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Droplet formation in oval microchannels with a double T junction: a CFD and experimental study. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2021. [DOI: 10.1007/s43153-021-00133-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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2
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Binyaminov H, Abdullah F, Zargarzadeh L, Elliott JAW. Thermodynamic Investigation of Droplet-Droplet and Bubble-Droplet Equilibrium in an Immiscible Medium. J Phys Chem B 2021; 125:8636-8651. [PMID: 34310143 DOI: 10.1021/acs.jpcb.1c02877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the absence of external fields, interfacial tensions between different phases dictate the equilibrium morphology of a multiphase system. Depending on the relative magnitudes of these interfacial tensions, a composite system made up of immiscible fluids in contact with one another can exhibit contrasting behavior: the formation of lenses in one case and complete encapsulation in another. Relatively simple concepts such as the spreading coefficient (SC) have been extensively used by many researchers to make predictions. However, these qualitative methods are limited to determining the nature of the equilibrium states and do not provide enough information to calculate the exact equilibrium geometries. Moreover, due to the assumptions made, their validity is questionable at smaller scales where pressure forces due to curvature of the interfaces become significant or in systems where a compressible gas phase is present. Here we investigate equilibrium configurations of two fluid drops suspended in another fluid, which can be seen as a simple building block of more complicated systems. We use Gibbsian composite-system thermodynamics to derive equilibrium conditions and the equation acting as the free energy (thermodynamic potential) for this system. These equations are then numerically solved for an example system consisting of a dodecane drop and an air bubble surrounded by water, and the relative stability of distinct equilibrium shapes is investigated based on free-energy comparisons. Quantitative effects of system parameters such as interfacial tensions, volumes, and the scale of the system on geometry and stability are further explored. Multiphase systems similar to the ones analyzed here have broad applications in microfluidics, atmospheric physics, soft photonics, froth flotation, oil recovery, and some biological phenomena.
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Affiliation(s)
- Hikmat Binyaminov
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9
| | - Fahim Abdullah
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9
| | - Leila Zargarzadeh
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9
| | - Janet A W Elliott
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9
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Porto Santos T, Cejas CM, Cunha RL, Tabeling P. Unraveling driving regimes for destabilizing concentrated emulsions within microchannels. SOFT MATTER 2021; 17:1821-1833. [PMID: 33399611 DOI: 10.1039/d0sm01674h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Coalescence is the most widely demonstrated mechanism for destabilizing emulsion droplets in microfluidic chambers. However, we find that depending on the channel wall surface functionalization, surface zeta potential, type of surfactant, characteristics of the oil as a dispersed phase, or even the presence of externally-induced stress, other different destabilization mechanisms can occur in subtle ways. In general, we observe four regimes leading to destabilization of concentrated emulsions: (i) coalescence, (ii) emulsion bursts, (iii) a combination of the two first mechanisms, attributed to the simultaneous occurrence of coalescence and emulsion bursts; and (iv) compaction of the droplet network that eventually destabilizes to fracture-like behavior. We correlate various physico-chemical properties (zeta potential, contact angle, interfacial tension) to understand their respective influence on the destabilization mechanisms. This work provides insights into possible ways to control or inflict emulsion droplet destabilization for different applications.
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Affiliation(s)
- Tatiana Porto Santos
- Department of Food Engineering, Faculty of Food Engineering, University of Campinas, Rua Monteiro Lobato, 80-CEP 13083-862 Campinas, Brazil. and Microfluidics, MEMS, Nanostructures Laboratory, CNRS Chimie Biologie Innovation (CBI) UMR 8231, Institut Pierre Gilles de Gennes (IPGG), ESPCI Paris, PSL Research University, 6 rue Jean Calvin 75005, Paris, France.
| | - Cesare M Cejas
- Microfluidics, MEMS, Nanostructures Laboratory, CNRS Chimie Biologie Innovation (CBI) UMR 8231, Institut Pierre Gilles de Gennes (IPGG), ESPCI Paris, PSL Research University, 6 rue Jean Calvin 75005, Paris, France.
| | - Rosiane Lopes Cunha
- Department of Food Engineering, Faculty of Food Engineering, University of Campinas, Rua Monteiro Lobato, 80-CEP 13083-862 Campinas, Brazil.
| | - Patrick Tabeling
- Microfluidics, MEMS, Nanostructures Laboratory, CNRS Chimie Biologie Innovation (CBI) UMR 8231, Institut Pierre Gilles de Gennes (IPGG), ESPCI Paris, PSL Research University, 6 rue Jean Calvin 75005, Paris, France.
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4
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Lu JM, Wang HF, Pan JZ, Fang Q. Research Progress of Microfluidic Technique in Synthesis of Micro/Nano Materials. ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21030086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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5
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Three-dimensional lattice Boltzmann simulation of Janus droplet formation in Y-shaped co-flowing microchannel. Chem Eng Sci 2020. [DOI: 10.1016/j.ces.2020.115819] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Haney B, Werner JG, Weitz DA, Ramakrishnan S. Absorbent-Adsorbates: Large Amphiphilic Janus Microgels as Droplet Stabilizers. ACS APPLIED MATERIALS & INTERFACES 2020; 12:33439-33446. [PMID: 32598144 DOI: 10.1021/acsami.0c11408] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Microgel particles are cross-linked polymer networks that absorb certain liquids causing network expansion. The type of swelling fluid and extent of volume change depends on the polymer-liquid interaction and the network's cross-link density. These colloidal gels can be used to stabilize emulsion drops by adsorbing to the interface of two immiscible fluids. However, to enhance the adsorption abilities of these predominantly hydrophilic gel particles, some degree of hydrophobicity is needed. An amphiphilic Janus microgel with spatially distinct lipophilic and hydrophilic sides is desired. Here, we report the fabrication of poly(ethylene glycol) diacrylate/poly(propylene glycol) diacrylate Janus microgels (JM) using microfluidic drop making. The flow streams of the two separate and immiscible monomer solutions are brought into contact and intersected by a third immiscible fluid in a flow-focusing junction to form Janus droplets. The individual droplets are cross-linked via UV irradiation to form monodispersed microgel particles with opposing hydrophilic and hydrophobic 3D-networked polymer matrices. By combining two chemically different polymer gel networks, an amphiphilic emulsion stabilizer is formed that adsorbs to the oil-water interface while its faces absorb their respective water or hydrocarbon solvents. The resulting water-in-oil emulsions are stabilized and destabilized via a thermal-responsive hydrogel. Stimuli-responsive droplets are demonstrated by adding a short-chain oligo ethylene glycol acrylate molecule to the hydrogel formulation on the Janus microgel particle. Droplets stabilized by these particles experience a sudden increase in droplet diameter around 60 °C. This work with absorbent particles may prove useful for applications in bio catalysis, fuel production, and oil transportation.
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Affiliation(s)
- Bobby Haney
- Department of Chemical and Biomedical Engineering, FAMU-FSU Engineering, Tallahassee, Florida 32310, United States
| | - Jörg G Werner
- Department of Mechanical Engineering and Division of Materials Science and Engineering, Boston University, Boston, Massachusetts 02215, United States
| | | | - Subramanian Ramakrishnan
- Department of Chemical and Biomedical Engineering, FAMU-FSU Engineering, Tallahassee, Florida 32310, United States
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Zhang F, Jiang L, Zeng C, Wang C, Wang J, Ke X, Zhang L. Complex emulsions for shape control based on mass transfer and phase separation. SOFT MATTER 2020; 16:5981-5989. [PMID: 32543634 DOI: 10.1039/d0sm00862a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Complex emulsions are used to fabricate new morphologies of multiple Janus droplets, evolving from non-engulfing to complete engulfing core/shell configuration. The produced droplets contain an aqueous phase of dextran (DEX) solution and an oil phase, which is mixed with ethoxylated trimethylolpropane triacrylate (ETPTA) and poly(ethylene glycol) diacrylate (PEGDA). The PEGDA in the oil phase is transferred into the aqueous phase to form complex morphologies due to the phase separation of PEGDA and DEX. The effects are investigated including the ratio of oil to aqueous phase, the content of initial PEGDA, DEX and surfactants, and the type of surfactants. DEX/PEGDA-ETPTA core/shell-single phase Janus droplets are formed with an increasing engulfed oil droplet into the aqueous droplet while the ratio of oil to aqueous phase increases or the initial PEGDA content increases. The high DEX content leads to the DEX-PEGDA-ETPTA doublet Janus. The use of surfactants polyglycerol polyricinoleate (PGPR) and Span 80 results in the formation of DEX/PEGDA/ETPTA single core/double shell and DEX/PEGDA-ETPTA core/shell-single phase Janus droplets, respectively. These complex emulsions are utilized to fabricate solid particles of complex shapes. This method contributes to new material design underpinned by mass transfer and phase separation, which can be extended to other complex emulsion systems.
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Affiliation(s)
- Feng Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, No. 30, Puzhu Road(s), Nanjing 211816, P. R. China.
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Santos TP, Costa ALR, Michelon M, Costa LP, Cunha RL. Development of a microfluidic route for the formation of gellan-based microgels incorporating jabuticaba (Myrciaria cauliflora) extract. J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2019.109884] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Haney B, Werner JG, Weitz DA, Ramakrishnan S. Stimuli responsive Janus microgels with convertible hydrophilicity for controlled emulsion destabilization. SOFT MATTER 2020; 16:3613-3620. [PMID: 32250375 DOI: 10.1039/d0sm00255k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Although the utilization of rigid particles can afford stable emulsions, some applications require eventual emulsion destabilization to release contents captured in the particle-covered droplet. This destabilizing effect is achieved when using stabilizers that respond to controlled changes in environment. Microgels can be synthesized as stimuli responsive polymeric gel networks that adsorb to oil/water interfaces and stabilize emulsions. These particles are commonly hydrogels that swell and collapse in water in response to environmental changes. However, amphiphilic functionality is desired to enhance the adsorption abilities of these hydrogels while maintaining their stimuli responsivity. Microfluidic techniques are used to synthesize Janus microgels with two opposing stimuli responsive hemispheres. The particles have a temperature responsive domain connected to a pH responsive network where each side changes its hydrophilicity in response to a change in temperature or pH, respectively. The Janus microgels are amphiphilic in acidic conditions at 19 °C and alkaline conditions at 40 °C, while the opposite conditions cause a reduction of the amphiphilicity. By stabilizing emulsions with these dual responsive microgels, "smart" droplets that respond to environmental cues are formed. Emulsion droplets remain stable with smaller diameters when aqueous solution conditions favor amphiphilic particles yet, coalesce to larger droplets upon changing pH or temperature. These responsive Janus microgels represent the advancing technology of responsive droplets and demonstrate the applicability of microgels as emulsion stabilizers.
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Affiliation(s)
- Bobby Haney
- Department of Chemical and Biomedical Engineering, FAMU-FSU Engineering, Tallahassee, Florida 32310, USA.
| | - Jörg G Werner
- Department of Mechanical Engineering and Division of Materials Science and Engineering, Boston University, Boston, Massachusetts 02215, USA and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - David A Weitz
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Subramanian Ramakrishnan
- Department of Chemical and Biomedical Engineering, FAMU-FSU Engineering, Tallahassee, Florida 32310, USA.
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Ding C, Ge L, Jin H, Bian Q, Guo R. Janus emulsions formed with organic solvents as inner phases. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.123947] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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11
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Temperature and composition induced morphology transition of Cerberus emulsion droplets. J Colloid Interface Sci 2019; 554:210-219. [PMID: 31301521 DOI: 10.1016/j.jcis.2019.07.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/04/2019] [Accepted: 07/06/2019] [Indexed: 11/23/2022]
Abstract
HYPOTHESIS Various advanced geometries are endowed by the unique structure of "three rooms" of immiscible oils composing the Cerberus droplets. Adjustable interfacial properties and tunable volume ratio in the four-liquid system render it possible to realize the controlled morphology transition by the variation of temperature and emulsion composition. EXPERIMENTS Cerberus emulsions are prepared in batch scale by traditional one-step vortex mixing, employing the oil combinations of methacryloxypropyl dimethyl silicone (DMS)/2-(perfluorooctyl) ethyl methacrylate (PFOEMA)/vegetable oil (VO). Emulsifier of pluoronic F127, a temperature sensitive surfactant is applied. Stereoscopic topological phase diagram as functions of temperature and composition are plotted. Numerical calculations on the droplet morphology including interface curvature, contact angle, and volume fraction of each domain are performed. FINDINGS Four primary regions with specific morphologies, i.e. "VO > DMS < PFOEMA", "VO > DMS > PFOEMA", "VO < DMS > PFOEMA", and finally "VO < DMS < PFOEMA" are obtained. Extended volume ratio range of three lobes, from about 0.03 to 23.3, is achieved and precisely controlled based on the three-phase diagram. What is more, the structural features are found to be thermodynamically determined by the minimization of interfacial energy, though the emulsion is prepared kinetically by vortex mixing. The findings are attractive in the fields of materials synthesis and microreactors.
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Haney B, Chen D, Cai LH, Weitz D, Ramakrishnan S. Millimeter-Size Pickering Emulsions Stabilized with Janus Microparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4693-4701. [PMID: 30840480 DOI: 10.1021/acs.langmuir.9b00058] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The ability to make stable water-in-oil and oil-in-water millimeter-size Pickering emulsions is demonstrated using Janus particles-particles with distinct surface chemistries. The use of a highly cross-linked hydrophobic polymer network and the excellent water-wetting nature of a hydrogel as the hydrophobic and hydrophilic sides, respectively, permit distinct wettability on the Janus particle. Glass capillary microfluidics allows the synthesis of Janus particles with controlled sizes between 128 and 440 μm and control over the hydrophilic-to-hydrophobic domain volume ratio of the particle from 0.36 to 12.77 for a given size. It is shown that the Janus particle size controls the size of the emulsion drops, thus providing the ability to tune the structure and stability of the resulting emulsions. Stability investigations using centrifugation reveal that particles with the smallest size and a balanced hydrophilic-to-hydrophobic volume ratio (Janus ratio) form emulsions with the greatest stability against coalescence. Particles eventually jam at the interface to form nonspherical droplets. This effect is more pronounced as the hydrogel volume is increased. The large Janus particles permit facile visualization of particle-stabilized emulsions, which result in a better understanding of particle stabilization mechanisms of formed emulsions.
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Affiliation(s)
- Bobby Haney
- Department of Chemical and Biomedical Engineering , FAMU-FSU Engineering , Tallahassee , Florida 32310 , United States
| | - Dong Chen
- College of Chemical and Biological Engineering , Zhejiang University , Zhejiang 310027 , China
| | - Li-Heng Cai
- School of Engineering and Applied Science , University of Virginia , Charlottesville , Virginia 22903 , United States
| | - David Weitz
- Physics , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Subramanian Ramakrishnan
- Department of Chemical and Biomedical Engineering , FAMU-FSU Engineering , Tallahassee , Florida 32310 , United States
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Versatile reconfigurable glass capillary microfluidic devices with Lego® inspired blocks for drop generation and micromixing. J Colloid Interface Sci 2019; 542:23-32. [DOI: 10.1016/j.jcis.2019.01.119] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 11/18/2022]
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Xue D, Meng QB, Song XM. Magnetic-Responsive Janus Nanosheets with Catalytic Properties. ACS APPLIED MATERIALS & INTERFACES 2019; 11:10967-10974. [PMID: 30793582 DOI: 10.1021/acsami.8b21012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this article, we describe a method to fabricate magnetic-responsive Janus nanosheets with catalytic properties via the surface protection method. Fe3O4 nanoparticles and PW12O403--based ionic liquid are located on the two opposite sides of the Janus nanosheets, respectively. The Janus nanosheets are characterized by Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and ζ-potential analyses. They are used as recyclable catalysts to the esterification reaction of methanol and oleic acid for their magnetic-responsive and catalytic properties. The esterification ratio is up to 80% and there is nearly no change when Fe3O4 nanoparticles/PW12O403--based ionic liquid composite nanosheets were recycled four times.
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Affiliation(s)
- Dan Xue
- Liaoning Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry , Liaoning University , Shenyang 110036 , China
| | - Qing Bo Meng
- Liaoning Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry , Liaoning University , Shenyang 110036 , China
| | - Xi-Ming Song
- Liaoning Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry , Liaoning University , Shenyang 110036 , China
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Ge L, Jin H, Li X, Wei D, Guo R. Batch-Scale Preparation of Reverse Janus Emulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3490-3497. [PMID: 30702288 DOI: 10.1021/acs.langmuir.9b00061] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A strategy is proposed to produce novel (W1 + W2)/O reverse Janus emulsions in batch scale simply by one-step vortex mixing. Aqueous two-phase systems (ATPSs), i.e., two immiscible aqueous phases dominated by sodium carbonate and ethanol, respectively, are employed as inner phases and vegetable oil (VO) as continuous phase. The geometry of the Janus droplets, although formed as a result of a kinetic process, is tunable and controllable easily by adjusting the composition of ATPSs based on three-phase diagram. Reducing the relatively higher water/oil interfacial tensions to a comparable value of water/water interface, which is extremely low in order of 0.1 mN/m, is achieved by employing a fluorocarbon surfactant. Moreover, the weak acid-induced deprotonation of the fatty acid in the VO phase due to the presence of sodium carbonate also contributes to the lower water/oil interfacial tension. The total free-energy values calculated verify the overwhelmingly favored Janus geometry, which indicates that this topology is heavily preformed as local equilibrium state. The approach proposed provides vehicle for the synthesis of aqueous-based materials with various advanced morphologies.
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Affiliation(s)
- Lingling Ge
- School of Chemistry and Chemical Engineering , Yangzhou University , Yangzhou 225009 , China
| | - Haimei Jin
- School of Chemistry and Chemical Engineering , Yangzhou University , Yangzhou 225009 , China
| | - Xia Li
- School of Chemistry and Chemical Engineering , Yangzhou University , Yangzhou 225009 , China
| | - Duo Wei
- School of Chemistry and Chemical Engineering , Yangzhou University , Yangzhou 225009 , China
| | - Rong Guo
- School of Chemistry and Chemical Engineering , Yangzhou University , Yangzhou 225009 , China
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Equilibrium morphology of gas–liquid Janus droplets: A numerical analysis of buoyancy effect. Chin J Chem Eng 2018. [DOI: 10.1016/j.cjche.2018.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Wang L, Yu L, Zeng C, Wang C, Zhang L. Fabrication of PAA-PETPTA Janus Microspheres with Respiratory Function for Controlled Release of Guests with Different Sizes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:7106-7116. [PMID: 29801415 DOI: 10.1021/acs.langmuir.8b01055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Poly(acrylic acid)-poly(ethoxylated trimethylolpropane triacrylate) (PAA-PETPTA) Janus microspheres with "respiratory" function for controlled release were prepared by polymerization of acrylic acid-ethoxylated trimethylolpropane triacrylate (AA-ETPTA) Janus microdroplets in a continuous oil phase in a simple capillary-based microfluidic device with the assistance of UV radiation. The flow rate ratios of AA and ETPTA phases and surfactant content in the continuous oil phase have a significant effect on the structure of the Janus microspheres. PAA part in the Janus microspheres has respiratory function for loading and release due to the different stimuli responses to different pHs. The hollow structure of PETPTA part with different sizes of opening serves as the host materials for PAA and could control release rate further due to the different opening sizes. The obtained PAA-PETPTA Janus microspheres showed high rhodamine B (RhB) loading of 860 mg g-1 and different controlled-release behavior in water with different pHs. The release rate increases with the increase of pH and the contact area of PAA part with water. The maximum controlled-release time for RhB was about 3 h in water with pH of 5. In addition, the Janus microspheres also showed controlled-release behavior for larger size guests, e.g., 150 nm polystyrene beads, which indicated a wide range of application. The loading and release behaviors for guests, for instance, for RhB, have almost no change even after six times of reuse, which indicated a high stability.
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Affiliation(s)
- Liwei Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering , Nanjing Tech University , Nanjing 210009 , P. R. China
| | - Liang Yu
- Chemical Technology , Luleå University of Technology , SE-971 87 Luleå , Sweden
| | - Changfeng Zeng
- College of Mechanical and Power Engineering , Nanjing Tech University , No. 5 Xin Mofan Road , Nanjing 210009 , P. R. China
| | - Chongqing Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering , Nanjing Tech University , Nanjing 210009 , P. R. China
| | - Lixiong Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering , Nanjing Tech University , Nanjing 210009 , P. R. China
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Chen A, Ge XH, Chen J, Zhang L, Xu JH. Multi-functional micromotor: microfluidic fabrication and water treatment application. LAB ON A CHIP 2017; 17:4220-4224. [PMID: 29143043 DOI: 10.1039/c7lc00950j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Micromotors are important for a wide variety of applications. Here, we develop a microfluidic approach for one-step fabrication of a Janus self-propelled micromotor with multiple functions. By fine tuning the fabrication parameters and loading functional nanoparticles, our micromotor reaches a high speed and achieves an oriented function to promote the water purification efficiency and recycling process.
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Affiliation(s)
- Anqi Chen
- Department of Chemical Engineering, The State Key Lab of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. C.
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Ge XH, Geng YH, Chen J, Xu JH. Smart Amphiphilic Janus Microparticles: One-Step Synthesis and Self-Assembly. Chemphyschem 2017; 19:2009-2013. [DOI: 10.1002/cphc.201700838] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/02/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Xue-Hui Ge
- The State Key Lab of Chemical Engineering; Department of Chemical Engineering; Tsinghua University; Beijing 100084 China
| | - Yu-Hao Geng
- The State Key Lab of Chemical Engineering; Department of Chemical Engineering; Tsinghua University; Beijing 100084 China
| | - Jian Chen
- The State Key Lab of Chemical Engineering; Department of Chemical Engineering; Tsinghua University; Beijing 100084 China
| | - Jian-Hong Xu
- The State Key Lab of Chemical Engineering; Department of Chemical Engineering; Tsinghua University; Beijing 100084 China
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Guo P, Zeng C, Wang C, Zhang L. Magnetic ionic liquid‐water Janus droplets: Preparation, structure and morphology adjustment and magnetic manipulation. AIChE J 2017. [DOI: 10.1002/aic.15672] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Peng Guo
- The State Key Laboratory of Materials‐Oriented Chemical Engineering and College of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing210009 P.R. China
| | - Changfeng Zeng
- College of Mechanical and Power EngineeringNanjing Tech UniversityNo. 5 Xin Mofan RdNanjing210009 P.R. China
| | - Chongqing Wang
- The State Key Laboratory of Materials‐Oriented Chemical Engineering and College of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing210009 P.R. China
| | - Lixiong Zhang
- The State Key Laboratory of Materials‐Oriented Chemical Engineering and College of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing210009 P.R. China
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He Y, Savagatrup S, Zarzar LD, Swager TM. Interfacial Polymerization on Dynamic Complex Colloids: Creating Stabilized Janus Droplets. ACS APPLIED MATERIALS & INTERFACES 2017; 9:7804-7811. [PMID: 28198607 DOI: 10.1021/acsami.6b15791] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Complex emulsions, including Janus droplets, are becoming increasingly important in pharmaceuticals and medical diagnostics, the fabrication of microcapsules for drug delivery, chemical sensing, E-paper display technologies, and optics. Because fluid Janus droplets are often sensitive to external perturbation, such as unexpected changes in the concentration of the surfactants or surface-active biomolecules in the environment, stabilizing their morphology is critical for many real-world applications. To endow Janus droplets with resistance to external chemical perturbations, we demonstrate a general and robust method of creating polymeric hemispherical shells via interfacial free-radical polymerization on the Janus droplets. The polymeric hemispherical shells were characterized by optical and fluorescence microscopy, scanning electron microscopy, and confocal laser scanning microscopy. By comparing phase diagrams of a regular Janus droplet and a Janus droplet with the hemispherical shell, we show that the formation of the hemispherical shell nearly doubles the range of the Janus morphology and maintains the Janus morphology upon a certain degree of external perturbation (e.g., adding hydrocarbon-water or fluorocarbon-water surfactants). We attribute the increased stability of the Janus droplets to (1) the surfactant nature of polymeric shell formed and (2) increase in interfacial tension between hydrocarbon and fluorocarbon due to polymer shell formation. This finding opens the door of utilizing these stabilized Janus droplets in a demanding environment.
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Affiliation(s)
- Yuan He
- Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology , Cambridge Massachusetts 02139, United States
| | - Suchol Savagatrup
- Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology , Cambridge Massachusetts 02139, United States
| | - Lauren D Zarzar
- Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology , Cambridge Massachusetts 02139, United States
- Department of Materials Science and Engineering and Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Timothy M Swager
- Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology , Cambridge Massachusetts 02139, United States
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23
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Ge XH, Geng YH, Zhang QC, Shao M, Chen J, Luo GS, Xu JH. Four reversible and reconfigurable structures for three-phase emulsions: extended morphologies and applications. Sci Rep 2017; 7:42738. [PMID: 28198444 PMCID: PMC5309921 DOI: 10.1038/srep42738] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/13/2017] [Indexed: 12/15/2022] Open
Abstract
Here in this article, we classify and conclude the four morphologies of three-phase emulsions. Remarkably, we achieve the reversible transformations between every shape. Through theoretical analysis, we choose four liquid systems to form these four morphologies. Then monodispersed droplets with these four morphologies are formed through a microfluidic device and captured in a petri-dish. By replacing their ambient solution of the captured emulsions, in-situ morphology transformations between each shape are achieved. The process is well recorded through photographs and videos and they are systematical and reversible. Finally, we use the droplets structure to form an on-off switch to start and shut off the evaporation of one volatile phase to achieve the process monitoring. This could be used to initiate and quench a reaction, which offers a novel idea to achieve the switchable and reversible reaction control in multiple-phase reactions.
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Affiliation(s)
- Xue-Hui Ge
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
| | - Yu-Hao Geng
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
| | - Qiao-Chu Zhang
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
| | - Meng Shao
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
| | - Jian Chen
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
| | - Guang-Sheng Luo
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
| | - Jian-Hong Xu
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)
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24
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Abstract
Engineering characteristics of liquid–liquid microflow and its advantages in chemical reactions.
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Affiliation(s)
- Kai Wang
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Liantang Li
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Pei Xie
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Guangsheng Luo
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
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25
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Nisisako T. Recent advances in microfluidic production of Janus droplets and particles. Curr Opin Colloid Interface Sci 2016. [DOI: 10.1016/j.cocis.2016.05.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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26
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Li M, Li D. Fabrication and electrokinetic motion of electrically anisotropic Janus droplets in microchannels. Electrophoresis 2016; 38:287-295. [DOI: 10.1002/elps.201600310] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 07/29/2016] [Accepted: 07/30/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Mengqi Li
- Department of Mechanical and Mechatronics Engineering; University of Waterloo; Waterloo Canada
| | - Dongqing Li
- Department of Mechanical and Mechatronics Engineering; University of Waterloo; Waterloo Canada
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