Determination of the surface coverage of exfoliated carbon nanotubes by surfactant molecules in aqueous solution.
To determine the surface coverage of exfoliated carbon nanotubes by surfactant molecules, we propose four experimental methods based on thermogravimetric analysis, UV-vis spectroscopy, surface tension measurements, and a variant of Maron's titration. We apply all four methods to aqueous mixtures of carbon nanotubes and the surfactant sodium dodecyl sulfate and consistently find a surface coverage of between 1.5 and 2 g of surfactant per gram of carbon nanotubes. This corresponds to slightly more than two SDS molecules per square nanometer, which is comparable to the known maximum packing density of SDS at the air-water interface.
Grossiord
Nadia
N
Laboratory of Polymer Chemistry, Polymer Physics Group, and Process Development Group, Technical University of Eindhoven, Postbus 513, 5600 MB Eindhoven, The Netherlands.
Schoot
Paul van der
Pv
Meuldijk
Jan
J
Koning
Cor E
CE