To predict the properties of superamphiphobic layers we analyzed wetting a square and hexagonal array vertical pillars composed spheres (radius R) partially sintered together. Apparent contact angles above 150° are obtained by pinning non-polar liquid surface at underside top sphere resulting in Fakir or Cassie state. Analytical equations derived for impalement pressure limiting case A0 ≫ R2, where is area regular unit cell containing single pillar. The close investigated numerically. By...

The apparent contact angle and hysteresis of a droplet on liquid infused surfaces have strong dependence the relative size between its surrounding wetting ridge.

Drops on cylindrical fibers are a familiar sight, for instance in the form of dew drops spider webs. They can exist two competing morphologies, cylindrically symmetric barrel state completely engulfing fiber and an asymmetric clamshell state, which drop touches only sideways. Despite their omnipresence practical relevance, e.g. adherence to separation technology filter materials, physical mechanisms governing stability morphologies remained elusive. Using electrowetting-functionalized we...

We present a ternary free-energy lattice Boltzmann model. The distinguishing feature of our model is that we are able to analytically derive and independently vary all fluid-fluid surface tensions the solid contact angles. carry out number benchmark tests: (i) double emulsions liquid lenses validate tensions, (ii) fluids in with square well compare angles against analytical predictions, (iii) phase separation verify multicomponent fluid dynamics accurately captured. Additionally also...

A rigorous free energy model for ternary fluid flows with density ratio up to of order $O(10^3)$ is presented and implemented using the entropic lattice Boltzmann scheme. The thermodynamically consistent allows a broad range surface tension ratios, covering both partial wetting states where Neumann triangles are formed, full complete encapsulation one components observed. We further demonstrate that we can capture bouncing, adhesive insertive regimes binary collisions between immiscible...

In this article we numerically investigate the onset of motion liquid drops in contact with a plane and homogeneous substrate angle hysteresis. The are driven by body force F = ρgV, where ρ is density liquid, g acceleration gravity, V volume drop. We compare two protocols to vary bond number Bo λ(v)/λ(c) changes either drop size λ(v) V(1/3) or capillary length λ(c) (γ/ρg)(1/2) γ interfacial tension, revealing that transition between pinned steady moving states can be continuous...

Pinning and wicking of a liquid meniscus in square array pillars is investigated numerical energy minimizations compared to wetting experiments.

We employ a free-energy lattice-Boltzmann method to study the dynamics of ternary fluid system consisting liquid drop driven by body force across regularly textured substrate, infused lubricating liquid. focus on case partial wetting lubricants and observe rich interplay between contact line pinning viscous dissipation at lubricant ridge, which become dominant large small apparent angles, respectively. Our numerical investigations further demonstrate that relative importance ridge depends...

We report results of extensive experimental and numerical studies on the suspension water drops deposited cylindrical pillars having circular square cross sections different wettabilities. In case pillars, drop contact line is pinned to whole edge contour until collapses due action gravity. contrast, are suspended four corners spilling along vertical walls observed. have also studied ability two geometries sustain found that if we compare with same characteristic size, more efficient in...

Superhydrophobic materials are often inspired by nature, whereas metamaterials engineered to have properties not usually occurring naturally. In both, the key their unique is structure. Here, it shown that a negative Poisson's ratio (auxetic) mechanical metamaterial can transform into superhydrophobic material. When stretched, its surface has counterintuitive property also expands in orthogonal lateral direction. The change solid fraction as strain applied modeled, and decreases space...

We report results of extensive experimental and numerical studies the anisotropy water drops deposited on single rectangular posts mesoscopic size sculpted different materials. Drops volume top face assume an elongated shape along post direction. Systematic investigations show that while angle measured direction parallel to does not change, one across them increases monotonically with drop volume. The difference in these two angles is found be proportional contact line eccentricity even for...

Droplet impact behavior on a solid surface is critical for many industrial applications such as spray coating, food production, printing, and agriculture. For all of these applications, common challenge to modify control the regime contact time droplets. This becomes more non-Newtonian liquids with complex rheology. In this research, we explored dynamics (by adding different concentrations Xanthan into water) superhydrophobic surfaces. Our experimental results show that by increasing...

We report on the production of cluster-assembled nanostructured titanium oxide (ns-TiOx) surfaces with tailored wettability properties. The contact angle ns-TiOx changes in a controllable and reproducible way by changing morphology through roughness and/or annealing films air at different temperatures. With increasing temperature, reversible switching from hydrophobic to hydrophilic behavior can be obtained, due removal organic contaminants increase surface hydroxyl groups, while control...

We report the results of comprehensive experiments and numerical calculations interfacial morphologies water confined to hydrophilic top face rectangular posts width W = 500 μm lengths between L 5W 30W. A continuous evolution shape from a homogeneous liquid filament bulged back is observed during changes in volume. Above certain threshold length L* 16.0W, transition two discontinuous bistability shapes interval reduced volume V/W(3).

In this article we study the static advancing contact angle θ+a of a liquid interface in with microstructured substrate equipped periodic array circular posts height H, diameter W and center to distance D. Assuming homogeneous material θo gravity be negligible, numerically minimize interfacial energy an asymptotically plane aligned row for fixed value apparent θa. A number branches mechanically stable morphologies are observed classified by topology three phase line. Increasing θa small...

In the absence of gravity, wetting droplets on fibers is characterized by competition between an axisymmetric barrel morphology engulfing fiber and a symmetry-broken clamshell with droplet sitting side fiber. generic case nonzero buoyancy cylindrical symmetry broken, yet barrels clamshells can still be distinguished based their different interfacial topologies being multiply simply connected, respectively. Next to contact angle size capillary length appears as third parameter controlling...

Equilibrium shapes of coalesced pendular bridges in a static assembly spherical beads are computed by numerical minimization the interfacial energy. Our present study focuses on generic bead configurations involving three beads, one which is contact to two others while there gap variable size between latter. In agreement with previous experimental studies, we find "trimer" morphologies consisting bridges, and "dimers" bridges. certain range opening observe bistability dimer trimer morphology...

We theoretically investigate the apparent contact angle of drops on liquid infused surfaces as a function relative size wetting ridge and deposited drop. provide an intuitive geometrical interpretation whereby variation in is due to rotation Neumann triangle at lubricant-drop-gas line. also derive linear quadratic corrections power series expansion terms pressure differences between lubricant, drop gas phases. These expressions are much simpler more compact compared those previously derived...

Understanding the flow properties of multicomponent fluid systems is important for many natural phenomena and technological applications. The authors extend a lattice Boltzmann approach to model wetting solid boundaries, critically compare different slip mechanisms. work opens up wide range applications be studied.

The equilibrium shape of a drop in contact with solid surfaces can undergo continuous or discontinuous transitions upon changes either volume surface energies. In many instances, such involve the motion three-phase line and are thus sensitive to angle hysteresis. Using combination electrowetting-based experiments numerical calculations, we demonstrate for generic sphere-plate confinement geometry how hysteresis affects mechanical stability competing axisymmetric nonaxisymmetric conformations...

The motion of drops colliding with a straight chemical step is strongly affected by contact angle hysteresis and interfacial pinning.

The stability of sand castles is determined by the structure wet granulates. Experimental data on size distribution fluid pockets are ambiguous with regard to their origin. We discovered that contact-angle hysteresis plays a fundamental role in equilibrium bridge volumes, and not geometrical disorder as commonly conjectured. This has substantial consequences mechanical properties granular beds, including history-dependent rheology lowered strength. Our findings obtained using model which...

Anisotropic spreading of liquids and elongated droplet shapes are often encountered on surfaces decorated with a periodic micropattern linear surface topographies. Numerical calculations wetting experiments show that the shape evolution droplets slowly growing parallel grooves can be grouped into two distinct morphological regimes. In first regime, liquid spreads only direction to grooves. second three-phase contact line advances also perpendicular grooves, whereas approach scale-invariant...