Partner: Jaebeom Lee

Lexington High School (US)

Ostatnie publikacje
1.Nwaji N., Hyojin K., Birhanu Bayissa G., Osial M., Vapaavuori J., Lee J., Giersig M., A Stable Perovskite Sensitized Photonic Crystal P, ChemSusChem, ISSN: 1864-5631, DOI: 10.1002/cssc.202400395, pp.2-9, 2024

Streszczenie:

The slow photon effect in inverse opal photonic crystals
represents a promising approach to manipulate the interactions
between light and matter through the design of material
structures. This study introduces a novel ordered inverse opal
photonic crystal (IOPC) sensitized with perovskite quantum dots
(PQDs), demonstrating its efficacy for efficient visible-lightdriven
H2 generation via water splitting. The rational structural
design contributes to enhanced light harvesting. The sensitization
of the IOPC with PQDs improves optical response performance
and enhances photocatalytic H2 generation under visible
light irradiation compared to the IOPC alone. The designed
photoanode exhibits a photocurrent density of 3.42 mAcm

Słowa kluczowe:

Hydrogen production, inverse opals, perovskite, quantum dots, photocatalysts, photonic crystals

Afiliacje autorów:

Nwaji N.-IPPT PAN
Hyojin K.-other affiliation
Birhanu Bayissa G.-other affiliation
Osial M.-IPPT PAN
Vapaavuori J.-other affiliation
Lee J.-Lexington High School (US)
Giersig M.-IPPT PAN
140p.
2.Nwaji N., Juyong G., My‐Chi N., Huu‐Quang N., Hyojin K., Youngeun C., Youngmi K., Hongxia C., Jaebeom L., Emerging potentials of Fe-based nanomaterials for chiral sensing and imaging, Medicinal Research Review, ISSN: 1098-1128, DOI: 10.1002/med.22003, Vol.44, pp.897-918, 2024

Streszczenie:

Fe-based nanostructures have possessed promising properties that make it suitable for chiral sensing and imaging applications owing to their ultra-small size, non-toxicity, biocompatibility, excellent photostability, tunable fluorescence, and water solubility. This review summarizes the recent research progress in the field of Fe-based nanostructures and places special emphases on their applications in chiral sensing and imaging. The synthetic strategies to prepare the targeted Fe-based structures were also introduced. The chiral sensing and imaging applications of the nanostructures are discussed in details.

Słowa kluczowe:

imaging, metasurfaces, quantum dots, sensing, terahertz

Afiliacje autorów:

Nwaji N.-IPPT PAN
Juyong G.-other affiliation
My‐Chi N.-other affiliation
Huu‐Quang N.-other affiliation
Hyojin K.-other affiliation
Youngeun C.-other affiliation
Youngmi K.-other affiliation
Hongxia C.-other affiliation
Jaebeom L.-Lexington High School (US)
140p.
3.Birhanu Bayissa G., Teshome Tufa L., Nwaji Njemuwa N., Xiaojun H., Lee J., Advances in All‑Solid‑State Lithium–Sulfur Batteries for Commercialization, Nano-Micro Letters, ISSN: 2150-5551, DOI: 10.1007/s40820-024-01385-6, Vol.16, pp.2-38, 2024

Streszczenie:

Solid-state batteries are commonly acknowledged as the forthcoming evolution
in energy storage technologies. Recent development progress for these rechargeable
batteries has notably accelerated their trajectory toward achieving commercial
feasibility. In particular, all-solid-state lithium–sulfur batteries (ASSLSBs) that rely
on lithium–sulfur reversible redox processes exhibit immense potential as an energy
storage system, surpassing conventional lithium-ion batteries. This can be attributed
predominantly to their exceptional energy density, extended operational lifespan, and
heightened safety attributes. Despite these advantages, the adoption of ASSLSBs in the
commercial sector has been sluggish. To expedite research and development in this particular
area, this article provides a thorough review of the current state of ASSLSBs. We
delve into an in-depth analysis of the rationale behind transitioning to ASSLSBs, explore
the fundamental scientific principles involved, and provide a comprehensive evaluation
of the main challenges faced by ASSLSBs. We suggest that future research in this field
should prioritize plummeting the presence of inactive substances, adopting electrodes with optimum performance, minimizing interfacial
resistance, and designing a scalable fabrication approach to facilitate the commercialization of ASSLSBs

Afiliacje autorów:

Birhanu Bayissa G.-other affiliation
Teshome Tufa L.-other affiliation
Nwaji Njemuwa N.-IPPT PAN
Xiaojun H.-other affiliation
Lee J.-Lexington High School (US)
140p.
4.Nwaji N., Fikadu B., Osial M., Moazzami Goudarzi Z., Asgaran S., Teshome Tufa L., Lee J., Giersig M., Disentangling the catalytic origin in defect engineered 2D NiCoMoS@Ni(CN)2 core-shell heterostructure for energy-saving hydrazine-assisted water oxidation, International Journal of Hydrogen Energy, ISSN: 0360-3199, DOI: 10.1016/j.ijhydene.2024.08.432, Vol.86, pp.554-563, 2024

Streszczenie:

The major hindrance to efficient electrocatalytic hydrogen generation from water electrolysis is the sluggish kinetics with corresponding large overvoltage of oxygen evolution reaction. Herein, we report a defective 2D NiCoMoS@Ni(CN)2 core-shell heterostructure derived from Hofmann-type MOF as an efficient and durable high-performance noble metal-free electrocatalyst for hydrazine oxidation reaction (HzOR) in alkaline media. The sluggish oxygen evolution reaction was replaced with a more thermodynamically favourable HzOR, enabling energy-saving electrochemical hydrogen production with 2D NiCoMoS@Ni(CN)2 acting as a bifunctional electrocatalyst for anodic HzOR and cathodic hydrogen generation. Operating at room temperature, the two-electrode electrolyzer delivers 100 mA cm−2 from a cell voltage of just 257 mV, with strong long-term electrochemical durability and nearly 100% Faradaic efficiency for hydrogen evolution in 1.0 M KOH aqueous solution with 0.5 M hydrazine. The density functional theory (DFT) was employed to investigate the origin of catalytic performance and showed that high vacancy creation within the heterointerface endowed NiCoMoS@Ni(CN)2 with favourable functionalities for excellent catalytic performance.

Słowa kluczowe:

Defect engineering, Core-shell, Electrocatalyst, Hydrazine oxidation, Heterostructure

Afiliacje autorów:

Nwaji N.-IPPT PAN
Fikadu B.-other affiliation
Osial M.-IPPT PAN
Moazzami Goudarzi Z.-IPPT PAN
Asgaran S.-other affiliation
Teshome Tufa L.-other affiliation
Lee J.-Lexington High School (US)
Giersig M.-IPPT PAN
140p.
5.Nwaji N., Fikadu B., Osial M., Gicha B.B., Warczak M., Fan H., Lee J., Giersig M., Atomically dispersed ruthenium in transition metal double layered hydroxide as a bifunctional catalyst for overall water splitting, RENEWABLE ENERGY, ISSN: 0960-1481, DOI: 10.1016/j.renene.2024.121307, Vol.235, pp.1-10, 2024

Streszczenie:

Efficient and sustainable energy conversion depends on the rational design of single-atom catalysts. The control of the active sites at the atomic level is vital for electrocatalytic materials in alkaline and acidic electrolytes. Moreover, fabrication of effective catalysts with a well-defined surface structure results in an in-depth understanding of the catalytic mechanism. Herein, a single atom ruthenium dispersed in nickel-cobalt layered hydroxide (Ru-NiCo LDH) is reported. Through the precise controlling of the atomic dispersion and local coordination environment, Ru-NiCo LDH//Ru-NiCo LDH provides an ultra-low overpotential of 1.45 mV at 10 mA cm−2 for the overall water splitting, which surpasses that of the state-of-the-art Pt/C/RuO2 redox couple. Density functional theory calculations show that Ru-NiCo LDH optimizes hydrogen evolution intermediate adsorption energies and promotes O-O coupling at a Ru-O active site for oxygen evolution, while Ni serves as the water dissociation site for effective water splitting. As a potential model, Ru-NiCo LDH shows enhanced water splitting performance with potential for the development of promising water-alkaline catalysts.

Afiliacje autorów:

Nwaji N.-IPPT PAN
Fikadu B.-other affiliation
Osial M.-IPPT PAN
Gicha B.B.-other affiliation
Warczak M.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Fan H.-other affiliation
Lee J.-Lexington High School (US)
Giersig M.-IPPT PAN
140p.
6.Nwaji N., Getasew Mulualem Z., Juyong G., Hyojin K., Lemma Tushome T., Yujin C., Mahedra G., Hyeyoung S., Jaebeom L., Dimeric NiCo single-atom anchored on ultrathin N-doped 2D molybdenum carbide boosted performance in solid-state supercapacitor, Journal of Energy Storage, ISSN: 2352-152X, DOI: 10.1016/j.est.2024.110671, Vol.83, pp.1-10, 2024

Streszczenie:

Tuning the electronic structure of single-atom catalysts through dimeric single-atom formation could be an innovative approach to increasing their energy storage activity, but the process of achieving this is challenging. In this study, we designed a simple technique to obtain Nisingle bondCo single atom dimers (SADs) anchored on N-doped molybdenum carbide (N-Mo2C) through in-situ encapsulation of Nisingle bondCo into molybdenum polydopamine, followed by annealing with optimal tuning of nitrogen dopant. The Nisingle bondCo atomic level coordination was confirmed with X-ray absorption spectroscopy. When used as energy storage supercapacitor, The NiCo-SADs showed enhanced specific capacity (1004.8 F g−1 at 1 A g−1), enhanced rate capability (75 %), and exceptional cycling stability (93.6 % with 98.5 % coulombic efficiency) via a dominant capacitive charge storage. The augmented charge storage characteristics are attributed to the collaborative features of the active Nisingle bondCo constituents acting as electron reservoir for effective adsorption of HO− ion during the electrochemical process. The DFT study showed thermodynamically favorable OH− adsorption between the three metal bridges that promoted redox reaction kinetics and enhanced conductivity for the NiCo-SADs. When using N-Mo2C as the anode to fabricate hybrid supercapacitors, the device exhibits high energy density of 69.69 Wh kg−1 at power density of 8200 W kg−1, respectively and shows excellent long-term cycling stability (93.42 % after 3000 cycles), which affirms the potential of the assembled device for applications in solid state supercapacitors.

Afiliacje autorów:

Nwaji N.-IPPT PAN
Getasew Mulualem Z.-other affiliation
Juyong G.-other affiliation
Hyojin K.-other affiliation
Lemma Tushome T.-other affiliation
Yujin C.-other affiliation
Mahedra G.-other affiliation
Hyeyoung S.-other affiliation
Jaebeom L.-Lexington High School (US)
100p.
7.Birhanu Bayissa G., Teshome Tufa L., Mahendra G., Lee Y., Fikadu Banti B., Nwaji Njoku N., You S., Lee J., Oxygen Vacancy Generation and Stabilization in Layered NiFeCo Double Hydroxide Nanosheets for a Highly Efficient Oxygen Evolution Reaction, ACS Applied Nano Materials, ISSN: 2574-0970, DOI: 10.1021/acsanm.4c01840, Vol.8, pp.A-K, 2024

Streszczenie:

Oxygen vacancy (Vo) is ubiquitous, playing a critical role in tuning the electronic configuration and optimizing the adsorption of adsorbates in the oxygen evolution reaction (OER) process. However, fine control over the density and stabilization of Vo is a big challenge in the highly oxidizing environment of OER. Herein, we have fabricated bulk NiFeCo (layered double hydroxide) LDHs via the hydrothermal method and exfoliated them into thin sheets rich with Vo using high-energy Ar-plasma. We doped fluoride to simultaneously modulate the charge distribution of surrounding atoms and stabilize Vo by taking advantage of the extremely high electronegativity and similar ion diameter to oxygen of fluoride. The material exhibited OER activity with a low overpotential of 200 mV at 10 mA cm–2 and a Tafel slope of 34.6 mV dec–1. Density functional theory (DFT) calculations support the claim that Vo and fluoride substantially increase NiFeCo LDH OER activity by modifying the electronic structures of the catalytically active sites.

Słowa kluczowe:

Electrocatalyst, Double layered hydroxide, oxygen evolution reaction, oxygen vacancy, stabilization

Afiliacje autorów:

Birhanu Bayissa G.-other affiliation
Teshome Tufa L.-other affiliation
Mahendra G.-other affiliation
Lee Y.-other affiliation
Fikadu Banti B.-other affiliation
Nwaji Njoku N.-IPPT PAN
You S.-other affiliation
Lee J.-Lexington High School (US)
8.Nwaji Njemuwa N., Juyong G., Mahendra G., Hyojin K., Adewale Hammed P., Sharan A., Singh N., Lee J., Defect engineered Fe3C@NiCo2S4 trojan nanospike derived from Metal Organic framework as Advanced electrode material for Hybrid supercapacitor., ACS Applied Materials and Interfaces, ISSN: 1944-8244, DOI: 10.1021/acsami.3c04635, Vol.15, No.29, pp.34779-34788, 2023

Streszczenie:

The rational synthesis and tailoring of metal-organic frameworks (MOFs) with multifunctional micro/nanoarchitectures have emerged as a subject of significant academic interest owing to their promising potential for utilization in advanced energy storage devices. Herein, we explored a category of three-dimensional (3D) NiCo2S4 nanospikes that have been integrated into a 1D Fe3C microarchitecture using a chemical surface transformation process. The resulting electrode materials, i.e., Fe3C@NiCo2S4 nanospikes, exhibit immense potential for utilization in high-performance hybrid supercapacitors. The nanospikes exhibit an elevated specific capacity (1894.2 F g-1 at 1 A g-1), enhanced rate capability (59%), and exceptional cycling stability (92.5% with 98.7% Coulombic efficiency) via a charge storage mechanism reminiscent of a battery. The augmented charge storage characteristics are attributed to the collaborative features of the active constituents, amplified availability of active sites inherent in the nanospikes, and the proficient redox chemical reactions of multi-metallic guest species. When using nitrogen-doped carbon nanofibers as the anode to fabricate hybrid supercapacitors, the device exhibits high energy and power densities of 62.98 Wh kg-1 and 6834 W kg-1, respectively, and shows excellent long-term cycling stability (95.4% after 5000 cycles), which affirms the significant potential of the proposed design for applications in hybrid supercapacitors. The DFT study showed the strong coupling of the oxygen from the electrolyte OH- with the metal atom of the nanostructures, resulting in high adsorption properties that facilitate the redox reaction kinetics.

Słowa kluczowe:

defect engineering,Nanospike,advanced electrode,hybrid,MOF,Supercapacitor

Afiliacje autorów:

Nwaji Njemuwa N.-other affiliation
Juyong G.-other affiliation
Mahendra G.-other affiliation
Hyojin K.-IPPT PAN
Adewale Hammed P.-other affiliation
Sharan A.-other affiliation
Singh N.-other affiliation
Lee J.-Lexington High School (US)
200p.
9.Mahendra G., Huu-Quang N., Sohyun K., Birhanu Bayissa G., Teshome Tufa L., Nwaji Njemuwa N., My-Chi Thi N., Juyong G., Lee J., Rugged forest morphology of magnetoplasmonic nanorods that collect maximum light for photoelectrochemical water splitting, Nano Micro Small Journal, ISSN: 1613-6829, DOI: 10.1002/smll.202302980, Vol.19, pp.1-14, 2023

Streszczenie:

A feasible nanoscale framework of heterogeneous plasmonic materials and
proper surface engineering can enhance photoelectrochemical (PEC)
water-splitting performance owing to increased light absorbance, efficient
bulk carrier transport, and interfacial charge transfer. This article introduces a
new magnetoplasmonic (MagPlas) Ni-doped Au@FexOy nanorods (NRs)
based material as a novel photoanode for PEC water-splitting. A two stage
procedure produces core–shell Ni/Au@FexOy MagPlas NRs. The first-step is
a one-pot solvothermal synthesis of Au@FexOy. The hollow FexOy nanotubes
(NTs) are a hybrid of Fe2O3 and Fe3O4, and the second-step is a sequential
hydrothermal treatment for Ni doping. Then, a transverse magnetic
field-induced assembly is adopted to decorate Ni/Au@FexOy on FTO glass to
be an artificially roughened morphologic surface called a rugged forest,
allowing more light absorption and active electrochemical sites. Then, to
characterize its optical and surface properties, COMSOL Multiphysics
simulations are carried out. The core–shell Ni/Au@FexOy MagPlas NRs
increase photoanode interface charge transfer to 2.73 mAcm−2 at 1.23 V RHE.
This improvement is made possible by the rugged morphology of the NRs,
which provide more active sites and oxygen vacancies as the hole transfer
medium. The recent finding may provide light on plasmonic photocatalytic
hybrids and surface morphology for effective PEC photoanodes.

Afiliacje autorów:

Mahendra G.-other affiliation
Huu-Quang N.-other affiliation
Sohyun K.-other affiliation
Birhanu Bayissa G.-other affiliation
Teshome Tufa L.-other affiliation
Nwaji Njemuwa N.-IPPT PAN
My-Chi Thi N.-other affiliation
Juyong G.-other affiliation
Lee J.-Lexington High School (US)
200p.
10.Nwaji N., Akinoglu E.M., Lin Q., Teshome Tufa L., Sharan A., Singh N., Wang X., Giersig M., Lee J., Surface Modulation of Fe3O4 Confined in Porous Molybdenum-Based Nanoplatform for Enhanced Hydrogen Production, Energy Technology, ISSN: 2194-4296, DOI: 10.1002/ente.202201061, Vol.11, No.2, pp.2201061-1-9, 2023

Streszczenie:

The integration of different precursor components to form single nanostructures via one-step synthesis process is mostly restricted by the compatibility and complexity of components. Herein, a highly uniform, spherical, hollowed, and hierarchical iron oxide-wrapped Mo–polydopamine is synthesized using a one-pot liquid-phase reaction at room temperature. Mo2C is doped with Fe3O4 to harness the rich electrons in Fe dopants for effective lowering of the unoccupied d-orbitals in Mo. The surface conductivity of the as-prepared nanostructures is enhanced by decorating them with gold nanoparticles utilizing strong interaction of Au and amine. The nanocomposites are converted into carbidic hollowed structures via an annealing process without any distortion in morphology. The well-organized structure and nanosize of the particles provide efficient catalytic performance for hydrogen evolution reaction in acidic media. MoFe–C@Au exhibits a very positive onset potential of 2 mV, low Tafel slope of 50.1 mV dec^-1, and remarkable long- term stability.

Słowa kluczowe:

electrocatalysts,hierarchical syntheses,hydrogen evolution,molybdenum,polydopamine

Afiliacje autorów:

Nwaji N.-other affiliation
Akinoglu E.M.-University of Melbourne (AU)
Lin Q.-other affiliation
Teshome Tufa L.-other affiliation
Sharan A.-other affiliation
Singh N.-other affiliation
Wang X.-other affiliation
Giersig M.-IPPT PAN
Lee J.-Lexington High School (US)
100p.
11.Cheru Fekadu M., Bedasa Abdisa G., Fedlu Kedir S., Birhanu Bayissa G., Nwaji N., Lemma Teshome T., Jaebeom L., Ni-Based Ultrathin Nanostructures for Overall Electrochemical Water Splitting, Material Chemistry Frontiers, ISSN: 2052-1537, DOI: 10.1039/D2QM00964A, Vol.7, pp.194-215, 2023

Streszczenie:

Hydrogen produced by electrochemical water splitting is considered to be a sustainable fuel source, an
ideal way to solve the energy problem and its environmental challenges. However, industrial production
of hydrogen from water splitting is mainly hindered by sluggish kinetics of the oxygen evolution reaction
(OER) at the anode and the hydrogen evolution reaction (HER) at the cathode in an alkaline solution due
to the difficulty in forming binding protons. Thus, the construction of a highly active and cost-effective
catalyst with abundant oxygen vacancies is critical for enhancing the reaction efficiency and decreasing
the required overpotential. Due to earth-abundance and electrocatalytic activities, Ni-based ultrathin
nanostructures (Ni-utNSs) have attracted immense attention for overall water splitting. Herein, we have
presented a complete summary of recent advancements in Ni-utNSs for overall electrochemical water
splitting. After discussing unique advances in Ni-utNSs, we discussed their properties and crystal
structures. The HER, OER, and oxygen reduction reaction (ORR) mechanisms were briefly discussed. We
also discussed several Ni-utNS manufacturing techniques, as well as in situ and ex situ characterization
and computer modeling. Furthermore, the electrochemical water splitting of Ni-utNSs is addressed. This
review can help readers understand the recent progress of Ni-utNS catalysts and gain insight into the
rational design of Ni-utNS catalysts with high electrocatalytic activity.

Afiliacje autorów:

Cheru Fekadu M.-other affiliation
Bedasa Abdisa G.-other affiliation
Fedlu Kedir S.-other affiliation
Birhanu Bayissa G.-other affiliation
Nwaji N.-IPPT PAN
Lemma Teshome T.-other affiliation
Jaebeom L.-Lexington High School (US)
12.Nwaji Njemuwa N., Hyojin K., Mahendra G., Teshome Tufa L., Juyong G., Sharan A., Singh N., Lee J., Sulfur vacancy induced Co3S4@CoMo2S4 nanocomposite as functional electrode for high performance supercapacitor, Journal of Materials Chemistry A, ISSN: 2050-7488, DOI: 10.1039/d2ta08820g, Vol.11, pp.3640-3652, 2023

Streszczenie:

Vacancy engineering offers an attractive approach to improving the surface properties and electronic
structure of transition metal nanomaterials. However, simple and cost-effective methods for introducing
defects into nanomaterials still face great challenges. Herein, we propose a facile room temperature
two-step technique that utilizes Fe as the dopant to enhance S vacancies in cobalt-based metal–organic
frameworks (MOFs). The Fe–Co-MOF was converted into a hollow Fe–Co3S4 confined in CoMo2S4 to
form Fe–Co3S4@CoMo2S4 nanosheets. The as-prepared material showed enhanced charge storage
kinetics and excellent properties as an electrode material for supercapacitors. The obtained
nanostructure displayed a high specific capacitance (980.3 F g−1 at 1 A g−1) and excellent cycling stability
(capacity retention of 96.5% after 6000 cycles at 10 A g−1). Density functional theory (DFT) calculations
show that introducing defects into the nanostructures leads to more electrons appearing near the Fermi
level, which is beneficial for electron transfer during electrochemical processes. Thus, this work provides
a rational cost-effective strategy for introducing defects into transition metal sulfides and may serve as
a potential means to prepare electrode materials for energy storage.

Afiliacje autorów:

Nwaji Njemuwa N.-other affiliation
Hyojin K.-other affiliation
Mahendra G.-other affiliation
Teshome Tufa L.-other affiliation
Juyong G.-other affiliation
Sharan A.-other affiliation
Singh N.-other affiliation
Lee J.-Lexington High School (US)
13.Achadu Ojodomo J., Nwaji N., Lee D., Lee J., Akinoglu E.M., Giersig M., Park Enoch Y., 3D hierarchically porous magnetic molybdenum trioxide@gold nanospheres as a nanogap-enhanced Raman scattering biosensor for SARS-CoV-2, Nanoscale Advances, ISSN: 2516-0230, DOI: 10.1039/d1na00746g, Vol.4, pp.871-883, 2022

Streszczenie:

The global pandemic of COVID-19 is an example of how quickly a disease-causing virus can take root and threaten our civilization. Nowadays, ultrasensitive and rapid detection of contagious pathogens is in high demand. Here, we present a novel hierarchically porous 3-dimensional magnetic molybdenum trioxide–polydopamine-gold functionalized nanosphere (3D mag-MoO3–PDA@Au NS) composed of plasmonic, semiconductor, and magnetic nanoparticles as a multifunctional nanosculptured hybrid. Based on the synthesized 3D mag-MoO3–PDA@Au NS, a universal “plug and play” biosensor for pathogens is proposed. Specifically, a magnetically-induced nanogap-enhanced Raman scattering (MINERS) detection platform was developed using the 3D nanostructure. Through a magnetic actuation process, the MINERS system overcomes Raman signal stability and reproducibility challenges for the ultrasensitive detection of SARS-CoV-2 spike protein over a wide dynamic range up to a detection limit of 10−15 g mL−1. The proposed MINERS platform will facilitate the broader use of Raman spectroscopy as a powerful analytical detection tool in diverse fields.

Afiliacje autorów:

Achadu Ojodomo J.-other affiliation
Nwaji N.-other affiliation
Lee D.-other affiliation
Lee J.-Lexington High School (US)
Akinoglu E.M.-University of Melbourne (AU)
Giersig M.-IPPT PAN
Park Enoch Y.-other affiliation
20p.
14.Abate A.R., Poitzsch A., Hwang Y., Lee J., Czerwińska J., Weitz D.A., Impact of inlet channel geometry on microfluidic drop formation, PHYSICAL REVIEW E, ISSN: 1539-3755, DOI: 10.1103/PhysRevE.80.026310, Vol.80, pp.26310-5, 2009

Streszczenie:

We study the impact of inlet channel geometry on microfluidic drop formation. We show that drop makers with T-junction style inlets form monodisperse emulsions at low and moderate capillary numbers and those with Flow-Focus style inlets do so at moderate and high capillary numbers. At low and moderate capillary number, drop formation is dominated by interfacial forces and mediated by the confinement of the microchannels; drop size as a function of flow-rate ratio follows a simple functional form based on a blocking-squeezing mechanism. We summarize the stability of the drop makers with different inlet channel geometry in the form of a phase diagram as a function of capillary number and flow-rate ratio.

Afiliacje autorów:

Abate A.R.-University of California (US)
Poitzsch A.-Pinkerton Academy (US)
Hwang Y.-St. Paul’s School (US)
Lee J.-Lexington High School (US)
Czerwińska J.-IPPT PAN
Weitz D.A.-Harvard University (US)
32p.