title: The charging of micellar nanoparticles in electrospray ionization.
abstract: Charging of nanoparticles through electrospray has scarcely been explored. Spherical nanometer-sized amphiphilic block copolymer nanoparticles with diameters ranging from ∼65 to ∼150 nm were electrosprayed and analysed by charge detection spectrometry. Herein, we explore the charging of these micellar nano-objects by conducting a thorough study in different solvents, including pure water, and upon the addition of "supercharging" agents. The charge (z) of micellar nanoparticles electrosprayed from water solution is compared to the Rayleigh's limiting charge (z(R)) of a charged water droplet of the same dimensions. An average ratio (z/z(R)) of 0.6-0.65 is observed for the micellar macro-ions, supporting the charge residue mechanism, where the number of charges available to the micellar macro-ion is limited by the number of charges on the nanodroplet, which is a function of the surface tension of the solvent. Also we show the possibility of increasing the charging of micellar nanoparticles in the negative mode by adding organic bases (in particular piperidine) to water/methanol solutions.
authors: Université de Lyon, Université Lyon 1, CNRS, UMR 5579, LASIM, Villeurbanne Cedex, France.
authors: Tristan
authors: T
authors: Doussineau
authors: Marion
authors: M
authors: Santacreu
authors: Rodolphe
authors: R
authors: Antoine
authors: Philippe
authors: P
authors: Dugourd
authors: Wenjing
authors: W
authors: Zhang
authors: Isabelle
authors: I
authors: Chaduc
authors: Muriel
authors: M
authors: Lansalot
authors: Franck
authors: F
authors: D'Agosto
authors: Bernadette
authors: B
authors: Charleux