Theory of membrane equilibria and membrane potentials in the presence of non-dialysing electrolytes. A contribution to physical-chemical physiology

Donnan, F. G.

doi:10.1016/0376-7388(94)00297-c

Cited by 428 publications

(237 citation statements)

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“…The PMIA NF membrane displays higher rejections to salts containing divalent anions with a higher co-ion charge, and lower rejections to salts containing divalent cations with a higher counter-ion charge. This observation is consistent with the exclusion mechanism, as reported by Donnan [43]. That is, the sulfonic acid groups on the membrane surface exert a stronger electrostatic repulsion effect on SO 2 À 4 than on Cl À .…”

Section: Water Flux and Charge Characterization Of Pmia Nf Hollow Fibsupporting

confidence: 91%

Fabrication of novel poly(m-phenylene isophthalamide) hollow fiber nanofiltration membrane for effective removal of trace amount perfluorooctane sulfonate from water

Wang

Zhao

et al. 2015

Journal of Membrane Science

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a b s t r a c tThis study investigated the separation performance of a hollow fiber nanofiltration membrane, which was fabricated from poly(m-phenylene isophthalamide) (PMIA) using a dry-jet wet spinning technology, for sustainable water recovery from water containing trace amount of perfluorooctane sulfonate (PFOS) that was a persistent organic pollutant commonly existed in water. SEM spectra indicated that the cross section of the hollow fiber membrane had an asymmetrical structure that consisted of a dense outer surface acting as a selectively layer, a spongy-like transition layer, and finger-like microvoids close to the inner surface. The average pore size and molecular weight cut-off, which were estimated using the solute rejection method, were 0.404 nm and 904 Da, respectively. The PFOS rejection experiments were carried out at the trans-membrane pressures ranging from 4 Â 10 5 Pa to 1.0 Â 10 6 Pa and PFOS concentrations from 50 μg/L to 500 μg/L. In all cases, the PFOS rejections were found to be increased as the PFOS concentration increased. The impact of the pH value and Ca 2 þ concentration of the feed solution on the PFOS rejections was studied in detail. The PFOS rejections improved from 91.17% to 97.49% with an increase in pH from 3.2 to 9.5 at 4 Â 10 5 Pa. An increase of Ca 2 þ concentration from 0.1 mM to 2 mM enhanced PFOS rejection from 97.10% to 99.40% at a trans-membrane pressure of 4 Â 10 5 Pa. The sorption/desorption experiments indicated that the amount of PFOS adsorbed on the membrane surface was five times higher in the presence of Ca 2 þ (2 mM). AFM experiments also demonstrated that the membrane surface was rough with the addition of Ca 2 þ . Hence, the presence of Ca 2 þ enhanced the PFOS adsorption in the membrane surface and caused more pore blockage of the membrane. As such, the declination in the water flux and augmentation in the PFOS rejection were observed.

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Section: Water Flux and Charge Characterization Of Pmia Nf Hollow Fibsupporting

confidence: 91%

Fabrication of novel poly(m-phenylene isophthalamide) hollow fiber nanofiltration membrane for effective removal of trace amount perfluorooctane sulfonate from water

Wang

Zhao

et al. 2015

Journal of Membrane Science

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“…To understand the relative importance of these rejection mechanisms, we investigate ion exclusion and selectivity as a function of solution concentration, pH, ion valence, and ion size. Our measurements provide a strong indication that ion rejection in nanopores of this size is mostly governed by the electrostatic effects and demonstrate that Donnan's membrane equilibrium model (29,30) accounts for most of the experimentally observed transport selectivities. Although it is not clear whether continuum models can be rigorously applied at the sub-2-nm scale relevant for this study, they provide an insight into the nature of the ion transport process.…”

mentioning

confidence: 57%

Ion exclusion by sub-2-nm carbon nanotube pores

Fornasiero¹,

Park

Holt³

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

643

550

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Biological pores regulate the cellular traffic of a large variety of solutes, often with high selectivity and fast flow rates. These pores share several common structural features: the inner surface of the pore is frequently lined with hydrophobic residues, and the selectivity filter regions often contain charged functional groups. Hydrophobic, narrow-diameter carbon nanotubes can provide a simplified model of membrane channels by reproducing these critical features in a simpler and more robust platform. Previous studies demonstrated that carbon nanotube pores can support a water flux comparable to natural aquaporin channels. Here, we investigate ion transport through these pores using a sub-2-nm, aligned carbon nanotube membrane nanofluidic platform. To mimic the charged groups at the selectivity region, we introduce negatively charged groups at the opening of the carbon nanotubes by plasma treatment. Pressure-driven filtration experiments, coupled with capillary electrophoresis analysis of the permeate and feed, are used to quantify ion exclusion in these membranes as a function of solution ionic strength, pH, and ion valence. We show that carbon nanotube membranes exhibit significant ion exclusion that can be as high as 98% under certain conditions. Our results strongly support a Donnan-type rejection mechanism, dominated by electrostatic interactions between fixed membrane charges and mobile ions, whereas steric and hydrodynamic effects appear to be less important.biomimetic platform ͉ ion channel ͉ ion transport ͉ nanofiltration I on transport across cellular membranes is essential to many of life's processes, such as electrical signaling in nerves, muscles, and synapses or cell's maintenance of homeostatic balance. Biological systems achieve rapid, selective, and ultraefficient transmembrane mass transport by employing a large variety of specialized protein channels of nanometer or subnanometer size (1). High-resolution x-ray structures, protein sequencing, targeted mutations, and biophysical characterizations have provided new insight on the link between nanochannel protein architecture, transport rates, selectivity, and gating properties. Interestingly, these studies have shown that membrane nanochannels share several common features. For example, aquaporins (2, 3), proton channels (4, 5), and ion channels (6-11) all have relatively narrow and hydrophobic pore regions. By contrast, the selectivity filter regions of membrane ion channels are enriched with charged residues.Despite the enormous progress made in recent decades, the complex macromolecular nature of these biological machines still complicates our understanding of the underlying mechanisms responsible for fast mass transport, selectivity, gating, and the functional role of hydrophobic pore lining and charged functionalities. Thus, it is important to create simplified, biomimetic nanochannels that could help to clarify the physics of ion permeation at the nanoscale, as well as create the next generation of membranes that employ efficient molecul...

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“…This is because of the coupling of the IMS with DEE and the abovementioned difficulty of the precipitation agent to penetrate the polymeric matrix as result of electrostatic equilibrium. In this case, IMS is coupled with DEE [15,64,65] predicts that the use of negatively charged precipitation agents as S 2-leads to the precipitation and location of the CdS -QDs mainly on the surface of the supporting matrix.…”

Section: Resultsmentioning

confidence: 99%

Intermatrix Synthesis as a rapid, inexpensive and reproducible methodology for the in situ functionalization of nanostructured surfaces with quantum dots

Bastos-Arrieta

Muñoz

Stenbock-Fermor

et al. 2016

Applied Surface Science

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This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Multiwall Carbon Nanotubes (MWCNTs) and Nanodiamonds (NDs). The synthetic route takes advantage of the ion exchange functionality of the reactive surfaces for the loading of the QDs precursor and consequent QDs appearance by precipitation. The benefits of such modified nanomaterials were studied using CdS-QDs@MWCNTs hybrid-nanomaterials.CdS-QDs@MWCNTs has been used as conducting filler for the preparation of electrochemical nanocomposite sensors, which present electrocatalytic properties. Finally,

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Theory of membrane equilibria and membrane potentials in the presence of non-dialysing electrolytes. A contribution to physical-chemical physiology

Cited by 428 publications

References 0 publications

Fabrication of novel poly(m-phenylene isophthalamide) hollow fiber nanofiltration membrane for effective removal of trace amount perfluorooctane sulfonate from water

Fabrication of novel poly(m-phenylene isophthalamide) hollow fiber nanofiltration membrane for effective removal of trace amount perfluorooctane sulfonate from water

Ion exclusion by sub-2-nm carbon nanotube pores

Intermatrix Synthesis as a rapid, inexpensive and reproducible methodology for the in situ functionalization of nanostructured surfaces with quantum dots

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