Controlling the drying-induced peeling of colloidal films

Osman, Abdulkadir; Goehring, Lucas; Stitt, E. Hugh; Shokri, Nima

doi:10.1039/d0sm00252f

Cited by 10 publications

(17 citation statements)

References 51 publications

(48 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By comparing the magnitude of the radial and hoop stresses, we correctly predict the emergence of three distinct fracture patterns in dried drops of blood [11]. We also find that the drop profile affects the depth of delamination, which may not reach the drop centre, in line with the experiments of Osman et al [26]. Finally, we show that a sharp decrease in the permeability during drying can result in the formation of depletion fronts that invade the bulk of the drop from the contact line and localise the accumulation of stresses.…”

Section: Introductionsupporting

confidence: 84%

“…Extensive experimental research has been carried out to elucidate the dependence of the fracture pattern on the contact angle [16,17], drying rate [18][19][20], substrate deformability [21], and particle hydrophobicity [22] and concentration [23,24]. However, a detailed theoretical description of stress generation in drying colloidal drops is lacking, with treatments relying on scaling analyses [25] or one-dimensional models that do not capture the evolving and non-uniform geometry of the drop [20,26].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Drying-induced stresses in poroelastic drops on rigid substrates

Hennessy,

Craster,

Matar

2021

Preprint

View full text Add to dashboard Cite

We develop a theory for drying-induced stresses in sessile, poroelastic drops undergoing evaporation on rigid surfaces. Using a lubrication-like approximation, the governing equations of three-dimensional nonlinear poroelasticity are reduced to a single thin-film equation for the drop thickness. We find that the drop experiences compressive elastic stresses but the overall in-plane stress is tensile due to a negative fluid pressure. The mechanical response of the drop is strongly dictated by the initial profile of the solid skeleton, which controls the in-plane deformation, the dominant components of elastic stress, and sets a limit on the depth of delamination that can potentially occur. Our theory suggests that the alignment of desiccation fractures in colloidal drops is selected by the shape of the drop at the point of gelation. We propose that the emergence of three distinct fracture patterns in dried blood drops is a consequence of a non-monotonic drop profile at gelation. Finally, we show that depletion fronts, which separate wet and dry solid, invade the drop from the contact line and localise the generation of mechancial stress during drying.

show abstract

Section: Introductionsupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Drying-induced stresses in poroelastic drops on rigid substrates

Hennessy,

Craster,

Matar

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The apparent liquid contact line recedes on this deposit, which results in the formation of a deposit "foot" growing from the drop edge and towards the drop center 18,19 . Water from the liquid spherical cap flows radially outwards in the porous deposit to compensate for evaporation at the deposit interface 20 . These flows cause poroelastic stresses, which are relieved through the formation of cracks 3,21,22 and by bending of the deposit into a convex structure 12,20,23 (Movie S1).…”

Section: Resultsmentioning

confidence: 99%

“…Water from the liquid spherical cap flows radially outwards in the porous deposit to compensate for evaporation at the deposit interface 20 . These flows cause poroelastic stresses, which are relieved through the formation of cracks 3,21,22 and by bending of the deposit into a convex structure 12,20,23 (Movie S1).…”

Section: Resultsmentioning

confidence: 99%

“…This leads to an avalanchelike crack dynamics that propagates around the circumference of the drop 22 , which is observed in all three crack regimes. To reveal the origin of these dynamics, we visualize the crack formation with high-speed interference microscopy (Phantom Miro 320S, Movie S5), which allows us to determine the air-layer thickness as the deposit delaminates from the substrate and bends upwards 12,20,23,32 , as shown in Figs. 4a-c.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Crack morphologies in drying suspension drops

et al. 2021

View full text Add to dashboard Cite

show abstract

Time-dependent modelling of thin poroelastic films drying on deformable plates

Hennessy

Matar

2023

Eur. J. Appl. Math

View full text Add to dashboard Cite

Understanding the generation of mechanical stress in drying, particle-laden films is important for a wide range of industrial processes. One way to study these stresses is through the cantilever experiment, whereby a thin film is deposited onto the surface of a thin plate that is clamped at one end to a wall. The stresses that are generated in the film during drying are transmitted to the plate and drive bending. Mathematical modelling enables the film stress to be inferred from measurements of the plate deflection. The aim of this paper is to present simplified models of the cantilever experiment that have been derived from the time-dependent equations of continuum mechanics using asymptotic methods. The film is described using nonlinear poroelasticity and the plate using nonlinear elasticity. In contrast to Stoney-like formulae, the simplified models account for films with non-uniform thickness and stress. The film model reduces to a single differential equation that can be solved independently of the plate equations. The plate model reduces to an extended form of the Föppl-von Kármán (FvK) equations that accounts for gradients in the longitudinal traction acting on the plate surface. Consistent boundary conditions for the FvK equations are derived by resolving the Saint-Venant boundary layers at the free edges of the plate. The asymptotically reduced models are in excellent agreement with finite element solutions of the full governing equations. As the Péclet number increases, the time evolution of the plate deflection changes from $t$ to $t^{1/2}$ , in agreement with experiments.

show abstract

Controlling the drying-induced peeling of colloidal films

Abstract: Controlling film peeling by modifying the properties of the evaporating solution and consequently the length of the drying front.

Cited by 10 publications

References 51 publications

Drying-induced stresses in poroelastic drops on rigid substrates

Drying-induced stresses in poroelastic drops on rigid substrates

Crack morphologies in drying suspension drops

Time-dependent modelling of thin poroelastic films drying on deformable plates

Contact Info

Product

Resources

About