Breakup Length of Electrified Liquid Jets: Scaling Laws and Applications

Ismail, A. Said; Xia, Huihui; Stark, John

doi:10.1103/physrevapplied.10.064010

Cited by 14 publications

(22 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some common solvents used to prepare precursor solutions for E-spray are ethanol, ethylene glycol (EG), polyethylene glycol (PEG), propanol, and N,N-dimethylformamide (DMF) ( Table 2). [78] These droplets are charged, and during the E-spray, they go through four phases as they travel from nozzle to substrate: 1) solvent evaporation, 2) coulombic explosion, 3) solidification, and 4) deposition. As the droplets progress toward the substrate, evaporation continues and the size of the droplet shrinks, increasing the charge density.…”

Section: Tuning the Surface Roughness By Means Of A Solventmentioning

confidence: 99%

Electrostatically Sprayed Nanostructured Electrodes for Energy Conversion and Storage Devices

Joshi

Samuel

Kim

et al. 2021

Adv Funct Materials

View full text Add to dashboard Cite

The electrostatic spray method is a promising nonvacuum technique for efficient deposition of thin films from solutions or dispersions. The multitude of electrostatic spray process parameters, including surface tension, viscosity, and conductivity of the liquid, applied voltage, nozzle size, and flow rate, make electrostatic spray deposition very versatile for the morphological engineering of nanostructured films. The current state-of-the-art in electrostatic spraying can produce exceptional morphologies. Such tailoring of morphologies is notably useful in electrochemical applications where high electrolyte-accessible surface area often improves performance. Interesting morphologies of metal oxides and their composites are highlighted, including nanopillars, nanoferns, and porous microspheres produced by electrostatic spraying to enhance energy conversion and storage performance. The physics associated with the electrostatic spray process and morphology control using it are also presented. The manuscript highlights the potential of electrospray processing for producing thin films of controlled microstructure, from ultrasmooth layers in organic photovoltaics and perovskite photovoltaics to hierarchical nanostructured films for anodes and photoanodes. It aims to help researchers appreciate essential aspects of electrostatic spray deposition efficiency, process control, and morphology engineering for energy conversion (e.g., solar cell, fuel cell, and photoelectrochemical cell) and energy storage (e.g., lithium-ion battery and supercapacitor) electrodes.

show abstract

Section: Tuning the Surface Roughness By Means Of A Solventmentioning

confidence: 99%

Electrostatically Sprayed Nanostructured Electrodes for Energy Conversion and Storage Devices

Joshi

Samuel

Kim

et al. 2021

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…An important element of the present analysis is the scale v r1 of the perturbation velocity. As is similarly done in the temporal stability analysis [31], we assume that the residence time in the jet scales as the time for the transverse perturbation to cause the free surface pinching, i.e., L j /V j ∼ D j /v r1 . Since D j ∼ l z and v r1 ∼ v z1 , we get l z /L j ∼ v z1 /V j , which implies (i) that the perturbation caused by the breakup can propagate upstream a distance much smaller than the jet length, and (ii) that v z1 ∼ v r1 ∼ Q/(L j l z ) ∼ Q/(L j D j ).…”

Section: A Simplified Approachmentioning

confidence: 99%

“…Indeed, the temporal linear stability analysis presents two important drawbacks: (i) the initial perturbation amplitude is a free parameter, which implies that the prefactor of the jet length scaling cannot be predicted; and (ii) the model does not contemplate the energy feedback coming from the jet breakup, as will be described below. Using the temporal stability analysis, Ismail et al [31] derived two scalings for the breakup length of jets under the action of an axial electric field in the limits of small and large Reynolds numbers. Despite the drawbacks mentioned above, good agreement between those scalings and experimental data was found.…”

Section: Introductionmentioning

confidence: 99%

The Natural Breakup Length of a Steady Capillary Jet: Application to Serial Femtosecond Crystallography

et al. 2021

View full text Add to dashboard Cite

One of the most successful ways to introduce samples in Serial Femtosecond Crystallography has been the use of microscopic capillary liquid jets produced by gas flow focusing, whose length-to-diameter ratio and velocity are essential to fulfill the requirements of the high pulse rates of current XFELs. In this work, we demonstrate the validity of a classical scaling law with two universal constants to calculate that length as a function of the liquid properties and operating conditions. These constants are determined by fitting the scaling law to a large set of experimental and numerical measurements, including previously published data. Both the experimental and numerical jet lengths conform remarkably well to the proposed scaling law. We show that, while a capillary jet is a globally unstable system to linear perturbations above a critical length, its actual and shorter long-term average intact length is determined by the nonlinear perturbations coming from the jet breakup itself. Therefore, this length is determined solely by the properties of the liquid, the average velocity of the liquid and the flow rate expelled. This confirms the very early observations from Smith and Moss 1917, Proc R Soc Lond A Math Phys Eng, 93, 373, to McCarthy and Molloy 1974, Chem Eng J, 7, 1, among others, while it contrasts with the classical conception of temporal stability that attributes the natural breakup length to the jet birth conditions in the ejector or small interactions with the environment.

show abstract

“…9 (b)). Indeed, this approach has been demonstrated to achieve line width below 10 μm using nanoparticle inks [34].…”

Section: ⅲ Scaling For Predicting the Jet Instability Modementioning

confidence: 99%

Scaling Laws for Transition from Varicose to Whipping Instabilities in Electrohydrodynamic Jetting

2019

Self Cite

View full text Add to dashboard Cite

Whether an electrified jet breaks up whilst the jet maintains a straight line (varicose), or alternatively the jet trajectory becomes chaotic (whipping), depends on the competition of the interfacial forces. Starting from the competition of normal stresses on the jet surface, we derive scaling laws in different electro-hydrodynamic operating regimes as a function of fluid properties and the flow rate. The onset of whipping occurs when this scaling function reaches a threshold, which is independent of the electric field strength. However, experimental evidence indicates that this onset condition applies only when the viscosity and electrical conductivity of a liquid are small enough. As a result, we further introduce a general parameter to incorporate viscous effects into the scaling law. A unified threshold value for this parameter is found through a substantial number of experiments for liquids having a wide range of properties, and under a wide variety of operational conditions of flow rate.

show abstract

Breakup Length of Electrified Liquid Jets: Scaling Laws and Applications

Cited by 14 publications

References 20 publications

Electrostatically Sprayed Nanostructured Electrodes for Energy Conversion and Storage Devices

Electrostatically Sprayed Nanostructured Electrodes for Energy Conversion and Storage Devices

The Natural Breakup Length of a Steady Capillary Jet: Application to Serial Femtosecond Crystallography

Scaling Laws for Transition from Varicose to Whipping Instabilities in Electrohydrodynamic Jetting

Contact Info

Product

Resources

About