scholarly journals Shrinking, Growing, and Bursting: Microfluidic Equilibrium Control of Water-in-Water Droplets

2021 ◽  
Author(s):  
Byeong-Ui Moon ◽  
Dae Kun Hwang ◽  
Scott S. H. Tsai
Keyword(s):  
Dynamic Equilibrium ◽  
Polymer Concentration ◽  
Dynamic Control ◽  
Microfluidic Channel ◽  
Continuous Phase ◽  
Phase System ◽  
Two Phase ◽  
Equilibrium Control ◽  
Tie Lines

We demonstrate the dynamic control of aqueous two phase system (ATPS) droplets in shrinking, growing, and dissolving conditions. The ATPS droplets are formed passively in a flow focusing microfluidic channel, where the dextran-rich (DEX) and polyethylene glycol-rich (PEG) solutions are introduced as disperse and continuous phases, respectively. To vary the ATPS equilibrium condition, we infuse into a secondary inlet the PEG phase from a different polymer concentration ATPS. We find that the resulting alteration of the continuous PEG phase can cause droplets to shrink or grow by approximately 45 and 30 %, respectively. This volume change is due to water exchange between the disperse DEX and continuous PEG phases, as the system tends towards new equilibria. We also develop a simple model, based on the ATPS binodal curve and tie lines, that predicts the amount of droplet shrinkage or growth, based on the change in the continuous phase PEG concentration. We observe a good agreement between our experimental results and the model. Additionally, we find that, when the continuous phase PEG concentration is reduced such that PEG and DEX phases no longer phase separate, the ATPS droplets are dissolved into the continuous phase. We apply this method to controllably release encapsulated microparticles and cells, and we find that their release occurs within 10 seconds. Our approach uses the dynamic equilibrium of ATPS to control droplet size along the microfluidic channel. By modulating the ATPS equilibrium, we are able to shrink, grow, and dissolve ATPS droplets in situ. We anticipate that this approach may find utility in many biomedical settings, for example, in drug and cell delivery and release applications.

scholarly journals Shrinking, Growing, and Bursting: Microfluidic Equilibrium Control of Water-in-Water Droplets

2021 ◽  
Author(s):  
Byeong-Ui Moon ◽  
Dae Kun Hwang ◽  
Scott S. H. Tsai
Keyword(s):  
Dynamic Equilibrium ◽  
Polymer Concentration ◽  
Dynamic Control ◽  
Microfluidic Channel ◽  
Continuous Phase ◽  
Phase System ◽  
Two Phase ◽  
Equilibrium Control ◽  
Tie Lines

We demonstrate the dynamic control of aqueous two phase system (ATPS) droplets in shrinking, growing, and dissolving conditions. The ATPS droplets are formed passively in a flow focusing microfluidic channel, where the dextran-rich (DEX) and polyethylene glycol-rich (PEG) solutions are introduced as disperse and continuous phases, respectively. To vary the ATPS equilibrium condition, we infuse into a secondary inlet the PEG phase from a different polymer concentration ATPS. We find that the resulting alteration of the continuous PEG phase can cause droplets to shrink or grow by approximately 45 and 30 %, respectively. This volume change is due to water exchange between the disperse DEX and continuous PEG phases, as the system tends towards new equilibria. We also develop a simple model, based on the ATPS binodal curve and tie lines, that predicts the amount of droplet shrinkage or growth, based on the change in the continuous phase PEG concentration. We observe a good agreement between our experimental results and the model. Additionally, we find that, when the continuous phase PEG concentration is reduced such that PEG and DEX phases no longer phase separate, the ATPS droplets are dissolved into the continuous phase. We apply this method to controllably release encapsulated microparticles and cells, and we find that their release occurs within 10 seconds. Our approach uses the dynamic equilibrium of ATPS to control droplet size along the microfluidic channel. By modulating the ATPS equilibrium, we are able to shrink, grow, and dissolve ATPS droplets in situ. We anticipate that this approach may find utility in many biomedical settings, for example, in drug and cell delivery and release applications.

Shrinking, growing, and bursting: microfluidic equilibrium control of water-in-water droplets

Lab on a Chip ◽  
2016 ◽  
Vol 16 (14) ◽  
pp. 2601-2608 ◽  
Author(s):  
Byeong-Ui Moon ◽  
Dae Kun Hwang ◽  
Scott S. H. Tsai
Keyword(s):  
Phase System ◽  
Water Droplets ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Equilibrium Control ◽  
Microfluidic Technique

We demonstrate a new microfluidic technique that controls the shrinking, growing, and bursting of aqueous two phase system (ATPS) droplets.

scholarly journals Preparation, Characterization, and Optimization of an In Vitro C30 Carotenoid Pathway

2005 ◽  
Vol 71 (11) ◽  
pp. 6578-6583 ◽  
Author(s):  
Bosung Ku ◽  
Jae-Cheol Jeong ◽  
Benjamin N. Mijts ◽  
Claudia Schmidt-Dannert ◽  
Jonathan S. Dordick
Keyword(s):  
Phase System ◽  
Reaction Conditions ◽  
Two Phase ◽  
Gene Encoding ◽  
In Situ Extraction ◽  
Steady State Kinetics ◽  
Wide Range ◽  
Carotenoid Synthesis

ABSTRACT The ispA gene encoding farnesyl pyrophosphate (FPP) synthase from Escherichia coli and the crtM gene encoding 4,4′-diapophytoene (DAP) synthase from Staphylococcus aureus were overexpressed and purified for use in vitro. Steady-state kinetics for FPP synthase and DAP synthase, individually and in sequence, were determined under optimized reaction conditions. For the two-step reaction, the DAP product was unstable in aqueous buffer; however, in situ extraction using an aqueous-organic two-phase system resulted in a 100% conversion of isopentenyl pyrophosphate and dimethylallyl pyrophosphate into DAP. This aqueous-organic two-phase system is the first demonstration of an in vitro carotenoid synthesis pathway performed with in situ extraction, which enables quantitative conversions. This approach, if extended to a wide range of isoprenoid-based pathways, could lead to the synthesis of novel carotenoids and their derivatives.

Study on the Role of Surfactants to Aqueous Two-Phase Synthesizing CPAM

2013 ◽  
Vol 781-784 ◽  
pp. 511-514
Author(s):  
Ya Feng Cao ◽  
Mei Jun Qu ◽  
Feng Zhi Tan ◽  
Zhao Li Liu ◽  
Yuan Li
Keyword(s):  
Monomer Conversion ◽  
Continuous Phase ◽  
Ionic Surfactants ◽  
Process Conditions ◽  
Phase System ◽  
Two Phase ◽  
Optimum Reaction ◽  
Optimum Reaction Condition ◽  
Better Than

In this paper,cationic polyacrylamide (CPAM) was synthesized by using aqueous two-phase polymerization. The Role of surfactants to aqueous two-phase synthesizing CPAM was studied, including the effect of the type,the composition and the concentration of the surfactants. The results showed that non-ionic surfactants had a better stabilizing impact on the polymer aqueous two-phase system. And the effect of the compound surfactant was better than that of a single surfactant. Take the chemical compound of Tween80 and OP10 as the polymerization auxiliaries, the optimum reaction condition of synthesis were as follows:wTween80:ѡOP10=1.5,w=1.6%, 50°C.In this process conditions, the distribution coefficient was the most appropriate in the continuous phase, the total monomer conversion rate and the intrinsic viscosity number of the product reached the maximum.

scholarly journals A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones

2021 ◽  
Vol 17 ◽  
pp. 2906-2914
Author(s):  
Yuki Yamamoto ◽  
Akihiro Tabuchi ◽  
Kazumi Hosono ◽  
Takanori Ochi ◽  
Kento Yamazaki ◽  
...  
Keyword(s):  
Large Scale ◽  
Phase System ◽  
Methyl Ethyl ◽  
Two Phase ◽  
One Pot ◽  
Mild Conditions ◽  
Substoichiometric Amount ◽  
Practical Synthesis ◽  
Industrial Use

A simple and efficient method for α-brominating lactones that affords α-bromolactones under mild conditions using tetraalkylammonium hydroxide (R4N+OH−) as a base was developed. Lactones are ring-opened with Br2 and a substoichiometric amount of PBr3, leading to good yields of the corresponding α-bromocarboxylic acids. Subsequent intramolecular cyclization over 1 h using a two-phase system (H2O/CHCl3) containing R4N+OH− afforded α-bromo lactones in good yields. This method can be applied at the 10 mmol scale using simple operations. α-Bromo-δ-valerolactone, which is extremely reactive and difficult to isolate, could be isolated and stored in a freezer for about one week using the developed method. Optimizing the solvent for environmentally friendly large-scale syntheses revealed that methyl ethyl ketone (MEK) was as effective. In addition, in situ-generated α-bromo-δ-valerolactone was directly converted into a sulfur-substituted functional lactone without difficulty by reacting it with a sulfur nucleophile in one pot without isolation. This new bromination system is expected to facilitate the industrial use of α-bromolactones as important intermediates.

Recovery of PEGylated and native lysozyme using an in situ aqueous two-phase system directly from the PEGylation reaction

2017 ◽  
Vol 92 (10) ◽  
pp. 2519-2526 ◽  
Author(s):  
Luis Alberto Mejía-Manzano ◽  
Karla Mayolo-Deloisa ◽  
Calef Sánchez-Trasviña ◽  
José González-Valdez ◽  
Mirna González-González ◽  
...  
Keyword(s):  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System

scholarly journals A Multi-Enzyme Cascade for the Production of High-Value Aromatic Compounds

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1216
Author(s):  
Claudia Engelmann ◽  
Jens Johannsen ◽  
Thomas Waluga ◽  
Georg Fieg ◽  
Andreas Liese ◽  
...  
Keyword(s):  
Cascade Reactions ◽  
Cofactor Regeneration ◽  
Candida Boidinii ◽  
Phase System ◽  
Second Phase ◽  
Aromatic Ester ◽  
Two Phase ◽  
Enzyme Cascade

Cascade reactions are the basis of life in nature and are adapted to research and industry in an increasing manner. The focus of this study is the production of the high-value aromatic ester cinnamyl cinnamate, which can be applied in flavors and fragrances. A three-enzyme cascade was established to realize the synthesis, starting from the corresponding aldehyde with in situ cofactor regeneration in a two-phase system. After characterization of the enzymes, a screening with different organic solvents was carried out, whereby xylene was found to be the most suitable solvent for the second phase. The reaction stability of the formate dehydrogenase (FDH) from Candida boidinii is the limiting step during cofactor regeneration. However, the applied enzyme cascade showed an overall yield of 54%. After successful application on lab scale, the limitation by the FDH was overcome by immobilization of the enzymes and an optimized downstream process, transferring the cascade into a miniplant. The upscaling resulted in an increased yield for the esterification, as well as overall yields of 37%.

Bromination of Butyl Rubber in the Presence of Electrophilic Solvents and Oxidizing Agents

2000 ◽  
Vol 73 (2) ◽  
pp. 356-365 ◽  
Author(s):  
Gabor Kaszas
Keyword(s):  
Organic Phase ◽  
Hydrogen Bromide ◽  
Butyl Rubber ◽  
Phase System ◽  
Two Phase ◽  
Oxidizing Agents ◽  
Consecutive Reactions ◽  
Highly Uniform ◽  
Rate Controlling Step

Abstract Bromination of 1,4-isoprene units in butyl rubber proceeds by substitution leading to the formation of hydrogen bromide as byproduct. In-situ conversion of HBr back to bromine is possible by the use of oxidizing agents but the reaction is very slow and oxidation of the polymer may occur. The reaction is complex and is typically conducted in a two-phase system. It has been found that the rate-controlling step is the bromination of the 1,4-isoprene unit in the organic phase, and not the oxidation of HBr to Br2 in the water phase or the mass transfer of HBr or Br2 between phases. Increasing the electrophilicity of the organic phase dramatically increased the overall rate. A 90–95 wt % conversion of bromine was achieved in one minute. Side or consecutive reactions (oxidation of the polymer, hydrobromination of the unsaturation, rearrangement or dehydrohalogenation of the main product) could be avoided, allowing the synthesis of a highly uniform material.

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