Formation of viscoelastic droplets in a step‐emulsification microdevice

Liu, Xiyang; Jiang, Shanshan; Zhu, Chunying; Ma, Youguang

doi:10.1002/aic.17780

Cited by 13 publications

(3 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25 An increase in relaxation time leads to an increase in polymeric droplet length. Liu et al 35 reported similar results for the formation of viscoelastic droplets in a step-emulsification microdevice. The dependence of droplet length on relaxation time is attributed to the restraining…”

Section: Role Of Elasticity On Polymeric Droplet Generation and Morph...mentioning

confidence: 57%

Role of elasticity on polymeric droplet generation and morphology in microfluidic cross-junctions

Duan,

Yuan,

Hao

et al. 2024

Physics of Fluids

View full text Add to dashboard Cite

Recently, our direct numerical simulations [Duan et al., Phys. Fluids 36, 033112 (2024)] showed that fluid elasticity affects the extension length and pinch-off time of the droplet formation process, thus changing the flow pattern. However, the effect of fluid elasticity on the morphology and properties of polymeric droplets is not yet fully understood. In this work, by analyzing the stretched state of the polymer macromolecule and the velocity distribution of the flow process, we find that the increase in fluid elasticity (characterized by the relaxation time) inhibits the contraction of the dispersed phase during droplet pinching and resists the effect of surface tension after droplet generation, which significantly affects the droplet geometry, volume, and generation frequency. The results demonstrate that the length and volume of polymeric droplets increase with the relaxation time of the polymer fluid, while the generation frequency decreases. Meanwhile, the effects of polymer viscosity and the superficial velocity ratio of the continuous to the dispersed phase on the droplets' morphology are investigated. The semi-empirical models for the length, volume, and generation frequency of polymeric droplets are developed for the first time by considering the elastic interaction. The purpose of our work is to provide a better understanding and experimental guidance for controlling the parameters of polymeric droplets with viscoelasticity of different shapes and sizes.

show abstract

Section: Role Of Elasticity On Polymeric Droplet Generation and Morph...mentioning

confidence: 57%

Role of elasticity on polymeric droplet generation and morphology in microfluidic cross-junctions

Duan,

Yuan,

Hao

et al. 2024

Physics of Fluids

View full text Add to dashboard Cite

show abstract

“…The filling of the bulb head is deeply influenced by the difference in Laplace pressure between the higher-curved interface in the triangular nozzle and the less-curved interface in the reservoir. 22,39 With the volume of bulb head continuously increasing, the pressure in the head decreases because the head interface in the reservoir becomes less curved. Therefore, the upstream higher pressure pushes the fluid of the thread into the bulb head, resulting in the appearance of the droplet neck, 40 when the process enters the pinching stage (t* = 4.045-4.687 in Figure 8).…”

Section: Hydrodynamics Underlying Monodispersed Droplet Generationmentioning

confidence: 99%

Robust generation of monodisperse droplets using a microfluidic step emulsification device with triangular nozzle

Liu

et al. 2023

AIChE Journal

View full text Add to dashboard Cite

In this work, the droplet generation process in the microfluidic step emulsification chip with a triangular nozzle (SE‐T) was investigated in the combination of visualization experiment and numerical simulation, through a comparison with a rectangular nozzle (SE‐R). The flow regimes, including dripping, dripping‐jetting transition, and jetting, were observed in the SE‐T, among which the dripping is the preferred flow regime to generate monodispersed droplet with corresponding C.V. (coefficient of variation) of the droplet size smaller than 1.9%. Compared with the SE‐R, the larger space and expanding structure of the triangular nozzle in the SE‐T enhance the wall wetting effects, which induces earlier appearance and accelerates shrinking of the neck. As a result, the SE‐T exhibits more robust droplet performance under the dripping regime, which produces the droplets with nearly unchanged size and higher monodispersity, especially little related to the variations of surfactant concentrations and dispersed phase flow rates.

show abstract

“…However, the impact of fluid properties is not included. He et al and Liu et al studied the droplet formation processes of viscous fluids and viscoelastic fluids in a wedge-shaped step-emulsification microdevice, respectively. The viscosity of the dispersed phase hinders the necking and pinch-off stages, promoting the transition from the dripping to the jetting regime.…”

Section: Introductionmentioning

confidence: 99%

Formation of Droplets of Shear-Thinning Fluids in a Wedge-Shaped Step-Emulsification Microdevice

Wang,

He,

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Formation of viscoelastic droplets in a step‐emulsification microdevice

Cited by 13 publications

References 38 publications

Role of elasticity on polymeric droplet generation and morphology in microfluidic cross-junctions

Role of elasticity on polymeric droplet generation and morphology in microfluidic cross-junctions

Robust generation of monodisperse droplets using a microfluidic step emulsification device with triangular nozzle

Formation of Droplets of Shear-Thinning Fluids in a Wedge-Shaped Step-Emulsification Microdevice

Contact Info

Product

Resources

About