Deposition of Brownian particles during evaporation of two-dimensional sessile droplets

Petsi, A.J.; Kalarakis, A. N.; Burganos, Vasilis N.

doi:10.1016/j.ces.2010.01.028

Cited by 30 publications

(30 citation statements)

References 37 publications

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“…16 There is a vast literature on droplet evaporation. Previous investigations 17,18,19,20,21,22,23,24,25 have shown that for pinned droplets the inner flow is directed outward for low and intermediate hydrophobicity, whereas inward flow is expected for depinned droplets. 19 For strong hydrophobic substrates, the flow is directed outwards for both pinned and de-pinned droplets, but of lower magnitude compared to that on hydrophilic substrates.…”

mentioning

confidence: 94%

Effect of Accommodation Coefficient, Curvature and Three-Dimensional Flow on the Evaporation Characteristics of Pinned Water Microdroplets

Briones

Ervin

Byrd

et al. 2011

42nd AIAA Thermophysics Conference

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A numerical-experimental investigation of pinned, water microdroplet evaporation on an isothermally heated flat surface was conducted by solving the axisymmetric and threedimensional time-dependent governing equations of continuity, momentum, energy, and species. The explicit volume of fluid (VOF) model with dynamic meshing and variable-time stepping on parallel processors was used to capture the time-dependent liquid-gas interface motion throughout the computational domain. The continuum surface force (CSF), the gravitational body force and Schrage's molecular kinetic-based evaporation model were included in the governing equations. The numerical model included temperature-and species-dependent thermodynamic and transport properties. A neutrally hydrophobic droplet was heated on an isothermal surface. Flow is generated in both liquid and gaseous phases due to the combined effects of surface tension gradients, evaporation, and heat conduction and convection. Throughout evaporation, the droplet exhibited higher temperature and curvature at the contact line and lower temperature and curvature at the droplet apex. These scalar gradients along the liquid-gas interface lead to thermalMarangoni driven re-circulating flow. This re-circulating flow causes the wall heat flux (q wall ) to peak both at the centerline and contact line, while the wall shear stress ( wall ) peaks at the contact line only. With decreasing accommodation coefficient (), the re-circulating flow is weakened. Consequently, q wall is reduced while  wall remains almost unaffected, and the droplet lifetime () is extended. Thermal resistance is controlled by the evaporating liquid-gas interface and the time-averaged overall heat transfer coefficient ( ) decreases with decreasing  The evaporation rate for water is sensitive to small changes in . Both 2 predictions and measurements indicate that the net effect of decreasing curvature ( 0 ) by increasing the droplet size is to increase . There are two reasons for this to happen: 1) larger droplets require more total energy than smaller droplets for full evaporation; 2) larger droplets, which consequently are exposed to lower surface tension forces than smaller droplets, develop weaker thermal-Marangoni flows yielding reduced flow re-circulation, which in turn diminishes q wall and . Moreover, the numerical results under-and overpredict  for smaller and larger droplets, respectively, due to lack of de-pinning mechanism and the uncertainty in . Nonetheless, good qualitative comparisons are observed between simulations and experiments. The larger droplets (i.e., smaller  0 ) exhibit vapor bubble formation in their centerline. The experimental results indicate the three-dimensional flows at late stages of evaporation are coupled with the contact line receding motion. Lastly, the three-dimensional model was validated for early and intermediate stages of evaporation. NomenclatureCa = Capillary number = V 0 / CHF = critical heat flux [W/m 2 ] c p = specific heat capacity at constant pressure [J/...

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mentioning

confidence: 94%

Effect of Accommodation Coefficient, Curvature and Three-Dimensional Flow on the Evaporation Characteristics of Pinned Water Microdroplets

Briones

Ervin

Byrd

et al. 2011

42nd AIAA Thermophysics Conference

View full text Add to dashboard Cite

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“…Recently published models considered the Brownian motion of particles inside the droplets. For instance, in the work of Petsi et al [213], the Brownian motion of the particles is superimposed on the hydrodynamic flow calculated previously [231]. A continuum approach has also been applied in some works [59,208,209].…”

Section: D Models Of Massmentioning

confidence: 99%

Droplet Drying Patterns on Solid Substrates: From Hydrophilic to Superhydrophobic Contact to Levitating Drops

Tarafdar

Tarasevich

Choudhury

et al. 2018

Advances in Condensed Matter Physics

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This review is devoted to the simple process of drying a multicomponent droplet of a complex fluid which may contain salt or other inclusions. These processes provide a fascinating subject for study. The explanation of the rich variety of patterns formed is not only an academic challenge but also a problem of practical importance, as applications are growing in medical diagnosis and improvement of coating/printing technology. The fundamental scientific problem is the study of the mechanism of microand nanoparticle self-organization in open systems. The specific fundamental problems to be solved, related to this system, are the investigation of the mass transfer processes, the formation and evolution of phase fronts, and the identification of mechanisms of pattern formation. The drops of liquid containing dissolved substances and suspended particles are assumed to be drying on a horizontal solid insoluble smooth substrate. The chemical composition and macroscopic properties of the complex fluid, the concentration and nature of the salt, the surface energy of the substrate, and the interaction between the fluid and substrate which determines the wetting all affect the final morphology of the dried film. The range of our study encompasses the fully wetting case with zero contact angle between the fluid and substrate to the case where the drop is levitated in space, so there is no contact with a substrate and angle of contact can be considered as 180 ∘ .

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“…Dee gan et al [39,40], Petsi et al [41,42], and Sefiane [43] experimentally investigated and theoretically explained the development of a flow inside a droplet directed toward the three phase contact line and the influence of this flow on the physical processes occur ring in the droplet.…”

Section: Investigation Of Salt Crystallization On a Film Surface By Tmentioning

confidence: 98%

“…-an invariable position of the three phase contact line with decreasing contact angle; -a shifting three phase contact line at a constant contact angle; and -a constant position of the three phase contact line on the surface during some time at a contact angle decreasing to some limiting value, followed by a dra matic shift of the three phase contact line and the res toration of the initial contact angle (stick-slip evapo ration) [42].…”

Section: Investigation Of Salt Crystallization On a Film Surface By Tmentioning

confidence: 99%

Peculiarities of the surface crystallization of sodium chloride on mucin films

et al. 2012

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It is established that the two dimensional crystallization of sodium chloride on the surface of a biopolymer film (film of a glycoprotein, mucin), which is used as a template, gives rise to the formation of crystals with unusual morphology-in particular, dendrites. This type of crystallization is observed in two cases-namely, when drying a film formed from a salt containing mucin dispersion and when drying a salt solution droplet on the surface of a dry mucin film obtained from a salt free mucin dispersion. Mechanisms leading to unusual salt crystallization are discussed, and the role of specific interactions of sodium chloride with mucin is shown.

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Deposition of Brownian particles during evaporation of two-dimensional sessile droplets

Cited by 30 publications

References 37 publications

Effect of Accommodation Coefficient, Curvature and Three-Dimensional Flow on the Evaporation Characteristics of Pinned Water Microdroplets

Effect of Accommodation Coefficient, Curvature and Three-Dimensional Flow on the Evaporation Characteristics of Pinned Water Microdroplets

Droplet Drying Patterns on Solid Substrates: From Hydrophilic to Superhydrophobic Contact to Levitating Drops

Peculiarities of the surface crystallization of sodium chloride on mucin films

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