Taylor cones in a leaky dielectric liquid under an ac electric field

Abstract

Conical points of a leaky dielectric drop surrounded by a dielectric gas in an external ac electric field are investigated. A novel class of steady conical tips depending on the permittivity ratio and applied signal frequency is presented. It is found that conical solutions with very small angles are possible (angles much smaller than the classical Taylor cone angle 49.3° for a conducting drop in a dc field); this result can be relevant to the observations of small cone angles in Chetwani, Maheshwari, and Chang experiments [N. Chetwani, S. Maheshwari, and H.-C. Chang, Phys. Rev. Lett. 101, 204501 (2008)].

Dripping, jetting and tip streaming

“…In particular, it provides accurate predictions for the steady cone-jet mode of electrospray [104][105][106][107][108][109][110][111][112] and electrospinning [67,77], two techniques reviewed in this paper. It has been used to describe AC electrospray phenomena [113,114], and has been extended to simulate ionic liquid menisci undergoing evaporation of ions [115,116].…”

Dripping, jetting and tip streaming

“…In particular, it provides accurate predictions for the steady cone-jet mode of electrospray (Fernández de la Mora, 2007;Gamero-Castaño and Magnani, 2018;Gañán-Calvo, 1997, 2004aHerrada et al, 2012;Higuera, 2010;Ponce-Torres et al, 2018b) and electrospinning (Carroll and Joo, 2006;Reneker and Yarin, 2008), two techniques reviewed in this paper. It has been used to describe AC electrospray phenomena (Demekhin et al, 2011;Yeo et al, 2004), and has been extended to simulate ionic liquid menisci undergoing evaporation of ions (Coffman et al, 2019;Higuera, 2008) The leaky-dielectric model is not exempt from severe limitations. For instance, its extension to include anisotropic and/or inhomogeneous conductivity can violate the conservation of volumetric charge (∇ • j = 0, j is the current density), which is automatically satisfied for constant scalar conductivity (∇•j = ∇•(KE) = K∇•E = ρ e = 0).…”

Charge-Reduced Particles via Self-Propelled Electrohydrodynamic Atomization for Drug Delivery Applications

“…33,34 Another technique involves applying alternating current (AC) instead of direct current to ES. 35,36 In this AC electrospray, oppositely charged particles are alternatively generated at suitable frequencies so that they can recombine and neutralize each other 37 or by resonating the liquid meniscus at the nozzle tip at very high frequencies. 38,39 Within the field of electrohydrodynamic, there is a need for a solution that allows simultaneous neutralization and delivery of particles.…”

“…For drug delivery by inhalation, atomized drug particles need to be discharged. A technique that has been applied in the literature is to generate ions of opposite charge to neutralize ES particles so that they can escape the effect of reference electrode and can be conveyed to the target. − Typically, an actuator is employed to generate oppositely charged molecules to neutralize the particles from conventional ES. , Another technique involves applying alternating current (AC) instead of direct current to ES. , In this AC electrospray, oppositely charged particles are alternatively generated at suitable frequencies so that they can recombine and neutralize each other or by resonating the liquid meniscus at the nozzle tip at very high frequencies. , Within the field of electrohydrodynamic, there is a need for a solution that allows simultaneous neutralization and delivery of particles.…”