Search results for "Current-voltage curve"

showing 3 items of 3 documents

Calcium binding and ionic conduction in single conical nanopores with polyacid chains: model and experiments.

2012

Calcium binding to fixed charge groups confined over nanoscale regions is relevant to ion equilibrium and transport in the ionic channels of the cell membranes and artificial nanopores. We present an experimental and theoretical description of the dissociation equilibrium and transport in a single conical nanopore functionalized with pH-sensitive carboxylic acid groups and phosphonic acid chains. Different phenomena are simultaneously present in this basic problem of physical and biophysical chemistry: (i) the divalent nature of the phosphonic acid groups fixed to the pore walls and the influence of the pH and calcium on the reversible dissociation equilibrium of these groups; (ii) the asym…

General Physics and AstronomyIonic bondingFunctionalizedDissociation (chemistry)Conical nanoporeNanoscale regionschemistry.chemical_compoundNanoporesI - V curveIonic conductivityGeneral Materials ScienceConical nanoporesPhosphonate groupCalcium concentrationChemistryGeneral EngineeringPH effectsPartition functionsIonic channelsIon equilibriumReversible dissociationChemical physicsFunctional groupsThermodynamicsDesalination membranesIon bindingPorosityDissociationBiophysical chemistryDissociation equilibriaInorganic chemistrychemistry.chemical_elementWater filtrationCalciumIonNernst-Planck equationsApplied potentialsIon bindingCarboxylationPhosphonic acidsComputer SimulationCarboxylateParticle SizeControlled drug releaseCurrent voltage curveIonsBinding SitesFixed charge densityPH sensitiveCarboxylic acidsDesalinationPhosphonic acid groupsPoly acidsElectric ConductivityCarboxylic acid groupsFixed ChargesNanostructuresCell membranesCurrent-voltage curvesModels ChemicalQuantum theoryFISICA APLICADACalciumBiological ion channelsCalcium bindingIonic currentCytologyPore wallStatistical mechanicsAcidsACS nano
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Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.

2012

We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…

NanoporeRe-configurablePHAmino acid chainsEtching timeElectrical signalCarboxylic AcidsGeneral Physics and AstronomyFunctionalizationsElectrolytePore surfaceElectrochemistryFunctionalizedCarboxylic acidOptical imageNanoporesElectric conductivityI - V curveElectrochemistryGeneral Materials ScienceTheoretical modelRectifying behaviorsFundamental conceptsRectifying propertiesSurface propertyGeneral EngineeringHydrogen-Ion ConcentrationCigar-shaped nanoporeCharacterization (materials science)Data processingChemistryNanoporeAmino acidsIon channelTransport simulationIodineLogic functionsNanostructureMaterials scienceLogicSurface PropertiesCharacterizationNanotechnologyTunabilitiesArticleDrug controlled releaseElectrical resistivity and conductivityEtchingTransport processPH-responsiveCurrent voltage curveDiodeChemical proceduresCarboxylic acidsLysineElectric ConductivityModels TheoreticalGeometrical opticsNanostructuresAmphoteric amino acid chainsCurrent-voltage curvesExternal solutionsFISICA APLICADAElectrolyte concentrationACS nano
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Nanopore charge inversion and current-voltage curves in mixtures of asymmetric electrolytes

2018

[EN] We consider the screening of the negative charges (carboxylic acid groups) fixed on the surface of a conical-shaped track-etched nanopore by divalent magnesium (Mg2+) and trivalent lanthanum (La3+). The experimental current (I)-voltage (V) curves and current rectification ratios allow discussing fundamental questions about the overcompensation of spatially-fixed charges by multivalent ions over nanoscale volumes. The effects of charge inversion or reversal on nanopore transport are discussed in mixtures of asymmetric electrolytes (LaCl3 and MgCl2 with KCl). In particular, pore charge inversion is demonstrated for La3+ as well as for mixtures of this trivalent ion at low concentrations …

inorganic chemicalsCharged nanoporeMaterials scienceKineticschemistry.chemical_elementFiltration and Separation02 engineering and technologyElectrolyte010402 general chemistry01 natural sciencesBiochemistryDivalentIonLanthanumGeneral Materials SciencePhysical and Theoretical ChemistryMaterialsAsymmetric electrolyteschemistry.chemical_classificationCharge inversionNanotecnologiaCurrent rectification021001 nanoscience & nanotechnology0104 chemical sciencesNanoporeHysteresisMembranechemistryChemical physicsCurrent-voltage curveFISICA APLICADA0210 nano-technology
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