Intrinsic Ion Selectivity of Narrow Hydrophobic Pores

Song, Chen; Corry, Ben

doi:10.1021/jp810102u

Cited by 187 publications

(210 citation statements)

References 54 publications

Supporting

Mentioning

190

Contrasting

Order By: Relevance

“…As these results are average interaction energies, they do not include entropic contributions and thus cannot be directly compared to the free energy barriers (free energy barriers include both enthalpic and entropic contributions), however, they do support that dehydration is the major cause of the free energy barriers. Further, a comparison with partial dehydration energies for chloride previously reported 43 shows a similar trend and magnitude to the results obtained here, again supporting the claim that the obtained energy barriers are due to partial dehydration.…”

supporting

confidence: 90%

Quantifying barriers to monovalent anion transport in narrow non-polar pores

Richards

Schäfer

Richards

et al. 2012

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

The transport of anionic drinking water contaminants (fluoride, chloride, nitrate and nitrite) through narrow pores ranging in effective radius from 2.5 to 6.5 Å was systematically evaluated using molecular dynamics simulations to elucidate the magnitude and origin of energetic barriers encountered in nanofiltration. Free energy profiles for ion transport through the pores show that energy barriers depend on pore size and ion properties and that there are three key regimes that affect transport. The first is where the ion can fit in the pore with its full inner hydration shell, the second is where the pore size is between the bare ion and hydrated radius, and the third is where the ion size approaches that of the pore. Energy barriers in the first regime are relatively small and due to rearrangement of the inner hydration shell and/or displacement of further hydration shells. Energy barriers in the second regime are due to partial dehydration and are larger than barriers seen in the first regime. In the third regime, the pore becomes too small for bare ions to fit regardless of hydration and thus energy barriers are very high. In the second regime where partial dehydration controls transport, the trend in the slopes of the change in energy barrier with pore size corresponds to the hydration strength of the anions.

show abstract

supporting

confidence: 90%

Quantifying barriers to monovalent anion transport in narrow non-polar pores

Richards

Schäfer

Richards

et al. 2012

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…From this finding, they suggested an existence of a free energy barrier for the pore partitioning that could be adjusted via tailoring of pore charge density as shown in Table 4.1. (Song and Corry 2009) demonstrated pressure controlled ion selectivity in narrow CNTs. For this purpose, they examined SWNTs with diameters of 3.4-6.1 Å to reveal that Na + , K + and Cl -ions face different energy barriers in entering the pore mouth of CNT.…”

Section: Ion Selectivitymentioning

confidence: 99%

Carbon Nanotube Nanofluidics

Choi¹,

Alexandrová²,

Park

2011

Carbon Nanotubes Applications on Electron Devices

View full text Add to dashboard Cite

“…Moreover, their single atom thickness makes these systems ideal for interrogating ion dehydration [29,30], which both sheds light on recent experiments on ion selectivity in porous graphene [25,26,28] and will help analyze the behavior of biological pores [29,30]. Dehydration has been predicted to give rise to ion selectivity and quantized conductance in long, narrow pores [31][32][33][34][35] but the energy barriers are typically so large that the currents are minuscule, which is rectified by the use of membranes with single-atom thickness [29,30].…”

mentioning

confidence: 99%

Maxwell-Hall access resistance in graphene nanopores

Sahu

Zwolak

2018

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The resistance due to the convergence from bulk to a constriction, for example, a nanopore, is a mainstay of transport phenomena. In classical electrical conduction, Maxwell, and later Hall for ionic conduction, predicted this access or convergence resistance to be independent of the bulk dimensions and inversely dependent on the pore radius, a, for a perfectly circular pore. More generally, though, this resistance is contextual, it depends on the presence of functional groups/charges and fluctuations, as well as the (effective) constriction geometry/dimensions. Addressing the context generically requires all-atom simulations, but this demands enormous resources due to the algebraically decaying nature of convergence. We develop a finite-size scaling analysis, reminiscent of the treatment of critical phenomena, that makes the convergence resistance accessible in such simulations. This analysis suggests that there is a "golden aspect ratio" for the simulation cell that yields the infinite system result with a finite system. We employ this approach to resolve the experimental and theoretical discrepancies in the radius-dependence of graphene nanopore resistance.Ion transport through pores and channels plays an important role in physiological functions [1][2][3] and in nanotechnology, with applications such as DNA sequencing [4][5][6], imaging living cells [7][8][9], filtration [10], and desalination [11], among others. These pores localize the flow of ions and molecules across a membrane, where sensors, for example, nanoscale electrodes for DNA sequencing [12][13][14][15][16][17][18] , can interrogate the flowing species as they pass through and where functional elements can selectivity regulate the movement of different species (for example, ion types).In particular, from DNA sequencing [19][20][21][22] to filtration [23][24][25][26][27], graphene nanopores and porous membranes are one of the most promising materials for applications. Novel fabrication strategies and designs are under development to create large-scale, controllable porous membranes [25,26,28] and graphene laminate devices [23,24]. Moreover, their single atom thickness makes these systems ideal for interrogating ion dehydration [29,30], which both sheds light on recent experiments on ion selectivity in porous graphene [25,26,28] and will help analyze the behavior of biological pores [29,30]. Dehydration has been predicted to give rise to ion selectivity and quantized conductance in long, narrow pores [31][32][33][34][35] but the energy barriers are typically so large that the currents are minuscule, which is rectified by the use of membranes with single-atom thickness [29,30].Despite the intense and broad interest in ion transport, one of its most fundamental aspects, the convergence of the bulk to the pore, is essentially not computable with all-atom molecular dynamics (MD) [36], yet is very important for understanding in vivo operation and characteristics of ion channels [37]. Experiments on mono-or bi-layer graphene, show a dominant 1/a access ...

show abstract

Intrinsic Ion Selectivity of Narrow Hydrophobic Pores

Cited by 187 publications

References 54 publications

Quantifying barriers to monovalent anion transport in narrow non-polar pores

Quantifying barriers to monovalent anion transport in narrow non-polar pores

Carbon Nanotube Nanofluidics

Maxwell-Hall access resistance in graphene nanopores

Contact Info

Product

Resources

About