Patterned deposition at moving contact lines

Thiele, Uwe

doi:10.1016/j.cis.2013.11.002

Cited by 111 publications

(153 citation statements)

References 190 publications

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“…One of the most important and actively discussed problems is connected to studying structures of colloidal particles, which emerge on the surface of an evaporating sessile droplet and remain on the substrate after drying [6][7][8][9][10][11][12][13]. One of the examples is the effect of evaporative contact line deposition, the so-called coffee-ring effect [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Joint effect of advection, diffusion, and capillary attraction on the spatial structure of particle depositions from evaporating droplets

Kolegov

Barash

2019

Phys. Rev. E

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A simplified model is developed, which allows us to perform computer simulations of the particles transport in an evaporating droplet with a contact line pinned to a hydrophilic substrate. The model accounts for advection in the droplet, diffusion and particle attraction by capillary forces. On the basis of the simulations, we analyze the physical mechanisms of forming of individual chains of particles inside the annular sediment. The parameters chosen correspond to the experiments of Park and Moon [Langmuir 22, 3506 (2006)], where an annular deposition and snakelike chains of colloid particles have been identified. The annular sediment is formed by advection and diffusion transport. We find that the close packing of the particles in the sediment is possible if the evaporation time exceeds the characteristic time of diffusion-based ordering. We show that the chains are formed by the end of the evaporation process due to capillary attraction of particles in the region bounded by a fixing radius, where the local droplet height is comparable to the particle size. At the beginning of the evaporation, the annular deposition is shown to expand faster than the fixing radius moves. However, by the end of the process, the fixing radius rapidly outreaches the expanding inner front of the ring. The snakelike chains are formed at this final stage when the fixing radius moves toward the symmetry axis. arXiv:1903.06003v2 [cond-mat.soft]

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Section: Introductionmentioning

confidence: 99%

Joint effect of advection, diffusion, and capillary attraction on the spatial structure of particle depositions from evaporating droplets

Kolegov

Barash

2019

Phys. Rev. E

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“…7,8 The deposited patterns find applications in sensing, [9][10][11][12][13][14] data storage, 15,16 and photonic band gap materials 17,18 as well as in the fabrication of nanostructured templates 19,20 and of ordered porous materials. [21][22][23][24] The morphology of the deposits is a consequence of the concurrent interplay of several mechanisms, including the flow in the liquid which is generated by the evaporation of the solvent, Marangoni-force and capillarity induced flows, [25][26][27][28][29][30][31] etc. Furthermore, the evaporation of a macroscopic droplet or an unbounded film into an open vapor atmosphere usually yields rather irregular patterns of rugged rings or lines.…”

Section: Introductionmentioning

confidence: 99%

Connecting Monotonic and Oscillatory Motions of the Meniscus of a Volatile Polymer Solution to the Transport of Polymer Coils and Deposit Morphology

et al. 2018

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We study the deposition mechanisms of polymer from a confined meniscus of volatile liquid. In particular, we investigate the physical processes that are responsible for qualitative changes in the pattern deposition of polymer and the underlying interplay of the state of pattern deposition, motion of the meniscus, and the transport of polymer within the meniscus. As a model system we evaporate a solution of poly(methyl methacrylate) (PMMA) in toluene. Different deposition patterns are observed when varying the molecular mass, the initial concentration of the solute, and temperature; these are systematically presented in the form of morphological phase diagrams. The modi of deposition and meniscus motion are correlated. They vary with the ratio between the evaporation-driven convective flux and the diffusive flux of the polymer coils in the solution. In the case of a diffusion-dominated solute transport, the solution monotonically dewets the solid substrate by evaporation, supporting continuous contact line motion and continuous polymer deposition. However, a convection-dominated transport results in an oscillatory ratcheting dewetting-wetting motion of the contact line with more pronounced dewetting phases. The deposition process is then periodic and produces a stripe pattern. The oscillatory motion of the meniscus differs from the well documented stick-slip motion of the meniscus, observed as well, and is attributed to the opposing influences of evaporation and Marangoni stresses, which alternately dominate the deposition process.

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“…Recent studies have focused on transport processes such as the pinning of a wetting line (4), (5), the effect of the solute particle size on the drying process (4), local velocity profiles (6), and evaporation fluxes at the droplet surface (7). A few studies have been centered on the influence of surface properties on drying process (8)- (14), but never concentrated on the role of biomolecular interaction between the solute and the substrate.…”

Section: Introductionmentioning

confidence: 99%

Biomolecular interactions control the shape of stains from drying droplets of complex fluids

Hurth

Bhardwaj

Andalib

et al. 2015

Chemical Engineering Science

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When a sessile droplet of a complex fluid dries, a stain forms on the solid surface. The structure and pattern of the stain can be used to detect the presence of a specific chemical compound in the sessile droplet. In the present work, we investigate what parameters of the stain or its formation can be used to characterize the specific interaction between an aqueous dispersion of beads and its receptor immobilized on the surface. We use the biotin-streptavidin system as an experimental model. Clear dissimilarities were observed in the drying sequences on streptavidin-coated substrates of droplets of aqueous solutions containing biotin-coated or streptavidin-coated beads. Fluorescent beads are used in order to visualize the fluid flow field. We show differences in the distribution of the particles on the surface depending on biomolecular interactions between beads and the solid surface. A mechanistic model is proposed to explain the different patterns obtained during drying. The model describes that the beads are left behind the receding wetting line rather than pulled towards the drop center if the biological binding force is comparable to the surface tension of the receding wetting line. Other forces such as the viscous drag, van der Waals forces, and solid-solid friction forces are found negligible. Simple microfluidics experiments are performed to further illustrate the difference in behavior where is adhesion or friction are present between the bead and substrate due to the biological force. The results of the model are in agreement with the experimental observations which provide insight and design capabilities. A better understanding of the effects of the droplet-surface interaction on the drying mechanism is a crucial first step before the identification of drying patterns can be promisingly applied to areas such as immunology and biomarker detection. Comments NOTICE: this is the author's version of a work that was accepted for publication in Chemical Engineering Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Chemical Engineering Science, [137, (2015)

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Patterned deposition at moving contact lines

Cited by 111 publications

References 190 publications

Joint effect of advection, diffusion, and capillary attraction on the spatial structure of particle depositions from evaporating droplets

Joint effect of advection, diffusion, and capillary attraction on the spatial structure of particle depositions from evaporating droplets

Connecting Monotonic and Oscillatory Motions of the Meniscus of a Volatile Polymer Solution to the Transport of Polymer Coils and Deposit Morphology

Biomolecular interactions control the shape of stains from drying droplets of complex fluids

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