scholarly journals Microfluidic Formation of Honeycomb-Patterned Droplets Bounded by Interface Bilayers via Bimodal Molecular Adsorption

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 701 ◽  
Author(s):  
Shougo Fujiwara ◽  
Kan Shoji ◽  
Chiho Watanabe ◽  
Ryuji Kawano ◽  
Miho Yanagisawa

Assembled water-in-oil droplets bounded by lipid bilayers are used in synthetic biology as minimal models of cell tissue. Microfluidic devices successfully generate monodispersed droplets and assemble them via droplet interface bilayesr (DIB) formation. However, a honeycomb pattern of DIB-bounded droplets, similar to epithelial tissues, remains unrealized because the rapid DIB formation between the droplets hinders their ability to form the honeycomb pattern. In this paper, we demonstrate the microfluidic formation of a honeycomb pattern of DIB-bounded droplets using two surfactants with different adsorption rates on the droplet surface. A non-DIB forming surfactant (sorbitan monooleate, Span 80) was mixed with a lipid (1,2-dioleoyl-sn-glycero-3-phosphocholine, PC), whose adsorption rate on the droplet surface and saturated interfacial tension were lower than those of Span 80. By changing the surfactant composition, we established the conditions under which the droplets initially form a honeycomb pattern and subsequently adhere to each other via DIB formation to minimize the interfacial energy. In addition, the reconstituted membrane protein nanopores at the DIBs were able to transport molecules. This new method, using the difference in the adsorption rates of two surfactants, allows the formation of a honeycomb pattern of DIB-bounded droplets in a single step, and thus facilitates research using DIB-bounded droplet assemblies.

Author(s):  
Kai Hashino ◽  
Daiya Mombayashi ◽  
Yuto Nakatani ◽  
Azusa Oshima ◽  
Masumi Yamaguchi ◽  
...  

Abstract Lipid bilayers suspended over microwells on Si substrates are promising platforms for nanobiodevices that mimic cell membranes. Using the biotin-avidin interaction, we have succeeded in selectively arranging vesicles on the freestanding region of a lipid bilayer. When ternary lipid mixtures of saturated lipid, unsaturated lipid, and cholesterol are used, they separate into liquid-order (Lo) and liquid-crystalline (Lα) domains. A freestanding lipid bilayer prefers the Lα-phase over the Lo-phase because of the difference in their flexibility. In addition, the type of biotinylated lipid determines whether it is localized in the Lα-phase domain or the Lo-phase domain. As a result, the biotinylated unsaturated lipids localized in the Lα-phase domain aggregate in the freestanding lipid bilayer, and vesicles labeled with biotin selectively bind to the freestanding lipid bilayer by the biotin-avidin interaction. This technique helps to introduce biomolecules into the freestanding lipid bilayer of nanobiodevices via vesicles.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1107
Author(s):  
Seong-Pil Kang ◽  
Dongwon Lee ◽  
Jong-Won Lee

Kinetic hydrate inhibitors (KHI) and anti-agglomerants (AA) rather than thermodynamic hydrate inhibitors (THI) are often used for flow assurance in pipelines. This is because they require much lower dosages than thermodynamic inhibitors. Although the hydrate-phase equilibria are not affected, KHI and AA prevent the formed hydrate crystals from growing to a bulky state causing pipeline blockage. However, these KHIs might have huge environmental impact due to leakages from the pipelines. In this study, two biodegradable AA candidates from natural sources (that is, lecithin and lanolin) are proposed and their performances are evaluated by comparing them with and without a conventional AA (Span 80, sorbitan monooleate). At 30% and 50% water cut, the addition of AA materials was found to enhance the flow characteristics substantially in pipelines and hardly affected the maximum value of the rotational torque, respectively. Considering the cost-effective and environmental advantages of the suggested AA candidates over a conventional AA such as Span 80, the materials are thought to have potential viability for practical operation of oil and gas pipelines. However, additional investigations will be done to clarify the optimum amounts and the action mechanisms of the suggested AAs.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5207
Author(s):  
Minkyu Ju ◽  
Jeongeun Park ◽  
Young Hyun Cho ◽  
Youngkuk Kim ◽  
Donggun Lim ◽  
...  

Recently, selective emitter (SE) technology has attracted renewed attention in the Si solar cell industry to achieve an improved conversion efficiency of passivated-emitter rear-contact (PERC) cells. In this study, we presented a novel technique for the SE formation by controlling the surface morphology of Si wafers. SEs were formed simultaneously, that is, in a single step for the doping process on different surface morphologies, nano/micro-surfaces, which were formed during the texturing processes; in the same doping process, the nano- and micro-structured areas showed different sheet resistances. In addition, the difference in sheet resistance between the heavily doped and shallow emitters could be controlled from almost 0 to 60 Ω/sq by changing the doping process conditions, pre-deposition and driving time, and temperature. Regarding cell fabrication, wafers simultaneously doped in the same tube were used. The sheet resistance of the homogeneously doped-on standard micro-pyramid surface was approximately 82 Ω/sq, and those of the selectively formed nano/micro-surfaces doped on were on 62 and 82 Ω/sq, respectively. As a result, regarding doped-on selectively formed nano/micro-surfaces, SE cells showed a JSC increase (0.44 mA/cm2) and a fill factor (FF) increase (0.6%) with respect to the homogeneously doped cells on the micro-pyramid surface, resulting in about 0.27% enhanced conversion efficiency.


2014 ◽  
Vol 67 (2) ◽  
Author(s):  
Norasikin Othman ◽  
Ooi Zing-Yi ◽  
Norlisa Harruddin ◽  
Raja Norimie ◽  
Norela Jusoh ◽  
...  

Nowadays, water pollution has become major issue especially dye contaminated wastewaters from the textile industry. Dye causes serious environmental pollution and health problems. The removal of color from dye-contaminated wastewaters in the related industries becomes a major concern all over the world. In this research, several parameters of dye extraction and recovery in the continuous emulsion liquid membrane (ELM) process were investigated. This process consisted of three phases which are external (feed) phase, membrane phase and internal phase. The membrane phase was prepared by dissolving extractant bis(2-ethylhexyl)phosphoric acid (D2EHPA) and hydrophobic surfactant sorbitan monooleate (Span 80) in kerosene as diluents. The internal phase consisted of an aqueous solution of sulfuric acid (H2SO4). The important parameters governing the extraction process of dye such as stirring speed, initial dye concentration, Span 80 concentration and treat ratio (volume ratio of emulsion to external phase) were studied. The results showed that the optimum condition for 25ppm initial concentration of dye extraction are 250 rpm stirring speed, 5% (w/v) Span 80 and treat ratio 1:5. At this condition, the percentage of dye extraction, stripping and recovery were 98%, 82% and 81% respectively. Hence, continuous ELM technique is proven to be a very promising technique in industrial wastewater treatment and recovery of dye.


1985 ◽  
Vol 6 (2) ◽  
pp. 183-186 ◽  
Author(s):  
J. N. Mkhize ◽  
A. P. Gupta

AbstractThe use of surfactants and their blends to improve the penetration of two insect growth regulators (IGRs; hydroprene and R-20458) into wheat kernels was investigated. It was found that formulation of IGRs with a surfactant, Tween-85 (polyoxyethylene trioleate), increased mortality and/or effectiveness of the IGRs. Formulation of hydroprene with a blend of Span-80 (sorbitan monooleate) with Tween-80 (polyoxyethylene monooleate) produced results comparable to those by hydroprene with Tween-85. However, formulations of IGRs with surfactants with high or low hydrophile-lipophile balance (HLB), failed to provide suitable control of the weevil, probably due to the type of emulsions formed. The same results were obtained with hydroprene formulations with blends of Spans and Tweens, even though their HLBs were close to that of Tween-85. Residual half-life for hydroprene was about three months; formulations with Tween-85 or a blend of Span-80 did not enhance the residual activity for hydroprene in wheat.


1992 ◽  
Vol 258 ◽  
Author(s):  
Lynnita Knoch ◽  
N. David Theodore ◽  
Gordon Tam ◽  
Ron Pennell

ABSTRACTIn this study, amorphous silicon and polycrystalline silicon films were implanted with arsenic and subjected to varied low temperature (<900°C) anneal conditions and characterized using TEM. The microstructure is of interest for later correlation with electrical measurements. The amorphous deposition produces larger, more irregular grains with more strain than does the polysilicon deposition for a single-step rapid thermal anneal (RTA) cycle. This can be explained by the number of critical nucleii and the rate of grain growth. The sheet resistivity, as measured by four-point probe, correlates to the deposition conditions. A two-stage anneal makes the grains less irregular by reducing the roughness of the grains and decreasing the strain in the grains. For a given deposition condition, the final microstructure is most strongly influenced by the first anneal. The second anneal produces no clear change in grain size. 800°C anneals result in larger grains than 900°C anneals. This is explained by the presence of less critical nucleii for 800°C anneals. In comparing short and long durations of RTA, the short duration produced slightly larger grains than the long duration RTA due to greater nucleation in the longer RTA wafers. In the case of RTA versus furnace anneals, RTA produces larger, more irregular grains, with more strain in the grains. A model in terms of the size of critical nucleii is used to explain the difference.


2002 ◽  
Vol 20 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Li Defu ◽  
Wang Jinqu

The equilibrium adsorption and diffusion properties of ethylene, oxygen and carbon dioxide gases on two kinds of molecular sieve at 25°C were measured by gravimetric methods using a Cahn-2000 electrobalance. On both molecular sieves, the equilibrium adsorption capacity of ethylene was larger than that of oxygen and close to that of carbon dioxide, indicating that it would not be possible to remove oxygen and carbon dioxide gases from their mixture with ethylene in order to effect recovery of the latter via equilibrium separation methods. However, during the early stages of adsorption, the adsorption rates of carbon dioxide and oxygen were faster than that of ethylene thereby suggesting recovery of the latter from the gaseous mixture via kinetic separation based on the difference in adsorption diffusivity. Such separation was conducted using a two-bed column pressure swing adsorption arrangement with the effects of the experimental conditions on the separation being investigated. Oxygen and carbon dioxide may be adsorbed and removed from the gaseous mixture, leaving the output gases rich in ethylene.


2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Allaberen Ashyralyev ◽  
Mehmet Emin San

A single-step difference scheme for the numerical solution of the nonlocal-boundary value problem for stochastic parabolic equations is presented. The convergence estimate for the solution of the difference scheme is established. In application, the convergence estimates for the solution of the difference scheme are obtained for two nonlocal-boundary value problems. The theoretical statements for the solution of this difference scheme are supported by numerical examples.


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