Effect of ion partitioning on the electrostatics of soft particles with a volumetrically charged core

Ganjizade, Ardalan; Ashrafizadeh, Seyed Nezameddin; Sadeghi, Arman

doi:10.1016/j.elecom.2017.09.017

Cited by 45 publications

(26 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is worth nothing that the fluid viscosities of the electrolyte solution layer and PEL are different for high grafting densities owing to hydration effects [ 40 , 41 , 42 ]. The ion partitioning and hydration effects significantly impact the electrostatics of soft surfaces and the electrokinetic phenomena inside soft channels [ 43 ]. Functionalized micro/nanochannels with dense polyelectrolyte layers were reviewed by Ashrafizadeh et al [ 44 , 45 ], which could realize preferable electrostatic characteristics of the working fluid.…”

Section: Introductionmentioning

confidence: 99%

Space Electroosmotic Thrusters in Ion Partitioning Soft Nanochannels

Zheng

Jian

2021

Micromachines

View full text Add to dashboard Cite

Space electroosmotic thrusters (EOTs) are theoretically investigated in a soft charged nanochannel with a dense polyelectrolyte layer (PEL), which is considered to be more realistic than a low-density PEL. When the PEL is dense, its permittivity is smaller than the one of the electrolyte solution layer, leading to rearrangement of ions in the channel, which is denoted as the ion partitioning effect. It is noted that fluid viscosity becomes high within the PEL owing to the hydration effect. An analytical solution for electroosmotic velocity through the channel is obtained by utilizing the Debye–Hückel linearization assumption. Based on the fluid motion, thruster performances, including thrust, specific impulse, thrust-to-power ratio, and efficiency, are calculated. The ion partitioning effect leads to enhancement of the thruster velocity, while increase of the dynamic viscosity inside the PEL reduces the flow rate of the fluid. Therefore, these performances are further impacted by the dense soft material, which are discussed in detail. Moreover, changes or improvements of the thruster performances from the dense PEL to the weak PEL are presented and compared, and distributions of various energy items are also provided in this study. There is a good result whereby the increase in electric double layer thickness promotes the development of thruster performances. Ultimately, the simulated EOTs produce thrust of about 0 to 20 μN and achieve thruster efficiency of 90.40%, while maintaining an appropriate thrust–power ratio of about 1.53 mN/W by optimizing all design parameters.

show abstract

Section: Introductionmentioning

confidence: 99%

Space Electroosmotic Thrusters in Ion Partitioning Soft Nanochannels

Zheng

Jian

2021

Micromachines

View full text Add to dashboard Cite

show abstract

“…Such an assumption is certainly valid for dilute polyelectrolyte systems [33] but it becomes questionable for sufficiently dense polymeric layers where the dielectric permittivity is generally different from that of water. The inner core and the outer shell of composite soft particles are made of polyelectrolytic materials whose dielectric constant may differ from that of bulk electrolyte solution depending on material composition and density [34–36]. For membrane materials, this permittivity is lower than that of water [37].…”

Section: Introductionmentioning

confidence: 99%

“…For membrane materials, this permittivity is lower than that of water [37]. In turn, the differentiated permittivities of the polymer layer and the solvent may have a significant impact on the electrophoretic properties of soft particles [34–35] or on the electrohydrodynamics of soft nanochannels [36]. Indeed, they generate a difference of Born energies between the polymeric and aqueous phases, which in turn reduces the penetration of mobile ions within the polymeric material or, equivalently, reduces the electrostatic softness of the particles.…”

Section: Introductionmentioning

confidence: 99%

Effects of dielectric gradients‐mediated ions partitioning on the electrophoresis of composite soft particles: An analytical theory

2020

View full text Add to dashboard Cite

In this work, we report original analytical expressions defining the electrophoretic mobility of composite soft particles comprising an inner core and a surrounding polymer shell with differentiated permeabilities to ions from aqueous background electrolyte and to fluid flow developed under applied DC field conditions. The existence of dielectric permittivity gradients operational at the core/shell and shell/solution interfaces is accounted for within the Debye-Hückel approximation and flat plate configuration valid in the thin double layer regime. The proposed electrophoretic mobility expressions, applicable to weakly to moderately charged particles with size well exceeding the Debye layer thickness, involve the relevant parameters describing the particle core/shell structure and the electrohydrodynamic features of the core and shell particle components. It is shown that the analytical expressions reported so far in literature for the mobility of hard (impermeable) or porous particles correspond to asymptotic limits of the more generic results detailed here. The impacts of dielectric-mediated effects of ions partitioning between bulk solution and particle body on the electrophoretic response are further discussed. The obtained expressions pave the way for a refined quantitative, analytical interpretation of electrophoretic mobility data collected on soft (nano)particles (e.g., functionalized dendrimers and multilayered polyelectrolytic particles) or biological cells (e.g., viruses) for which the classical hard core-soft shell representation is not appropriate.

show abstract

“…Most of the previous studies have considered the dielectric permittivity of the PE to be the same as that of the adjoining electrolyte solution, which is justified only when the polymer density of the PE is low . Since the dielectric permittivity of the gel is less than that of the surrounding solution, the effective permittivity of the PE is smaller than that of the solution . Young et al.…”

Section: Introductionmentioning

confidence: 99%

“… studied the ion partitioning effect on electrophoresis of a soft particle through the Debye‐Hückel approximation under a thin Debye layer consideration. All these studies suggest that the ion partitioning effect is an important electrokinetic phenomenon involving two neighboring media with different dielectric permittivity. Previous studies dealing with the ion partitioning effect on electrophoresis neglected the double layer polarization and relaxation effects thus, valid for the low charge and weak electric field condition with thinner Debye layer assumption.…”

Section: Introductionmentioning

confidence: 99%

On electrophoresis of a pH‐regulated nanogel with ion partitioning effects

2018

View full text Add to dashboard Cite

The electrophoresis of a polyelectrolyte nanoparticle, whose charge condition depends on the salt concentration and pH of the suspended medium as well as the dielectric permittivity difference, is analyzed. The present nonlinear model for the electrophoresis of this pH-regulated polyelectrolyte (PE) particle is based on the consideration of full set of governing equations of fluid and ion transport coupled with the equation for electric field. The Born energy of the ions are incorporated to account for the difference in the dielectric permittivity of the PE and the electrolyte. The governing equations are computed numerically through a control volume approach. The nonlinear effects are highlighted by comparing with the existing linear model as well as results based on the first-order perturbation analysis valid for a weak applied field. The ion partitioning effect arising due to the difference in self energy of ions between the two media, have a strong impact on the mobility of the PE. The ion partitioning effect attenuates the penetration of counterions in the PE, which enhances the electric force and hence, results in a larger mobility of the PE. The nonlinear effects due to the double layer polarization and relaxation are intensified due to the ion partitioning effect. The ion partitioning effect influences the association/dissociation of PE functional group by tuning the hydrogen/hydroxide ions. Present study shows that the ion partitioning effect is profound for higher salt concentration and/or higher volume density of PE functional groups.

show abstract

Effect of ion partitioning on the electrostatics of soft particles with a volumetrically charged core

Cited by 45 publications

References 23 publications

Space Electroosmotic Thrusters in Ion Partitioning Soft Nanochannels

Space Electroosmotic Thrusters in Ion Partitioning Soft Nanochannels

Effects of dielectric gradients‐mediated ions partitioning on the electrophoresis of composite soft particles: An analytical theory

On electrophoresis of a pH‐regulated nanogel with ion partitioning effects

Contact Info

Product

Resources

About