Related papers: Coffee stain effect on a fibre from axisymmetric d…
The drying of a drop containing particles often results in the accumulation of the particles at the contact line. In this work, we investigate the drying of an aqueous colloidal drop surrounded by a hydrogel that is also evaporating. We…
Spilling tea or coffee leads to a tell-tale circular stain after the droplet dries, known as the "coffee ring effect". The evaporation of suspension droplets is a complex physical process, and predicting and controlling the particle deposit…
When a colloidal sessile droplet dries on a substrate, the particles suspended in it usually deposit in a ring-like pattern. This phenomenon is commonly referred to as the "coffee-ring" effect. One paradigm for why this occurs is as a…
The pioneering work of Deegan et al. [Nature 389, (1997)] showed how a drying sessile droplet suspension of particles presents a maximum evaporating flux at its contact line which drags liquid and particles creating the well known coffee…
Evaporating a droplet containing dispersed colloids leaves behind a dried deposit whose shape is determined by capillary flows and the resulting particle transport. The classical coffee-ring effect occurs when an outward radial flow drives…
Building on the recent theoretical work of Wray, Duffy and Wilson [J. Fluid Mech. 884, A45 (2020)] concerning the competitive diffusion-limited evaporation of multiple thin sessile droplets in proximity to each other, we obtain theoretical…
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…
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…
Hypothesis: Contact-line motion upon drying of sessile droplet strongly affects the solute transport and solvent evaporation profile. Hence, it should have a strong impact on the deposit formation and might be responsible for volcano-like,…
Our numerical study aims to investigate particle deposit patterns from the evaporation of a sessile colloidal droplet. An in house finite volume code is developed to simulate the coupled phenomena of flow and heat and mass transfer with…
We study the size and shape of the final deposit obtained when a drop with colloidal particles has dried on a super-hydrophobic surface made of micro-posts. As expected, most of the particles lie inside a circular area, which radius roughly…
We present a framework for calculating the surface density profile of a stain deposited by a drop with a receding contact line. Unlike a pinned drop, a receding drop pushes fluid towards its interior, continuously deposits mass across its…
An evaporating droplet is a dynamic system in which flow is spontaneously generated to minimize the surface energy, dragging particles to the borders and ultimately resulting in the so-called "coffee-stain effect". The situation becomes…
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…
"When the liquid phase of a particle-laden droplet evaporates, a ring of solute is typically formed - what has become known as the "coffee ring effect". A key focus of recent work has been the suppression of the coffee-ring effect to leave…
In order to probe the dynamics of contact-line motion, we study the macroscopic properties of sessile drops deposited on and then aspirated from carefully prepared horizontal surfaces. By measuring the contact angle and drop width…
Liquid droplets usually wet smooth and homogeneous substrates isotropically. Recent research works have revealed that droplets sit, slide and spread anisotropically on uniaxially stretched soft substrates, showing an enhanced wettability…
Evaporating colloidal droplets have long been used as model systems to understand capillarity, interfacial transport, and particle assembly, most prominently through the coffee ring effect. In classical descriptions, suspended particles are…
During drying, particle-laden sessile droplets will leave so-called coffee-stain rings behind. This phenomenon is well-known and well-understood (Deegan et al., Nature 389, 827-829 (1997)). Here we show that when particle-laden droplets…
The evaporation of multi-component sessile droplets is key in many physicochemical applications such as inkjet printing, spray cooling, and micro-fabrication. Past fundamental research has primarily concentrated on single drops, though in…