and crystal [...] Read more.
Freezing of liquid water occurs in many natural phenomena and affects countless human activities. The freezing process mainly involves ice nucleation and continuous growth, which are determined by the energy and structure fluctuation in supercooled water. Herein, considering the surface hydrophilicity and crystal structure differences between metal and graphene, we proposed a kind of surface configuration design, which was realized by graphene nanosheets being alternately anchored on a metal substrate. Ice nucleation and growth were investigated by molecular dynamics simulations. The surface configuration could induce ice nucleation to occur preferentially on the metal substrate where the surface hydrophilicity was higher than the lateral graphene nanosheet. However, ice nucleation could be delayed to a certain extent under the hindering effect of the interfacial water layer formed by the high surface hydrophilicity of the metal substrate. Furthermore, the graphene nanosheets restricted lateral expansion of the ice nucleus at the clearance, leading to the formation of a curved surface of the ice nucleus as it grew. As a result, ice growth was suppressed effectively due to the Gibbs–Thomson effect, and the growth rate decreased by 71.08% compared to the pure metal surface. Meanwhile, boundary misorientation between ice crystals was an important issue, which also prejudiced the growth of the ice crystal. The present results reveal the microscopic details of ice nucleation and growth inhibition of the special surface configuration and provide guidelines for the rational design of an anti-icing surface. Full article
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23 pages, 10177 KiB  
Article
Study of 3-D Prandtl Nanofluid Flow over a Convectively Heated Sheet: A Stochastic Intelligent Technique
by Muhammad Shoaib, Ghania Zubair, Muhammad Asif Zahoor Raja, Kottakkaran Sooppy Nisar, Abdel-Haleem Abdel-Aty and I. S. Yahia
Coatings 2022, 12(1), 24; https://doi.org/10.3390/coatings12010024 - 28 Dec 2021
Cited by 9 | Viewed by 1342
Abstract
In this article, we examine the three-dimensional Prandtl nanofluid flow model (TD-PNFM) by utilizing the technique of Levenberg Marquardt with backpropagated artificial neural network (TLM-BANN). The flow is generated by stretched sheet. The electro conductive Prandtl nanofluid is taken through magnetic field. The [...] Read more.
In this article, we examine the three-dimensional Prandtl nanofluid flow model (TD-PNFM) by utilizing the technique of Levenberg Marquardt with backpropagated artificial neural network (TLM-BANN). The flow is generated by stretched sheet. The electro conductive Prandtl nanofluid is taken through magnetic field. The PDEs representing the TD-PNFM are converted to system of ordinary differential equations, then the obtained ODEs are solved through Adam numerical solver to compute the reference dataset with the variations of Prandtl fluid number, flexible number, ratio parameter, Prandtl number, Biot number and thermophoresis number. The correctness and the validation of the proposed TD-PNFM are examined by training, testing and validation process of TLM-BANN. Regression analysis, error histogram and results of mean square error (MSE), validates the performance analysis of designed TLM-BANN. The performance is ranges 10−10, 10−10, 10−10, 10−11, 10−10 and 10−10 with epochs 204, 192, 143, 20, 183 and 176, as depicted through mean square error. Temperature profile decreases whenever there is an increase in Prandtl fluid number, flexible number, ratio parameter and Prandtl number, but temperature profile shows an increasing behavior with the increase in Biot number and thermophoresis number. The absolute error values by varying the parameters for temperature profile are 10−8 to 10−3, 10−8 to 10−3, 10−7 to 10−3, 10−7 to 10−3, 10−7 to 10−4 and 10−8 to 10−3. Similarly, the increase in Prandtl fluid number, flexible number and ratio parameter leads to a decrease in the concentration profile, whereas the increase in thermophoresis parameter increases the concentration distribution. The absolute error values by varying the parameters for concentration profile are 10−8 to 10−3, 10−7 to 10−3, 10−7 to 10−3 and 10−8 to 10−3. Velocity distribution shows an increasing trend for the upsurge in the values of Prandtl fluid parameter and flexible parameter. Skin friction coefficient declines for the increase in Hartmann number and ratio parameter Nusselt number falls for the rising values of thermophoresis parameter against Nb. Full article
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12 pages, 3737 KiB  
Article
Annealing Effect on the Contact Angle, Surface Energy, Electric Property, and Nanomechanical Characteristics of Co40Fe40W20 Thin Films
by Wen-Jen Liu, Yung-Huang Chang, Chi-Lon Fern, Yuan-Tsung Chen, Tian-Yi Jhou, Po-Chun Chiu, Shih-Hung Lin, Ko-Wei Lin and Te-Ho Wu
Coatings 2021, 11(11), 1268; https://doi.org/10.3390/coatings11111268 - 20 Oct 2021
Cited by 5 | Viewed by 2059
Abstract
This study investigated Co40Fe40W20 single-layer thin films according to their corresponding structure, grain size, contact angle, and surface energy characteristics. Co40Fe40W20 alloy thin films of different thicknesses, ranging from 10 to 50 nm, [...] Read more.
This study investigated Co40Fe40W20 single-layer thin films according to their corresponding structure, grain size, contact angle, and surface energy characteristics. Co40Fe40W20 alloy thin films of different thicknesses, ranging from 10 to 50 nm, were sputtered on Si(100) substrates by DC magnetron sputtering. The thin films were annealed under three conditions: as-deposited, 250 °C, and 350 °C temperatures, respectively. The Scherrer equation was applied to calculate the grain size of Co40Fe40W20 thin films. The results show that the grain size of CoFe(110) increased simultaneously with the increase of post-annealing temperature, suggesting that the crystallinity of Co40Fe40W20 thin films increased with the post-annealing temperature. Moreover, the contact angles of all Co40Fe40W20 thin films were all less than 90°, suggesting that Co40Fe40W20 thin films show changes in the direction of higher hydrophilicity. However, we found that their contact angles decreased as the grain size of CoFe increased. Finally, the Young equation was applied to calculate the surface energy of Co40Fe40W20 thin films. After post-annealing, the surface energy of Co40Fe40W20 thin films increased with the rising post-annealing temperature. This is the highest value of surface energy observed for 350 °C. In addition, the surface energy increased as the contact angle of Co40Fe40W20 thin films decreased. The high surface energy means stronger adhesion, allowing the formation of multilayer thin films with magnetic tunneling junctions (MTJs). The sheet resistance of the as-deposited and thinner CoFeW films is larger than annealed and thicker CoFeW films. When the thickness is from 10 nm to 50 nm, the hardness and Young’s modulus of the CoFeW film also show a saturation trend. Full article
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13 pages, 4113 KiB  
Article
Evaluation of the Durability of Slippery, Liquid-Infused Porous Surfaces in Different Aggressive Environments: Influence of the Chemical-Physical Properties of Lubricants
by Federico Veronesi, Guia Guarini, Alessandro Corozzi and Mariarosa Raimondo
Coatings 2021, 11(10), 1170; https://doi.org/10.3390/coatings11101170 - 27 Sep 2021
Cited by 8 | Viewed by 2307
Abstract
Liquid-repellent surfaces have been extensively investigated due to their potential application in several fields. Superhydrophobic surfaces achieve outstanding water repellence, however their limited durability in severe operational conditions hinders their large-scale application. The Slippery, Liquid-Infused Porous Surface (SLIPS) approach solves many of the [...] Read more.
Liquid-repellent surfaces have been extensively investigated due to their potential application in several fields. Superhydrophobic surfaces achieve outstanding water repellence, however their limited durability in severe operational conditions hinders their large-scale application. The Slippery, Liquid-Infused Porous Surface (SLIPS) approach solves many of the durability problems shown by superhydrophobic surfaces due to the presence of an infused liquid layer. Moreover, SLIPS show enhanced repellence towards low surface tension liquids that superhydrophobic surfaces cannot repel. In this perspective, SLIPS assume significant potential for application in harsh environments; however, a systematic evaluation of their durability in different conditions is still lacking in the literature. In this work, we report the fabrication of SLIPS based on a ceramic porous layer infused with different lubricants, namely perfluoropolyethers with variable viscosity and n-hexadecane; we investigate the durability of these surfaces by monitoring the evolution of their wetting behavior after exposure to severe environmental conditions like UV irradiation, chemically aggressive solutions (acidic, alkaline, and saline), and abrasion. Chemical composition and viscosity of the infused liquids prove decisive in determining SLIPS durability; especially highly viscous infused liquids deliver enhanced resistance to abrasion stress and chemical attack, making them candidates for applicable, long-lasting liquid-repellent surfaces. Full article
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Graphical abstract

19 pages, 1280 KiB  
Article
Nanomechanical Concepts in Magnetically Guided Systems to Investigate the Magnetic Dipole Effect on Ferromagnetic Flow Past a Vertical Cone Surface
by Auwalu Hamisu Usman, Zahir Shah, Poom Kumam, Waris Khan and Usa Wannasingha Humphries
Coatings 2021, 11(9), 1129; https://doi.org/10.3390/coatings11091129 - 16 Sep 2021
Cited by 9 | Viewed by 2119
Abstract
Because of the floating magnetic nanomaterial, ferrofluids have magneto-viscous properties, enabling controllable temperature changes as well as nano-structured fluid characteristics. The study’s purpose is to evolve and solve a theoretical model of bioconvection nanofluid flow with a magnetic dipole effect in the presence [...] Read more.
Because of the floating magnetic nanomaterial, ferrofluids have magneto-viscous properties, enabling controllable temperature changes as well as nano-structured fluid characteristics. The study’s purpose is to evolve and solve a theoretical model of bioconvection nanofluid flow with a magnetic dipole effect in the presence of Curie temperature and using the Forchheimer-extended Darcy law subjected to a vertical cone surface. The model also includes the nonlinear thermal radiation, heat suction/injection, viscous dissipation, and chemical reaction effects. The developed model problem is transformed into nonlinear ordinary differentials, which have been solved using the homotopy analysis technique. In this problem, the behavior of function profiles are graphically depicted and explained for a variety of key parameters. For a given set of parameters, tables representthe expected numerical values and behaviors of physical quantities. The nanofluid velocity decreases as the ferrohydrodynamic, local inertia, and porosity parameters increase and decrease when the bioconvection Rayleigh number increases. Many key parameters improved the thermal boundary layer and temperature. The concentration is low when the chemical reaction parameter and Schmidt number rises. Furthermore, as the bioconvection constant, Peclet and Lewis numbers rise, so does the density of motile microorganisms. Full article
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12 pages, 6085 KiB  
Article
Evaluation of Coating Film Formation Process Using the Fluorescence Method
by Ayako Yano, Kyoichi Hamada and Kenji Amagai
Coatings 2021, 11(9), 1076; https://doi.org/10.3390/coatings11091076 - 06 Sep 2021
Cited by 2 | Viewed by 2134
Abstract
In this paper, we invented a novel observation method of the coating film formation process using the fluorescence method. With this method, the temporal change in the coating film thickness can be evaluated quantitatively. In addition, since the thickness and flow of the [...] Read more.
In this paper, we invented a novel observation method of the coating film formation process using the fluorescence method. With this method, the temporal change in the coating film thickness can be evaluated quantitatively. In addition, since the thickness and flow of the coating film can be measured simultaneously, the detailed coating film formation process was clarified. In the experiment, the adhesion behavior of the spray-paint droplets when applied to a wall was investigated. The characteristics of coating films formed by the spray droplets, particularly the influence of injection pressure on the coating film formation, were determined using the fluorescence method. At the initial stage of the coating process, the coating area increased linearly. When the ratio of the coating area to the measurement range reached about 80%, the rate at which the coating area increased slowed down, and an overlap began. The amount of paint that adhered to the coating film formation could be estimated by calculating the overlap ratio. Moreover, the thickness and smoothness of the coating film were evaluated using the histogram data of the fluorescence intensity. The leveling process was discussed in relation to the standard deviation of the histogram data. In addition, the flow of the paint during the coating film formation was investigated using tracer particles, and the effect of the spray gun injection pressure on the leveling process was investigated. Changes in the film thickness and flow during the coating film formation process could be evaluated through fluorescence observation. Full article
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13 pages, 7074 KiB  
Article
Numerical Investigation on the Evaporation Performance of Desulfurization Wastewater in a Spray Drying Tower without Deflectors
by Debo Li, Ning Zhao, Yongxin Feng and Zhiwen Xie
Coatings 2021, 11(9), 1022; https://doi.org/10.3390/coatings11091022 - 26 Aug 2021
Cited by 5 | Viewed by 1560
Abstract
The desulfurization wastewater evaporation technology with flue gas has been widely applied to dispose of desulfurization wastewater. This paper investigates the effect of flue gas flow rate and temperature, wastewater flow rate and initial temperature, and droplet size on the evaporation performance of [...] Read more.
The desulfurization wastewater evaporation technology with flue gas has been widely applied to dispose of desulfurization wastewater. This paper investigates the effect of flue gas flow rate and temperature, wastewater flow rate and initial temperature, and droplet size on the evaporation performance of the desulfurization wastewater in a spray drying tower without deflectors. The results show that the flue gas flow rate and temperature affect the evaporation performance of desulfurization wastewater. The larger flow rate and higher temperature of flue gas correspond to the faster evaporation speed and the shorter complete evaporation distance of the wastewater droplet. Decreasing the flow rate and increasing the initial temperature of the desulfurization wastewater is advantageous to enhance the evaporation speed and shorten the complete evaporation distance of the wastewater droplet. Reducing the droplet size is beneficial to improve the evaporation performance of the desulfurization wastewater. The orthogonal test results show that the factors affecting droplet evaporation performance are ranked as follows: flue gas flow rate > wastewater flow rate > flue gas temperature > wastewater initial temperature > droplet size. Considering the evaporation ratio and the complete evaporation distance, the optimal setting is 14.470 kg/s for flue gas flow rate, 385 °C for flue gas temperature, 0.582 kg/s for wastewater flow rate, 25 °C for wastewater initial temperature, and 60 μm for droplet size. These studied results can provide valuable information to improve the operational performance of the desulfurization wastewater evaporation technology with flue gas. Full article
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17 pages, 665 KiB  
Article
On the Analysis of the Non-Newtonian Fluid Flow Past a Stretching/Shrinking Permeable Surface with Heat and Mass Transfer
by Shahid Khan, Mahmoud M. Selim, Aziz Khan, Asad Ullah, Thabet Abdeljawad, Ikramullah, Muhammad Ayaz and Wali Khan Mashwani
Coatings 2021, 11(5), 566; https://doi.org/10.3390/coatings11050566 - 12 May 2021
Cited by 26 | Viewed by 2348
Abstract
The 3D Carreau fluid flow through a porous and stretching (shrinking) sheet is examined analytically by taking into account the effects of mass transfer, thermal radiation, and Hall current. The model equations, which consist of coupled partial differential equations (PDEs), are simplified to [...] Read more.
The 3D Carreau fluid flow through a porous and stretching (shrinking) sheet is examined analytically by taking into account the effects of mass transfer, thermal radiation, and Hall current. The model equations, which consist of coupled partial differential equations (PDEs), are simplified to ordinary differential equations (ODEs) through appropriate similarity relations. The analytical procedure of HAM (homotopy analysis method) is employed to solve the coupled set of ODEs. The functional dependence of the hydromagnetic 3D Carreau fluid flow on the pertinent parameters are displayed through various plots. It is found that the x-component of velocity gradient (f(η)) enhances with the higher values of the Hall and shrinking parameters (m,ϱ), while it reduces with magnetic parameter and Weissenberg number (M,We). The y-component of fluid velocity (g(η)) rises with the augmenting values of m and M, while it drops with the augmenting viscous nature of the Carreau fluid associated with the varying Weissenberg number. The fluid temperature θ(η) enhances with the increasing values of radiation parameter (Rd) and Dufour number (Du), while it drops with the rising Prandtl number (Pr). The concentration field (ϕ(η)) augments with the rising Soret number (Sr) while drops with the augmenting Schmidt number (Sc). The variation of the skin friction coefficients (Cfx and Cfz), Nusselt number (Nux) and Sherwood number (Shx) with changing values of these governing parameters are described through different tables. The present and previous published results agreement validates the applied analytical procedure. Full article
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Review

Jump to: Editorial, Research

34 pages, 3902 KiB  
Review
Fluid Films as Models for Understanding the Impact of Inhaled Particles in Lung Surfactant Layers
by Eduardo Guzmán
Coatings 2022, 12(2), 277; https://doi.org/10.3390/coatings12020277 - 19 Feb 2022
Cited by 7 | Viewed by 3098
Abstract
Pollution is currently a public health problem associated with different cardiovascular and respiratory diseases. These are commonly originated as a result of the pollutant transport to the alveolar cavity after their inhalation. Once pollutants enter the alveolar cavity, they are deposited on the [...] Read more.
Pollution is currently a public health problem associated with different cardiovascular and respiratory diseases. These are commonly originated as a result of the pollutant transport to the alveolar cavity after their inhalation. Once pollutants enter the alveolar cavity, they are deposited on the lung surfactant (LS) film, altering their mechanical performance which increases the respiratory work and can induce a premature alveolar collapse. Furthermore, the interactions of pollutants with LS can induce the formation of an LS corona decorating the pollutant surface, favoring their penetration into the bloodstream and distribution along different organs. Therefore, it is necessary to understand the most fundamental aspects of the interaction of particulate pollutants with LS to mitigate their effects, and design therapeutic strategies. However, the use of animal models is often invasive, and requires a careful examination of different bioethics aspects. This makes it necessary to design in vitro models mimicking some physico-chemical aspects with relevance for LS performance, which can be done by exploiting the tools provided by the science and technology of interfaces to shed light on the most fundamental physico-chemical bases governing the interaction between LS and particulate matter. This review provides an updated perspective of the use of fluid films of LS models for shedding light on the potential impact of particulate matter in the performance of LS film. It should be noted that even though the used model systems cannot account for some physiological aspects, it is expected that the information contained in this review can contribute on the understanding of the potential toxicological effects of air pollution. Full article
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