Related papers: Surfactant-driven flow transitions in evaporating …
The sedimentation of a surfactant-laden deformable viscous drop acted upon by an electric field is considered theoretically. The convection of surfactants in conjunction with the the combined effect electrohydrodynamic flow and…
The impact of droplets on an inclined falling liquid film is studied experimentally using high-speed imaging. The falling film is created on a flat substrate with controllable thicknesses and flow rates. Droplets with different sizes and…
Viscous hydrodynamic flow in a small, slowly evaporating, sessile hemispherical droplet with a pinned contact line is considered. Analytical solutions are obtained for the Deegan outward flow, which is responsible for the coffee ring…
The so-called coffee stain effect has been intensively studied over the past decades, but most of the studies are focused on sessile droplets. In this paper, we analyse the origin of the difference between the deposition of suspended…
The coffee-ring effect is a universal feature of evaporating sessile droplets with pinned contact line, wherein solutes or particles are advected to the droplet's edge due to evaporation-driven flows. While existing models have successfully…
We study the rheology of a suspension of soft deformable droplets subjected to a pressure-driven flow. Through computer simulations, we measure the apparent viscosity as a function of droplet concentration and pressure gradient, and provide…
We have developed a multi-phase SPH method to simulate arbitrary interfaces containing surface active agents (surfactants) that locally change the properties of the interface, such the surface tension coefficient. Our method incorporates…
The surfactant-driven spreading of droplets is an essential process in many applications ranging from coating flow technology to enhanced oil recovery. Despite the significant advancement in describing spreading processes in…
Evaporating droplets are known to show complex motion that has conventionally been explained by the Marangoni effect (flow induced by the gradient of surface tension). Here, we show that the droplet motion can be induced even in the absence…
This review covers experimental results of evaporative lithography and analyzes existing mathematical models of this method. Evaporating droplets and films are used in different fields, such as cooling of heated surfaces of electronic…
Droplet coalescence is an important process in nature and various technologies (e.g. inkjet printing). Here, we unveil the surfactant mass-transport mechanism and report on several major differences in the coalescence of surfactant-laden…
We study the deformation of a surfactant-covered droplet under shear flow using a phase-field model that explicitly accounts for both the surfactant concentration and its polarization, representing the average molecular orientation. We…
Extremely small amounts of surface-active contaminants are known to drastically modify the hydrodynamic response of the water-air interface. Surfactant concentrations as low as a few thousand molecules per square micron are sufficient to…
Drying complex fluids is a common phenomenon where a liquid phase transforms into a dense or porous solid. This transformation involves several physical processes, such as the diffusion of liquid molecules into the surrounding atmosphere…
The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition and self-assembly. The shape of the final deposit depends on the flows within the droplet…
Formation of coffee stain deposits under evaporation of droplets containing aqueous solution of salts placed on silicone-oil impregnated substrates was observed. The formation of ring-like deposits was registered for various molar…
We present three-dimensional numerical simulations, employing the well-established lattice Boltzmann method, and investigate similarities and differences between surfactants and nanoparticles as additives at a fluid-fluid interface. We…
This paper is devoted to the numerical study of droplet impact on solid substrates in presence of surfactants. We formulate the problem in an energetically variational framework and introduce an incompressible Cahn-Hilliard-Navier-Stokes…
Evaporation of water droplets deposited on metal and polymer substrates was studied. The evaporated droplet demonstrates different behaviors on low-pinning (polymer) and strong-pinning (metallic) surfaces. When deposited on polymer…
The present work investigates numerically the transport of colloidal particles within an evaporating sessile droplet and their deposition on the substrate in unfavourable conditions. The coupled phenomena of fluid flow and heat and mass…