Droplet detachment and pinch-off of bidisperse particulate suspensions

Thiévenaz, Virgile; Rajesh, Sreeram; Sauret, Alban

doi:10.1039/d1sm00593f

Cited by 17 publications

(18 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where A(η) is a prefactor that weakly depends on the viscosity of the solvent, as reported by Thiévenaz et al, 36 γ and ρ are the surface tension and the density of the liquid, respectively. We can fit Eq.…”

Section: Newtonian and Viscoelastic Regimesmentioning

confidence: 94%

Transition to the viscoelastic regime in the thinning of polymer solutions

Rajesh¹,

Thiévenaz²,

Sauret³

2022

Preprint

Self Cite

View full text Add to dashboard Cite

In this study, we investigate the transition between the Newtonian and the viscoelastic regimes during the pinch-off of droplets of dilute polymer solutions and discuss its link to the coil-stretch transition. The detachment of a drop from a nozzle is associated with the formation of a liquid neck that causes the divergence of the local stress in a vanishingly small region. If the liquid is a polymer solution, this increasing stress progressively unwinds the polymer chains, up to a point where the resulting increase in the viscosity slows down drastically the thinning. This threshold to a viscoelastic behavior corresponds to a macroscopic strain rate εc. In the present study, we characterize the variations of εc with respect to the polymer concentration and molar weight, to the solvent viscosity, and to the nozzle size, i.e., the weight of the drop. We provide empirical scaling laws for these variations. We also analyze the thinning dynamics at the transition and show that it follows a self-similar dynamics controlled by the time scale ε−1 c . This characteristic time is different and always shorter than the relaxation time of the polymer.

show abstract

Section: Newtonian and Viscoelastic Regimesmentioning

confidence: 94%

Transition to the viscoelastic regime in the thinning of polymer solutions

Rajesh¹,

Thiévenaz²,

Sauret³

2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Bonnoit et al ( 12 ) have shown that down to a certain neck thickness, a particulate suspension behaves like a homogeneous liquid of matching viscosity. In addition, the thinning dynamics of the suspension can be rescaled onto the dynamics of another viscous liquid ( 17 ). The method consists of stretching the time to pinch-off by a factor

and shifting it by the duration

, thus changing

.…”

Section: Thinning Dynamicsmentioning

confidence: 99%

“…1 , we obtain

, where

is the capillary length (1.5 mm for the silicone oil used here). We estimate the relative viscosity of the suspension

using the Maron–Pierce correlation ( 32 ),

, with

for the suspensions used here ( 17 ). Finally, we obtain the evolution of the critical thickness at the dislocation regime:

…”

Section: Onset Of Heterogeneitymentioning

confidence: 99%

See 1 more Smart Citation

The onset of heterogeneity in the pinch-off of suspension drops

Thiévenaz

Sauret

2022

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Significance The pinch-off of a liquid drop extruded from a nozzle is a canonical situation that involves a series of self-similar regimes ending in a finite-time singularity. This configuration allows for exploring capillary flows over a large range of scales. In the case of suspension drops, the presence of particles breaks the self-similarity by introducing a length scale that can be much larger than the particle diameter. This length scale is a signature of the heterogeneities and delimitates a regime, in which a continuum approach of a suspension can be used from a regime where the discrete nature of the particles is involved.

show abstract

“…16,17 The dynamics of the pinch-off have received great interest over the past decades due to the issues of topology, singularity or self-similarity, 18–22 not only for Newtonian fluids but also for complex fluids. 23–26 Liquid or gas pinch-off is also important in the context of microfluidics as droplets and bubbles are formed by pinch-off in T-junction or flow-focusing devices. 27,28 Although there have been some studies on pinching off in foams, these reports have been limited to cases where the foams themselves pinch off as complex fluids.…”

Section: Introductionmentioning

confidence: 99%