scholarly journals Contact Line Pinning Is Not Required for Nanobubble Stability on Copolymer Brushes

2018 ◽  
Vol 9 (15) ◽  
pp. 4239-4244 ◽  
Author(s):  
David S. Bull ◽  
Nathaniel Nelson ◽  
Danielle Konetski ◽  
Christopher N. Bowman ◽  
Daniel K. Schwartz ◽  
...  
2015 ◽  
Vol 784 ◽  
pp. 465-486 ◽  
Author(s):  
Leonardo Espín ◽  
Satish Kumar

Wetting of permeable substrates by liquids is an important phenomenon in many natural and industrial processes. Substrate heterogeneities may significantly alter liquid spreading and interface shapes, which in turn may alter liquid imbibition. A new lubrication-theory-based model for droplet spreading on permeable substrates that incorporates surface roughness is developed in this work. The substrate is assumed to be saturated with liquid, and the contact-line region is described by including a precursor film and disjoining pressure. A novel boundary condition for liquid imbibition is applied that eliminates the need for a droplet-thickness-dependent substrate permeability that has been employed in previous models. A nonlinear evolution equation describing droplet height as a function of time and the radial coordinate is derived and then numerically solved to characterize the influence of substrate permeability and roughness on axisymmetric droplet spreading. Because it incorporates surface roughness, the new model is able to describe the contact-line pinning that has been observed in experiments but not captured by previous models.


Langmuir ◽  
2011 ◽  
Vol 27 (11) ◽  
pp. 6890-6896 ◽  
Author(s):  
Siang-Jie Hong ◽  
Feng-Ming Chang ◽  
Tung-He Chou ◽  
Seong Heng Chan ◽  
Yu-Jane Sheng ◽  
...  

2018 ◽  
Vol 122 (30) ◽  
pp. 17184-17189 ◽  
Author(s):  
Hongguang Zhang ◽  
Shan Chen ◽  
Zhenjiang Guo ◽  
Yawei Liu ◽  
Fernando Bresme ◽  
...  

Author(s):  
Partha P. Chakraborty ◽  
Melanie M. Derby

Abstract Altering soil wettability by inclusion of hydrophobicity could be an effective way to restrict evaporation from soil, thereby conserving water resources. In this study, 4-μL sessile water droplets were evaporated from an artificial soil millipore comprised of three glass (i.e. hydrophilic) and Teflon (i.e. hydrophobic) 2.38-mm-diameter beads. The distance between the beads were kept constant (i.e. center-to-center spacing of 3.1 mm). Experiments were conducted in an environmental chamber at an air temperature of 20°C and 30% and 75% relative humidity (RH). Evaporation rates were faster (i.e. ∼19 minutes and ∼49 minutes at 30% and 75% RH) from hydrophilic pores than the Teflon one (i.e. ∼24 minutes and ∼52 minutes at 30% and 75% RH) due in part to greater air-water contact area. Rupture of liquid droplets during evaporation was analyzed and predictions were made on rupture based on contact line pinning and depinning, projected surface area just before rupture, and pressure difference across liquid-vapor interface. It was observed that, in hydrophilic pore, the liquid droplet was pinned on one bead and the contact line on the other beads continuously decreased by deforming the liquid-vapor interface, though all three gas-liquid-solid contact lines decreased at a marginal rate in hydrophobic pore. For hydrophilic and hydrophobic pores, approximately 1.7 mm2 and 1.8–2 mm2 projected area of the droplet was predicted at 30% and 75% RH just before rupture occurs. Associated pressure difference responsible for rupture was estimated based on the deformation of curvature of liquid-vapor interface.


2020 ◽  
Vol 312 ◽  
pp. 127983
Author(s):  
Wei Wang ◽  
Qi Wang ◽  
Kaidi Zhang ◽  
Xubo Wang ◽  
Antoine Riaud ◽  
...  

Author(s):  
Sébastien Neukirch ◽  
Arnaud Antkowiak ◽  
Jean-Jacques Marigo

We study the interaction of a liquid drop with an elastic beam in the case where bending effects dominate. We use a variational approach to derive equilibrium equations for the system in the presence of gravity and in the presence or absence of contact line pinning. We show that the derived equilibrium equations for the beam subsystem reveal the external forces applied on the beam by the liquid and vapour phases. Among these, the force applied at the triple line (the curve where the three phases meet) is found to lie along the liquid–vapour interface.


Langmuir ◽  
2010 ◽  
Vol 26 (2) ◽  
pp. 860-865 ◽  
Author(s):  
Pontus S. H. Forsberg ◽  
Craig Priest ◽  
Martin Brinkmann ◽  
Rossen Sedev ◽  
John Ralston

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