Critical conditions for organic thread cutting under electric fields

Soft Matter ◽  
2021 ◽  
Author(s):  
Shuai Yin ◽  
Yi Huang ◽  
Teck Neng Wong
Keyword(s):  
Electric Fields ◽  
Capillary Number ◽  
Critical Conditions ◽  
Thread Cutting ◽  
On Demand

Critical conditions with electric capillary number are investigated for triggering the on-demand cutting of an organic thread in a microchannel under electric fields.

scholarly journals Optical properties of silver nanocube surfaces obtained by silane immobilization

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Virginia Merk ◽  
Alexander Nerz ◽  
Sebastian Fredrich ◽  
Ulrich Gernert ◽  
Sören Selve ◽  
...  
Keyword(s):  
Electric Fields ◽  
Finite Difference Time Domain ◽  
Simple Approach ◽  
Nano Particle ◽  
Face To Face ◽  
On Demand ◽  
Silver Nanocubes ◽  
Enhancement Factors ◽  
Glass Surfaces ◽  
Difference Time

AbstractSilver nanocubes were synthesized by the polyol method and immobilized on a surface in a simple approach using an aminopropyltriethoxysilane (APTES). The optical and structural properties of the polyvinylpyrrolidone (PVP) stabilized nanocubes were investigated in solution and on glass surfaces. The SERS enhancement factors at two excitation wavelengths for crystal violet were compared with electric fields arising in different nano¬particle configurations using finite-difference time-domain simulations. They are in agreement with the preferred face-to-face orientation in the nanoaggregates on the surfaces. The facile immobilization enables on-demand preparation and use of the nanocubes in real analytical applications.

scholarly journals On-demand hierarchical patterning with electric fields

2014 ◽  
Vol 104 (23) ◽  
pp. 231605 ◽  
Author(s):  
Qiming Wang ◽  
Dominick Robinson ◽  
Xuanhe Zhao
Keyword(s):  
Electric Fields ◽  
On Demand

scholarly journals Selected Results of the Collaborative Research Center "Droplet Dynamics under Extreme Ambient Conditions" SFB/TRR 75

2017 ◽  
Author(s):  
Cameron Tropea ◽  
Bernhard Weigand ◽  
Kathri Schulte
Keyword(s):  
Electric Fields ◽  
Collaborative Research ◽  
High Pressures ◽  
Research Effort ◽  
Research Center ◽  
Critical Conditions ◽  
Aircraft Icing ◽  
Ambient Conditions ◽  
Main Research ◽  
The Impact

The Collaborative Research Center (CRC) SFB-TRR 75 was established in January 2010 to focus on the dynamicsof basic drop processes, and in particular on processes involving extreme boundary conditions, for example, near thermodynamic critical conditions, very low temperatures, under strong electric fields or in situations involving extremely large gradients. The CRC is a joint initiative of the University of Stuttgart, the TU Darmstadt and the German Aerospace Center (DLR) in Lampoldshausen, operating with 17 projects structured into three main research areas and involving researchers from numerous faculties: Mathematics, Chemistry, Electrical Engineering, Aerospace Engineering, Mechanical Engineering, Informatics and Computer Sciences. Some of the topics pursued at the CRC include•The behaviour of supercooled and potentially electrified droplets in clouds•The impact of Supercooled Large Droplets (SLD) on aircraft icing•The behaviour of strongly electrified drops on insulator surfaces, which can be found on high voltagepower lines, affecting the partial discharge behaviour and performance and durability of the insulator.•Trans-critical injection conditions of fuel with flash boiling in rocket combustion chambers•Atomization and vaporization of droplets at high pressures and temperature, as occurring in futurecombustion systemsThis article provides an overview of the projects being carried out at the SFB-TRR 75 and highlights scientific results from selected subprojects. The main purpose of the paper is to familiarize colleagues with this extensive and dedicated research effort in the area of drop dynamics and to motivate and initiate future collaboration with others in this field.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4597

CONTROLLED ELECTRIC FIELD-ASSISTED JETTING FROM VISCOUS AND NANOSUSPENSION MEDIA DROPLETS

NANO ◽  
2006 ◽  
Vol 01 (03) ◽  
pp. 243-250 ◽  
Author(s):  
S. N. JAYASINGHE
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Materials Science ◽  
High Viscosity ◽  
Copper Plate ◽  
Direct Result ◽  
Droplet Volume ◽  
Droplet Deformation ◽  
On Demand ◽  
The Media

This paper reports a study into forming a jet-on-demand to continuous microthreads by subjecting electric fields on high viscosity and low conducting media (concentrated nanosuspensions and dielectric mediums) droplets, placed on a conducting copper plate, which has a similar plate above at a distance of ~ 10 mm. The media used in this investigation has a viscosity ≫ 1000 mPa s and an electrical conductivity ≪ 10-6 Sm-1 and in the case of nanomaterial loading in suspension is 003E; 15 wt.%. The investigation illustrates both the ability to form jets in this configuration and the importance of the volume of media placed as a droplet which has a direct result on the formation of a jet subsequently fragmentating to droplets. At a droplet volume of < Q0, the resting droplet when under the influence of an applied electric field deforms forming a cone, much like those referred to as the "Taylor Cones". On increasing the volume of the droplet to Q0 and applying a voltage of ~ 4.6 kV across the plates, the apex of the cone was observed to pulsate. On further increasing the applied voltage, giving rise to an electric field strength of ~ 0.55 kV/mm, the pulsating apex stabilizes to evolve a stable jet which undergoes instabilities promoting the generation of droplets. Consequently, a fine jet-on-demand is obtained. On increasing the droplet volume to > Q0, forms jets on both plates. The study elucidates the importance of this jetting approach for forming droplet relics containing self-assembled nanoparticles to continuous microthreads from concentrated nanosuspensions and dielectric media for forming structures by deposition that are most useful and have widespread applications in materials science and engineering. Hence, the physical behavior of this droplet deformation — jetting — forming droplets under an imposed field, outlines the discussion presented in this paper.

Electrically controlled rapid release of actives encapsulated in double-emulsion droplets

Lab on a Chip ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 1121-1129 ◽  
Author(s):  
Yankai Jia ◽  
Yukun Ren ◽  
Likai Hou ◽  
Weiyu Liu ◽  
Tianyi Jiang ◽  
...  
Keyword(s):  
Electric Fields ◽  
Double Emulsion ◽  
On Demand ◽  
Emulsion Droplets ◽  
Rapid Release ◽  
Oil In Water ◽  
Double Emulsion Droplets

We utilize electric fields to trigger the on-demand release of different cargos that are encapsulated in water-in-oil-in-water (W/O/W) double-emulsion droplets.

Electrokinetic instabilities of non-dilute colloidal suspensions

2009 ◽  
Vol 619 ◽  
pp. 331-365 ◽  
Author(s):  
GURU NAVANEETHAM ◽  
JONATHAN D. POSNER
Keyword(s):  
Electrical Conductivity ◽  
Electric Fields ◽  
Colloidal Particles ◽  
Volume Fraction ◽  
Flow Instability ◽  
Colloidal Suspensions ◽  
Critical Conditions ◽  
Scaling Analysis ◽  
Average Particle ◽  
Wide Range

An experimental investigation of electrokinetic instabilities (EKIs) of non-dilute colloidal suspensions in microchannels is presented. The addition of charged colloidal particles to a solution can alter the solution's electrical conductivity and permittivity as well as the average particle electrophoretic mobility. In this work, a colloidal (500 nm polystyrene) volume fraction gradient is achieved at the intersection of a Y-shaped polydimethylsiloxane (PDMS) microchannel. The flow becomes unstable when the electroviscous stretching and folding of the conductivity and permittivity interfaces exceed the dissipative effects of viscous forces and particle diffusion. The suspension conductivity as a function of the particle volume fraction is presented. The critical conditions required for flow instability are measured along with a scaling analysis which shows that the flow becomes unstable due to a coupling of applied electric fields and the electrical conductivity and permittivity gradients in the flow. The flow becomes unstable at a critical electric Rayleigh number of Rae = 1.8 × 105 for a wide range of applied electric fields spanning three orders of magnitude and colloid volume fractions varying two orders of magnitude. EKIs of non-dilute colloidal suspensions may be important for applications such as the electrophoretic deposition of micropatterned colloidal assemblies, electrorheological devices and on-chip electrokinetic (EK) manipulation of colloids.

Orientation-On-Demand Thin Films: Curing of Liquid Crystalline Networks in ac Electric Fields

Science ◽  
1996 ◽  
Vol 272 (5259) ◽  
pp. 252-255 ◽  
Author(s):  
H. Korner ◽  
A. Shiota ◽  
T. J. Bunning ◽  
C. K. Ober
Keyword(s):  
Thin Films ◽  
Electric Fields ◽  
Liquid Crystalline ◽  
On Demand ◽  
Ac Electric Fields

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Electron Microscope Observations of Magnetic and Electric Effects

1970 ◽  
Vol 28 ◽  
pp. 430-431
Author(s):  
John Silcox
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Magnetic Image ◽  
Magnetic Effects ◽  
Ferromagnetic Films ◽  
Diffraction Contrast ◽  
Microscope Images ◽  
Electric Effects ◽  
Image Detail

Several aspects of magnetic and electric effects in electron microscope images are of interest and will be discussed here. Clearly electrons are deflected by magnetic and electric fields and can give rise to image detail. We will review situations in ferromagnetic films in which magnetic image effects are the predominant ones, others in which the magnetic effects give rise to rather subtle changes in diffraction contrast, cases of contrast at specimen edges due to leakage fields in both ferromagnets and superconductors and some effects due to electric fields in insulators.

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