iMechanica - wetting
https://imechanica.org/taxonomy/term/4374
enDroplets on lubricated surfaces: The slow dynamics of skirt formation
https://imechanica.org/node/25997
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/4374">wetting</a></div><div class="field-item odd"><a href="/taxonomy/term/4076">Droplet</a></div><div class="field-item even"><a href="/taxonomy/term/13458">vdW</a></div><div class="field-item odd"><a href="/taxonomy/term/6386">lubrication</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Dear iMechanicians,</p>
<p>I would like to share our recent work published in Phys. Rev. Fluids on the statics and dynamics of droplets on lubricated surfaces: </p>
<p><a href="https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.7.054003"><strong>Droplets on lubricated surfaces: The slow dynamics of skirt formation</strong></a></p>
<p>Zhaohe Dai and Dominic Vella</p>
<p>A key question in the interaction of droplets with lubricated and liquid-infused surfaces is what determines the apparent contact angle of droplets. Previous work has determined this using measured values of the geometry of the “skirt”—the meniscus-like deformation that forms around the base of the deposited droplet. Here, we consider theoretically the equilibrium of a droplet on a smooth, impermeable lubricant-coated surface, and we argue that the small effect of gravity within the skirt and the size of the substrate are important for determining the final equilibrium. However, we also show that the evolution of the skirt toward this ultimate equilibrium is extremely slow (on the order of days for typical experimental parameter values). We therefore suggest that previous experiments on smooth lubricated surfaces may have observed only slowly-evolving transients, rather than “true” equilibria, potentially explaining why a wide range of skirt sizes have been reported.</p>
<p>The data for this work is also available from <a href="https://ora.ox.ac.uk/objects/uuid:a68a9057-39b4-4b38-8ea4-20bd5ee02c3c">ORA</a>. <span>This project has received funding from the European Union’s Horizon 2020 research and </span><span>innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 886028</span></p>
<p>Thanks for your attention. </p>
<p>Zhaohe</p>
</div></div></div>Sat, 28 May 2022 05:36:23 +0000Zhaohe Dai25997 at https://imechanica.orghttps://imechanica.org/node/25997#commentshttps://imechanica.org/crss/node/25997Contact Angle Hysteresis
https://imechanica.org/node/23696
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/12660">Contact angle hysteresis</a></div><div class="field-item odd"><a href="/taxonomy/term/4374">wetting</a></div><div class="field-item even"><a href="/taxonomy/term/217">surface energy</a></div><div class="field-item odd"><a href="/taxonomy/term/6577">capillary</a></div><div class="field-item even"><a href="/taxonomy/term/12661">liquid bridge</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span><strong><span><span><a href="https://www.sciencedirect.com/science/article/pii/S092777571830606X">Dynamic Contact Angle Hysteresis</a></span></span></strong></span></p>
<p><span><a class="doi" title="Persistent link using digital object identifier" href="https://doi.org/10.1016/j.colsurfa.2018.07.004" target="_blank" rel="noopener noreferrer">https://doi.org/10.1016/j.colsurfa.2018.07.004</a><strong><span><span><br /></span></span></strong></span></p>
<p><span><span><a href="https://www.researchgate.net/publication/321794549_Dynamic_contact_angle_hysteresis_in_liquid_bridges">Contact angle hysteresis</a>, and the differences between advancing and receding contact angles under dynamic conditions were studied by examining liquid bridges between moving plates. The observed phenomena are of relevance for a broad range of applications involving capillary forces and wetted particulate matter.</span><br /></span></p>
<p><span><span>Notably, using difference liquides it was found that power law relationships exist between the dynanic contact angle and the capillary numbers for the given conditions.</span></span></p>
<p><span><span><img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571830606X-ga1.jpg" /></span></span></p>
<p> <a href="https://arxiv.org/pdf/1712.04703">Full article </a> <span><strong>Abstract</strong></span> This work presents an experimental study of dynamic contact angle hysteresis using liquid bridges under cyclic compression and stretching between two identical plates. Under various loading rates, contact angle hystereses for three different liquids were measured by examination of advancing and receding liquid bridges, and the capillary forces were recorded. It is found that for a given liquid, the hysteretic behaviour of the contact angle is more pronounced at higher loading rates. By unifying the behaviour of the three liquids, power-law correlations were proposed to describe the relationship between the dynamic contact angle and the capillary number for advancing and receding cases. It is found that the exponents of obtained power-law correlations differ from those derived through earlier methods (e.g., capillary rise), due to the different kinematics of the contact line. The various hysteretic loops of capillary force in liquid bridges under varied cyclic loading rates were also observed, which can be captured quantitatively by the prediction of our developed model incorporating the dynamic contact angle hysteresis. These results illustrate the importance of varying contact line geometries during dynamic wetting and dewetting processes, and warrant an improved modelling approach for higher level phenomena involving these processes, e.g., multiphase flow in porous media and liquid transfer between surfaces with moving contact lines.
</p><p> </p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/contact%20angle%20hysteresis.pdf" type="application/pdf; length=1692486">contact angle hysteresis.pdf</a></span></td><td>1.61 MB</td> </tr>
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</div></div></div>Mon, 21 Oct 2019 08:52:11 +0000Dr. Hanaor - Department of Ceramic Materials - TU Berlin23696 at https://imechanica.orghttps://imechanica.org/node/23696#commentshttps://imechanica.org/crss/node/23696PostDoctoral Position - Universities Paris 7 & Paris 13 , Paris, France
https://imechanica.org/node/18046
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/73">job</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/10367">Mechanical and numerical modeling</a></div><div class="field-item odd"><a href="/taxonomy/term/3950">soft materials</a></div><div class="field-item even"><a href="/taxonomy/term/4374">wetting</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>no longer available.</p>
<p>--</p>
<p>A 15 months post Doctoral position is avalaible on mechanical and numerical modeling fields. This is a join project between Univ. Paris 7 & Paris 13.</p>
<p>The present postdoc subject is focussed on situations in which a wetting or dewetting front is interacting with a soft, more or less deformable material.</p>
<p>More details in the enclosed pdf description file.</p>
<p>Contacts : <br />R. Laurent Limat, MSC, UMR 7057 CNRS, University Paris 7 (ldlimat(at)gmail.com)<br />Prof. Ioan R. Ionescu, LSPM, University Paris 13 (ioan.r.ionescu(at)gmail.com)</p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/POSTdocElastowet.pdf" type="application/pdf; length=228940">POSTdocElastowet.pdf</a></span></td><td>223.57 KB</td> </tr>
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</div></div></div>Wed, 11 Mar 2015 16:20:59 +0000yann.charles18046 at https://imechanica.orghttps://imechanica.org/node/18046#commentshttps://imechanica.org/crss/node/18046Spatial Control in the Heterogeneous Nucleation of Water
https://imechanica.org/node/6799
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/4356">nucleation</a></div><div class="field-item odd"><a href="/taxonomy/term/4357">condensation</a></div><div class="field-item even"><a href="/taxonomy/term/4360">superhydrophobic</a></div><div class="field-item odd"><a href="/taxonomy/term/4361">superhydrophilic</a></div><div class="field-item even"><a href="/taxonomy/term/4374">wetting</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">
The attache<img src="/files/images/water_nucleation_0.jpg" alt=" " width="237" height="109" align="left" />d paper was recently published<br />
in Applied Physics Letters. We show for the first time that Nucleation and<br />
Condensation of Water can be spatially controlled. Such control of nucleation<br />
phenomena and the fundamental findings discussed in the paper have implications<br />
for the Energy and Water industry. <span>The paper can be found at <a href="http://link.aip.org/link/?APL/95/094101/1">http://link.aip.org/link/?APL/95/094101/1</a></span>
</p>
</div></div></div>Mon, 21 Sep 2009 03:10:37 +0000Kripa Varanasi6799 at https://imechanica.orghttps://imechanica.org/node/6799#commentshttps://imechanica.org/crss/node/6799Spatial Control in the Heterogeneous Nucleation of Water
https://imechanica.org/node/6788
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">
<span>The attached paper was recently<br />
published in Applied Physics Letters. We show for the first time that<br />
Nucleation and Condensation of Water can be spatially controlled. Such control<br />
of nucleation phenomena and the fundamental findings discussed in the paper have<br />
implications for the Energy and Water industry.</span>
</p>
<p><span>The paper can be found at<br /><a href="http://link.aip.org/link/?APL/95/094101/1">http://link.aip.org/link/?APL/95/094101/1</a></span></p>
</div></div></div><div class="field field-name-taxonomyextra field-type-taxonomy-term-reference field-label-above"><div class="field-label">Taxonomy upgrade extras: </div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div><div class="field-item odd"><a href="/taxonomy/term/4356">nucleation</a></div><div class="field-item even"><a href="/taxonomy/term/4357">condensation</a></div><div class="field-item odd"><a href="/taxonomy/term/4360">superhydrophobic</a></div><div class="field-item even"><a href="/taxonomy/term/4361">superhydrophilic</a></div><div class="field-item odd"><a href="/taxonomy/term/4374">wetting</a></div></div></div>Thu, 17 Sep 2009 17:44:34 +0000Kripa Varanasi6788 at https://imechanica.orghttps://imechanica.org/node/6788#commentshttps://imechanica.org/crss/node/6788Error | iMechanica