Electroviscous effect on the streaming current in a pH-regulated nanochannel

Yeh, Li‐Hsien; Ma, Yu; Xue, Song; Qian, Shizhi

doi:10.1016/j.elecom.2014.08.018

Cited by 24 publications

(6 citation statements)

References 29 publications

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“…In areas far away from the charged nanoparticles (e.g., dotted line in Figure ), it is assumed that the ionic concentration of each kind retains its volume concentration, c i = C i 0 , i = 1, 2, 3, 4. According to the electroneutral condition, the volume concentration of various ions in the solution is as follows When the pH of the solution changes, the biomimetic polyelectrolyte groups’, P ∼ COOH and P ∼ NH 2 , protonation/deprotonation reactions will occur inside the brush layer Assuming the equilibrium constants of the two reactions are K a and K b , respectively where [H + ] is the local concentration of H + in the brush layer, [H + ] = 10 –pH exp(−ϕ/ϕ 0 ), and ϕ 0 = RT/F denotes the reference thermal potential. [P ∼ COO – ], [P ∼ COOH], [P ∼ NH 2 ], and [P ∼ NH 3 + ] denote the bulk density of each electrolyte group in the brush layer, respectively.…”

Section: Mathematical Modelmentioning

confidence: 99%

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Brush Layer Charge Characteristics of a Biomimetic Polyelectrolyte-Modified Nanoparticle Surface

et al. 2020

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Nanoparticle surface charge regulation technology plays an important role in ion rectification, drug delivery, and cell biology. The biomimetic polyelectrolyte can be combined with nanoparticles by nanomodification technology to form a layer of coating, which is called the brush layer of nanoparticles. In this study, based on the Poisson−Nernst−Planck (PNP) equation system, a theoretical model considering a bionic electrolyte brush layer with charge density regulated by a chemical reaction is constructed. The charge properties of brushed nanoparticles are studied by changing the sizes of nanoparticles, the pH value of the solution, background salt solution concentration, and brush layer thickness. The result shows that the charge density of brushed nanoparticles increases with the increase of particle size. The isoelectric point (IEP) of the equilibrium reaction against the brush layer is pH = 5.5. When the pH < 5.5, the charge density of the particle brush layers decreases with the increase of pH, and when the pH > 5.5, the charge density of the particle brush layer increases with the increase of pH. By comparing the charge density of different brush thicknesses, it is found that the larger the brush thickness, the smaller the charge density of the brush layer. This research provides theoretical support for the change of the through pore velocity when macromolecular organic compounds pass through nanopores.

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Section: Mathematical Modelmentioning

confidence: 99%

“…In areas far away from the charged nanoparticles (e.g., dotted line in Figure 1), it is assumed that the ionic concentration of each kind retains its volume concentration, c i = C i0 , i = 1, 2, 3, 4. According to the electroneutral condition, the volume concentration of various ions in the solution is as follows 41 C C 10 and 10…”

Section: ■ Introductionmentioning

confidence: 99%

Brush Layer Charge Characteristics of a Biomimetic Polyelectrolyte-Modified Nanoparticle Surface

et al. 2020

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“…At T = 298 K, the ionic diffusivities of H + (D 1 ), OH À (D 2 ), Cl À (D 3 ), and K + (D 4 ) are fixed at 9.31, 5.30, 2.03, and 1.96 (Â10 À9 m 2 s À1 ), respectively. 59…”

Section: Resultsmentioning

confidence: 99%

Gate modulation of proton transport in a nanopore

Mei

Yeh

Qian

2016

Phys. Chem. Chem. Phys.

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Proton transport in confined spaces plays a crucial role in many biological processes as well as in modern technological applications, such as fuel cells. To achieve active control of proton conductance, we investigate for the first time the gate modulation of proton transport in a pH-regulated nanopore by a multi-ion model. The model takes into account surface protonation/deprotonation reactions, surface curvature, electroosmotic flow, Stern layer, and electric double layer overlap. The proposed model is validated by good agreement with the existing experimental data on nanopore conductance with and without a gate voltage. The results show that the modulation of proton transport in a nanopore depends on the concentration of the background salt and solution pH. Without background salt, the gated nanopore exhibits an interesting ambipolar conductance behavior when pH is close to the isoelectric point of the dielectric pore material, and the net ionic and proton conductance can be actively regulated with a gate voltage as low as 1 V. The higher the background salt concentration, the lower is the performance of the gate control on the proton transport.

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“…These authors found that the (primary) electroviscous effect increases with the increase of ζ-potential. It is worthy to note that neglecting secondary electroviscous effect due to the overlapping of EDL from different particles when it exists, gives place to mistakes as high as 30% in the estimation of streaming conductance in microchannels [37]. Consequently, differences between experimental data and theoretical results are higher when the ionic concentration in the liquid phase is smaller because, in this case, the EDL thickness is larger and the consequences of the overlapping of different EDLs are more dramatic.…”

Section: Electroviscous Effectsmentioning

confidence: 99%

Electroviscous Effects in Stationary Solid Phase Suspensions

Rubio-Hernández

2021

Fluids

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Flowing through porous media is a matter of interest in different research fields such as medicine, engineering and science. The spontaneous appearance of ionic distribution at the solid liquid interface gives place to a reduction in the flow rate, which is generally named electroviscous effect. However, this should be differentiated in two more specific effects, the primary effect due to the distortion of ionic clouds, and the secondary effect due to the overlapping of ionic clouds. Theoretical and experimental works have not always been clearly conducted in order to separate both effects. Instead, they have been globally grouped. The purpose of this review is to revise theoretical and experimental bibliography on the electroviscous effect in stationary solid phase suspensions (porous plugs, membranes, microchannels, capillaries). The main conclusions of this brief revision are: (i) when ionic clouds are relatively small, it is possible to accept that only the primary effect is the cause for the apparent increase of the viscosity of the liquid phase when it is forced to flow relative to the stationary solid phase; (ii) although theory predicts a maximum for the variation of the overall electroviscous effect vs the relative size of the ionic cloud, it has been experimentally observed but not properly reasoned that its existence depends on the salt type; and (iii) it is necessary to justify why, if the fluid is non-Newtonian, electrokinetic parameters dominate the characteristics of the flow due to high pressure gradients, but the rheological parameters are more decisive when the flow is generated by low pressure gradients.

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Electroviscous effect on the streaming current in a pH-regulated nanochannel

Cited by 24 publications

References 29 publications

Brush Layer Charge Characteristics of a Biomimetic Polyelectrolyte-Modified Nanoparticle Surface

Brush Layer Charge Characteristics of a Biomimetic Polyelectrolyte-Modified Nanoparticle Surface

Gate modulation of proton transport in a nanopore

Electroviscous Effects in Stationary Solid Phase Suspensions

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