Molecular simulations of electroosmotic flows in rough nanochannels

Liu, Jin; Wang, Moran; Chen, Shiyi; Robbins, Mark O.

doi:10.1016/j.jcp.2010.06.042

Cited by 32 publications

(21 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10 Liu et al also reported that the electro-osmotic drag depends on the channel size and also channel roughness. 11 In such a structure, Kobayashi 12 reported that S-PEEK can have high proton-conductivity of 10 À4 -10 À2 S=cm at room temperature. Zaidi and his co-workers have observed an enhancement of proton conductivity from the composite membrane consisting of S-PEEK and solid heteropolyacids.…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature on structure and water transport of hydrated sulfonated poly(ether ether ketone): A molecular dynamics simulation approach

Brunello

Mateker

Lee

et al. 2011

Journal of Renewable and Sustainable Energy

View full text Add to dashboard Cite

The effects of temperature on hydrated sulfonated poly(ether ether ketone) are studied using molecular dynamics. Three different temperature conditions (298 K.15 K, 323.15 K, and 353.15 K) with two different water contents (10 wt. % and 20 wt. %) are simulated. Analyzing the pair correlation functions, it is found that there is limited temperature effect on the distribution and solvation of the sulfonate groups. The structure factor analysis shows that the temperature dependence of the nanophase-segregated morphology is not significant in the simulated temperature range. On the contrary, the structure factors S q ð Þ at $30 Å (q ¼ $0.2 Å À1 ) and $13 Å (q ¼ $0.5 Å À1 ) clearly increase with water content, indicating that the development of water channels is mostly affected by the water content. Within such water phase in the nanophase-segregated structure, the internal structure of water phase becomes more developed with decreasing temperature and increasing water content. By analyzing the mean square displacement of the water molecules, it is also found that self-diffusion of water is enhanced with the increasing temperature. From the observation that the activation energies calculated from such temperature dependency are very similar (E a ¼ 25.7 kJ=mol and E a ¼ 24.9 kJ=mol for 10 wt. % and 20 wt. %, respectively), it is inferred that the extent of the structural change in the water phase as a function of temperature is very similar between the 10 wt. % water content and the 20 wt. % water content. Compared to the bulk water (13.2 kJ=mol) and the water in Nafion (16.7-18.9 kJ=mol), it is confirmed that more nanophase-segregation enhances water transport through the membrane.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of temperature on structure and water transport of hydrated sulfonated poly(ether ether ketone): A molecular dynamics simulation approach

Brunello

Mateker

Lee

et al. 2011

Journal of Renewable and Sustainable Energy

View full text Add to dashboard Cite

show abstract

“…[9][10][11] These analyses usually focus on periodic roughness and are invariably limited to 2D. 12,13,15,16 In one study, Valdes et al 14 used pyramidal shapes in a 3-dimensional domain that were randomly placed throughout the channel surface in accordance to data acquired from an actual surface. However, the CFD surface did not mimic the actual surface exactly.…”

mentioning

confidence: 99%

“…As a result, the true effect of a tangible surface was not investigated. Recently, Liu et al 12 analyzed three-dimensional surface roughness using molecular dynamics in nanochannels with c ¼ 3% and found that random roughness had a greater effect on flow than periodic obstructions. While molecular dynamics simulations are exceedingly useful in gaining insight into the mechanics involved, they are limited to very small domains and time-scales due to their prohibitive computational cost.…”

mentioning

confidence: 99%

Nanoscale surface roughness affects low Reynolds number flow: Experiments and modeling

Jaeger

Ren

Xie

et al. 2012

Applied Physics Letters

View full text Add to dashboard Cite

Most micro-channel fabrication strategies generate nano-to-micro-scale, stochastic surface roughness. This inherent stochasticity can potentially be harnessed to direct microfluidic operations such as self-cleaning behavior and localized mixing. This work investigates the effect of stochastic nanoscale roughness on low to moderate Reynolds number Newtonian flow using concurrent modeling and experiments. We fabricate a microscopic channel with tailored hydrofluoric-acid-etched rough surfaces. Optical profilometry and micro-particle-image-velocimetry (micro-PIV) are used to characterize the surface roughness and flow field and is integrated with direct numerical simulation that resolves effects of nanoscale roughness. Results indicate that nanoscale roughness causes flow perturbations that extend up to the mid-plane and is insensitive to flow-rates.

show abstract

“…The PPPM (Particle-particle-particle mesh) scheme [29][30][31] is used to calculate the long-range Coulomb force with a precision of 10 4 , and the slab boundary 32 is used for the non-periodic direction (z direction in Figure 1). We set r COUL ,c = r LJ ,c for a best calculation performance.…”

Section: Interaction Functionsmentioning

confidence: 99%

Molecular dynamics for ion-tuned wettability in oil/brine/rock systems

Tian

Wang

2017

AIP Advances

Self Cite

View full text Add to dashboard Cite

The dependence of wettability on brine ionic composition in oil/brine/rock systems, which is denoted as ion-tuned wettability, has important applications in geoscience. Due to the involvement of non-continuum effects, molecular dynamics (MD) simulation is necessary to improve understanding of its mechanism. This work establishes a reliable molecular dynamics (MD) framework to study ion-tuned wettability. We prove that our model system can well represent the wettability of the real oil/brine/rock system, and that the wettability alteration from the MD results is qualitatively consistent with the EDL repulsion theory when ion-binding does not exist. In the process to establish the MD framework, our work suggests that adding counter ions to balance interface charges is good for studying concentration effect on wettability, and the contact angle defined from mass center coordinates is effective to measure the wettability of the nano-scale MD system. This work provides the basis for on-going studies using MD simulation to reveal the mechanism of ion-tuned wettability.

show abstract

Molecular simulations of electroosmotic flows in rough nanochannels

Cited by 32 publications

References 44 publications

Effect of temperature on structure and water transport of hydrated sulfonated poly(ether ether ketone): A molecular dynamics simulation approach

Effect of temperature on structure and water transport of hydrated sulfonated poly(ether ether ketone): A molecular dynamics simulation approach

Nanoscale surface roughness affects low Reynolds number flow: Experiments and modeling

Molecular dynamics for ion-tuned wettability in oil/brine/rock systems

Contact Info

Product

Resources

About