title: Scaling Behavior for Ionic Transport and its Fluctuations in Individual Carbon Nanotubes.
abstract: In this Letter, we perform an experimental study of ionic transport and current fluctuations inside individual carbon nanotubes (CNTs). The conductance exhibits a power law behavior at low salinity, with an exponent close to 1/3 versus the salt concentration in this regime. This behavior is rationalized in terms of a salinity dependent surface charge, which is accounted for on the basis of a model for hydroxide adsorption at the (hydrophobic) carbon surface. This is in contrast to boron nitride nanotubes which exhibit a constant surface conductance. Further, we measure the low frequency noise of the ionic current in CNTs and show that the amplitude of the noise scales with the surface charge, with data collapsing on a master curve for the various studied CNTs at a given pH.
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550, 24 Rue Lhomond 75005 Paris, France.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Secchi
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550, 24 Rue Lhomond 75005 Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Niguès
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550, 24 Rue Lhomond 75005 Paris, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Jubin
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550, 24 Rue Lhomond 75005 Paris, France.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Siria
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550, 24 Rue Lhomond 75005 Paris, France.
authors.forename: Lydéric
authors.initials: L
authors.lastname: Bocquet