Understanding Fundamental Physics of Aqueous Droplet Generation Mechanisms in the Aqueous Environment

Recent advent of Aqueous-Two-Phase-System (ATPS), more biologically friendly compared to conventional oil-water systems, has shown great potential to rapidly generate aqueous droplets without tedious post-processing. However, understanding of underlying physics of droplet formation in ATPS is still in its infancy. In this paper, we investigate hydrodynamic behaviors and mechanisms of all-aqueous droplet formation in two flow-focusing droplet generators. Two incompatible polymers namely polyethylene glycol (PEG) and dextran (DEX) are mixed in water to make ATPS. The influence of inlet pressures and flow-focusing configurations on droplet sizes, and thread breakup length is studied. Flow regime mapping for two different configurations of droplet generators possessing junction angles of 30° and 90° is also obtained. The results show that droplet size is very susceptible to the junction angle while inlet pressures of the PEG and DEX flows readily control four main flow regimes including back flow, dripping, jetting and stratified.

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Microfluidic generation of aqueous two-phase system (ATPS) droplets by controlled pulsating inlet pressures

Lab on a Chip ◽

10.1039/c5lc00217f ◽

2015 ◽

Vol 15 (11) ◽

pp. 2437-2444 ◽

Cited By ~ 57

Author(s):

Byeong-Ui Moon ◽

Steven G. Jones ◽

Dae Kun Hwang ◽

Scott S. H. Tsai

Keyword(s):

Interfacial Tension ◽

Phase System ◽

Flow Focusing ◽

Two Phase ◽

Aqueous Two Phase System ◽

Microfluidic Flow ◽

Aqueous Two Phase Systems ◽

Phase Systems ◽

Ultralow Interfacial Tension

Simple microfluidic flow focusing generation of droplets from ultralow interfacial tension aqueous two phase systems (ATPS).

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Flow regime mapping of aqueous two-phase system droplets in flow-focusing geometries

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2017.07.083 ◽

2017 ◽

Vol 531 ◽

pp. 111-120 ◽

Cited By ~ 19

Author(s):

Mohammad Mastiani ◽

Seokju Seo ◽

Sofia Melgar Jimenez ◽

Nicholas Petrozzi ◽

Myeongsub Mike Kim

Keyword(s):

Flow Regime ◽

Phase System ◽

Flow Focusing ◽

Two Phase ◽

Aqueous Two Phase System

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Numerical Simulation of Liquid-Fueled Detonations by an Eulerian–Lagrangian Model

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns.2011.102 ◽

2012 ◽

Vol 13 (2) ◽

pp. 177-188

Author(s):

Hua Shen ◽

Gang Wang ◽

Kaixin Liu ◽

Deliang Zhang

Keyword(s):

Detonation Velocity ◽

Propagation Velocity ◽

Gaseous Mixture ◽

Numerical Results ◽

Gaseous Detonation ◽

Lagrangian Model ◽

Detonation Waves ◽

Phase System ◽

Two Phase ◽

Droplet Sizes

Abstract In this paper, an Eulerian–Lagrangian two-phase flow model for liquid-fueled detonations is constructed. The gaseous mixture is described by an Eulerian method, and liquid particles in gaseous mixture are traced by a Lagrangian method. An improved space-time conservation element and solution element (CE/SE) scheme is applied to the simulations of detonations in liquid C 10 H 22 -O 2 /air systems. Different fuel droplet sizes and equivalence ratios are considered in the present study. Interestingly, the numerical results show that liquid-fueled detonations have some difference with gaseous detonations. Especially, a deficit in the propagation velocity compared to the gaseous detonation velocity is observed in mixtures with lean fuel and larger droplet sizes, while an increase in the propagation velocity compared to the gaseous detonation velocity is observed in the mixtures with very rich fuel. The surprising phenomenon is analyzed and discussed with the aid of detailed numerical results. In addition, the formation and propagation of two-phase detonation waves are characterized by series of results and the influence of particle radii is also discussed. All numerical results show that the present model can describe the gas-particle two-phase system accurately, and can be applied to numerical simulations of liquid-fueled detonations.

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Water-in-water droplets by passive microfluidic flow focusing

10.32920/ryerson.14639550.v1 ◽

2021 ◽

Author(s):

Byeong-Ui Moon ◽

Niki Abbasi ◽

Steven G. Jones ◽

Dae Kun Hwang ◽

Scott S. H. Tsai

Keyword(s):

Interfacial Tension ◽

Microfluidic System ◽

Column Height ◽

Phase System ◽

Flow Focusing ◽

Two Phase ◽

Passive Flow ◽

Microfluidic Flow ◽

Droplet Production ◽

Order Of Magnitude

We present a simple microfluidic system that generates water-in-water, aqueous two phase system (ATPS) droplets, by passive flow focusing. ATPS droplet formation is achieved by applying weak hydrostatic pressures, with liquid-filled pipette tips as fluid columns at the inlets, to introduce low speed flows to the flow focusing junction. To control the size of the droplets, we systematically vary the interfacial tension and viscosity of the ATPS fluids, and adjust the fluid column height at the fluid inlets. The size of the droplets scales with a power-law of the ratio of viscous stresses in the two ATPS phases. Overall, we find a drop size coefficient of variation (CV; i.e. polydispersity) of about 10 %. We also find that when drops form very close to the flow focusing junction, the drops have CV of less than 1 %. Our droplet generation method is easily scalable: we demonstrate a parallel system that generates droplets simultaneously, and improves the droplet production rate by up to one order-of-magnitude. Finally, we show the potential application of our system for encapsulating cells in water-in-water emulsions, by encapsulating microparticles and cells. To the best of our knowledge, our microfluidic technique is the first that forms low interfacial tension ATPS droplets without applying external perturbations. We anticipate that this simple approach will find utility in drug and cell delivery applications because of the all-biocompatible nature of the water-in-water ATPS environment.

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THE CALCULATION OF THE EFFECTIVE BULK VISCOSITY OF TWO-PHASE SYSTEM CONSISTING OF LIQUID METAL OF THE WELD POOL AND SOLID PARTICLES REFRACTORY POWDER FILLER MATERIAL

10.21506/j.ponte.2018.2.6 ◽

2018 ◽

Vol 74 (2) ◽

Author(s):

Sergey Donskikh ◽

Semin V. N.

Keyword(s):

Liquid Metal ◽

Weld Pool ◽

Bulk Viscosity ◽

Solid Particles ◽

Filler Material ◽

Phase System ◽

Two Phase ◽

Refractory Powder ◽

Powder Filler

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On the Problem of “Two-Phase” Activated Sludge

Water Science & Technology ◽

10.2166/wst.1991.0185 ◽

1991 ◽

Vol 24 (7) ◽

pp. 59-64 ◽

Cited By ~ 1

Author(s):

R. W. Szetela

Keyword(s):

Activated Sludge ◽

Single Phase ◽

Phase System ◽

Two Phase ◽

Wastewater Treatment Process ◽

Sludge Stabilization ◽

Technological Advantage ◽

In Series ◽

State Models ◽

Activated Sludge Systems

Steady-state models are presented to describe the wastewater treatment process in two activated sludge systems. One of these makes use of a single complete-mix reactor; the other one involves two complete-mix reactors arranged in series. The in-series system is equivalent to what is known as the “two-phase” activated sludge, a concept which is now being launched throughout Poland in conjunction with the PROMLECZ technology under implementation. Analysis of the mathematical models has revealed the following: (1) treatment efficiency, excess sludge production, energy consumption, and the degree of sludge stabilization are identical in the two systems; (2) there exists a technological equivalence of “two-phase” sludge with “single-phase” sludge; (3) the “two-phase” system has no technological advantage over the “single-phase” system.

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Interphase distribution of 2-furylethylenes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851642 ◽

1985 ◽

Vol 50 (8) ◽

pp. 1642-1647 ◽

Cited By ~ 2

Author(s):

Štefan Baláž ◽

Anton Kuchár ◽

Ernest Šturdík ◽

Michal Rosenberg ◽

Ladislav Štibrányi ◽

...

Keyword(s):

Partition Coefficient ◽

Partition Coefficients ◽

Transport Rate ◽

Phase System ◽

Two Phase ◽

Interphase Distribution ◽

Distribution Kinetics ◽

System 1 ◽

Kinetics Of

The distribution kinetics of 35 2-furylethylene derivatives in two-phase system 1-octanol-water was investigated. The transport rate parameters in direction water-1-octanol (l1) and backwards (l2) are partition coefficient P = l1/l2 dependent according to equations l1 = logP - log(βP + 1) + const., l2 = -log(βP + 1) + const., const. = -5.600, β = 0.261. Importance of this finding for assesment of distribution of compounds under investigation in biosystems and also the suitability of the presented method for determination of partition coefficients are discussed.

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