Rectified Ion Transport through Concentration Gradient in Homogeneous Silica Nanochannels

Cheng, Li-Jing; Guo, Likun

doi:10.1021/nl071770c

Cited by 217 publications

(247 citation statements)

References 16 publications

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“…The theoretical framework provided in this work for a 3D and 3-layers systems can be expanded upon to account for additional effects, e.g. asymmetric bulk concentrations [21,22], non-straight nanochannel/nanopore geometries [32], or even asymmetric entrances of a straight permselective medium [14]. …”

Section: Discussionmentioning

confidence: 99%

“…Although, electro-convection effects may enhance current rectification, these usually become significant only at sufficiently high voltages when the SCL appears. Other previously studied symmetry breaking conditions that rectify current include asymmetric concentrations in opposing reservoirs [21], modulation of the nanochannel surface charge [22], non-straight (commonly conical or funnel-shaped) nanochannel/nanopore geometry [23,24].…”

Section: Imentioning

confidence: 99%

“…Such a geometry realistically describes systems that have been the subject of numerous recent experimental and numerical works [6,11,12,15,21,[27][28][29][30][31][32][34][35][36][37]41,42]. Additionally, this geometry can also describe a periodic array of permselective regions (e.g.…”

Section: B Geometry and Boundary Conditionsmentioning

confidence: 99%

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Effect of geometry on concentration polarization in realistic heterogeneous permselective systems

2014

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This study extends previous analytical solutions of concentration-polarization occurring solely in the depleted region, to the more realistic geometry consisting of a three dimensional (3D) heterogeneous ion-permselective medium connecting two opposite microchambers (i.e. 3 layers system). Under the local electro-neutrality approximation, the separation of variable methods is used to derive an analytical solution of the electro-diffusive problem for the two opposing asymmetric microchambers. Assuming an ideal permselective medium allows for the analytic calculation of the 3D concentration and electric potential distributions as well as a current-voltage relation. It is shown that any asymmetry in the microchamber geometries will result in current rectification. Moreover, it is demonstrated that for non-negligible microchamber resistances the conductance does not exhibit the expected saturation at low concentrations but instead shows a continuous decrease. The results are intended to facilitate a more direct comparison between theory and experiments as now the voltage drop is across a realistic 3D and 3-layer system.

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Section: Discussionmentioning

confidence: 99%

Section: Imentioning

confidence: 99%

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Effect of geometry on concentration polarization in realistic heterogeneous permselective systems

2014

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“…Lauga et al, 2006;Seth et al, 2007͒. We believe that further knowledge of liquid slip is important for nanofluidics because of the potential to design systems with enhanced fluid transport ͑Cheng and Giordano, 2002;Eijkel, 2007͒. ͑d͒ Application to nanochannels. The space-charge model has been simplified by Pennathur and Santiago ͑2005a͒ to describe electrokinetic transport in long nanochannels, confirmed by their experimental studies ͑Pennathur and Santiago, 2005b͒.…”

Section: Comprehensive Electrokinetic Theory For Nanochannelsmentioning

confidence: 99%

“…In a single step with elevated temperature and pressure, a channel template can be imprinted onto a thin polymer film cast on a glass cover slip ͑Quake and Scherer, 2000; Guo et al, 2003;Cheng and Guo, 2004͒ …”

Section: Nanoimprint Lithographymentioning

confidence: 99%

Transport phenomena in nanofluidics

2008

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The transport of fluid in and around nanometer-sized objects with at least one characteristic dimension below 100 nm enables the occurrence of phenomena that are impossible at bigger length scales. This research field was only recently termed nanofluidics, but it has deep roots in science and technology. Nanofluidics has experienced considerable growth in recent years, as is confirmed by significant scientific and practical achievements. This review focuses on the physical properties and operational mechanisms of the most common structures, such as nanometer-sized openings and nanowires in solution on a chip. Since the surface-to-volume ratio increases with miniaturization, this ratio is high in nanochannels, resulting in surface-charge-governed transport, which allows ion separation and is described by a comprehensive electrokinetic theory. The charge selectivity is most pronounced if the Debye screening length is comparable to the smallest dimension of the nanochannel cross section, leading to a predominantly counterion containing nanometer-sized aperture. These unique properties contribute to the charge-based partitioning of biomolecules at the microchannel-nanochannel interface. Additionally, at this free-energy barrier, size-based partitioning can be achieved when biomolecules and nanoconstrictions have similar dimensions. Furthermore, nanopores and nanowires are rooted in interesting physical concepts, and since these structures demonstrate sensitive, label-free, and real-time electrical detection of biomolecules, the technologies hold great promise for the life sciences. The purpose of this review is to describe physical mechanisms on the nanometer scale where new phenomena occur, in order to exploit these unique properties and realize integrated sample preparation and analysis systems.

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