Avalanche of particles in evaporating coffee drops

  title={Avalanche of particles in evaporating coffee drops},
  author={Alvaro Marin and Hanneke Gelderblom and Jacco H. Snoeijer and Detlef Lohse},
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 stain ring. In this Fluid Dynamics Video, measurements using micro Particle Image Velocimetry and Particle Tracking clearly show an avalanche of particles being dragged in the last moments, for vanishing contact angles and droplet height. This explains the… Expand
25 Citations
In-plane particle counting at contact lines of evaporating colloidal drops: effect of the particle electric charge.
In this work, in situ counting of fluorescent particles in the vicinity of the triple line of evaporating sessile drops is performed by using confocal laser scanning microscopy and Binary colloidal mixtures were used to illustrate simultaneously the accumulation of particles with two different charge states at the double line. Expand
Surfactant-driven flow transitions in evaporating droplets.
This work is able to show that different types of surfactants turn the droplet's surface either rigid or elastic, which alters the evaporating fluid flow, either enhancing the classical coffee-stain effect or leading to a total flow inversion. Expand
Interfacial flows in sessile evaporating droplets of mineral water.
It is shown that a small "ionic contamination" can cause a significant effect in the flow pattern inside the droplet, and the magnitude of the interfacial flow is practically the same for mineral waters with low content of minerals as that of ultrapure water. Expand
Oscillation dynamics of colloidal particles caused by surfactant in an evaporating droplet
Surfactant-induced Marangoni flows can alter the typical outward capillary flows in a drying droplet. Previous studies show that intricate time-dependent periodic motions of colloidal particles, suchExpand
Particle Segregation at Contact Lines of Evaporating Colloidal Drops: Influence of the Substrate Wettability and Particle Charge-Mass Ratio.
A singular behavior of charged polystyrene particles in binary mixtures under "salt-free" conditions explained by the "colloidal Brazil nut" effect is observed. Expand
Mathematical modeling of pattern formation caused by drying of colloidal film under a mask
In this model, FlexPDE is utilized to solve an advection-diffusion equation using the finite element method and demonstrates that the colloidal particles accumulate below the holes as the solvent evaporates. Expand
Effect of Hydrothermal Waves on Evaporation Distribution During Drop Evaporation
The objective of this study is to clarify physical mechanisms involved in the evaporation of small (a few microliters) sessile drops. We aim to understand the relation between local thermalExpand
Skin layer stratification in drying droplets of dairy colloids
Abstract The evaporation of a colloidal dispersion is characterized by solute accumulation at the air-liquid interface, leading to the gradual formation of a gelled skin. The development of thisExpand
Transitional bulk-solutal Marangoni instability in sessile drops
Evaporation of sessile droplets is a method to organize suspended particles on solid substrates. Many studies have demonstrated that Marangoni flows caused by surface adsorbed molecules orExpand
Evaporation of a Droplet: From physics to applications
Abstract Evaporation of a drop, though a simple everyday observation, provides a fascinating subject for study. Various issues interact here, such as dynamics of the contact line, evaporation-inducedExpand


American Physical Society : Division of Fluid Dynamics
  • Nature
  • 1948
THE Division of Fluid Dynamics of the American Physical Society, which was established by the Council of the American Physical Society in June 1947, has been organised, and the following have beenExpand