A universal ultracentrifuge spectrometer visualizes CNT-intercalant-surfactant complexes.

Interacting solutes form mUltiple associates and usually mask each other in ensemble characterization. They are susceptible to preparation artefacts in the single-molecule techniques commonly applied. To overcome the problem of bulk characterization of a single-walled carbon nanotube (CNT) dispersion with a novel surfactant-intercalant mixture, we obtain color movies of fractionation under extreme gravity, such that each colloidal component is characterized independently. We combine the unique fractionation power of ultracentrifugationl!) with full absorption spectra etA) at each radial position r at each time step t during the sedimentation process.[2,3) In ref. [8], ligand attachment CNTs was studied with the Beckman model XLA centrifuge, which tracks only e(r,t) at a single wavelength, requiring extended modeling for analysis. Our spectrometer/CCD opticsI2.3) adds a third dimension and generates wavelength-resolved movies of the centrifuge fractionation e(r,t,},). This allows independent ligand and CNT tracking without hydrodynamic modeling. We identify the interactions in unpurified intercalant-surfactant-CNT dispersions and obtain the unexpected proof of four coexisting heteroassociates by a novel model-free evaluation. Solubilization of carbon nanotubes is of primary importance to increase the processability of this unique class of materials. Despite the progress in separating and sorting SWCNTs by electrophoresis, density gradient ultracentrifugation or chromatography, CNT-based technology has not yet been realized on a commercial scale, as the CNT separation is limited to individualized nanotubes.14,S) It has previously been shown that designed water-soluble perylene bisimide derivatives such as 1 are excellent CNT surfactants, yielding CNT dispersions with up to 73 % of the CNTs stably dispersed and containing 60% of in-