title: Size characterization of the associations between carbon nanotubes and humic acids in aqueous media by asymmetrical flow field-flow fractionation combined with multi-angle light scattering.
abstract: This work focuses on the influence of humic acids (HAs) on the fate of carbon nanotubes (CNTs) in aqueous media. This influence was demonstrated by mixing CNT powder with HAs in aqueous solution in varying concentrations. The aqueous media containing HAs and CNTs were size-characterized by asymmetrical flow field-flow fractionation (AsFlFFF) coupled with multi-angle light scattering (MALS). This coupling yielded information concerning the size distribution of single- and multi-walled CNTs (SWCNTs and MWCNTs) and HAs under different physico-chemical conditions that can occur in environmental water. HAs can disperse individual CNTs in aqueous media. However, the difference in the physical structure between SWCNTs and MWCNTs leads to significant differences in the quantity of HA that can adsorb onto the nanotube surface and in the stability of the CNT/HA complex. Compared with MWCNTs, SWCNTs suspended in HAs are less affected by changing ionic strength with respect to stability and the amount suspended.
authors.affiliation: Université de Pau et des Pays de l'Adour, IPREM (UPPA)/CNRS, Technopôle Hélioparc, Av. du Président Angot, 64053 Pau Cedex, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Gigault
authors.forename: Bruno
authors.initials: B
authors.lastname: Grassl
authors.forename: Gaëtane
authors.initials: G
authors.lastname: Lespes
mesh_terms: D006812:Humic Substances / Q000032:analysis*; D008027:Light; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009994:Osmolar Concentration; D010316:Particle Size; D012542:Scattering, Radiation; D014867:Water / Q000737:chemistry*
chemical_list: D006812:Humic Substances; D037742:Nanotubes, Carbon; D014867:Water