Regensburg 2010 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 40: Nanoparticles and Composite Materials I
CPP 40.9: Vortrag
Donnerstag, 25. März 2010, 11:45–12:00, H48
Functionalization and Characterization of SWCNTs for Electronics Applications — Engin Karabudak1,2, Claudia Backes3, Frank Hauke3, Andreas Hirsch3, and •Wendel Wohlleben1 — 1BASF SE, Polymer Physics Research, 67056 Ludwigshafen, D — 2Present address: MESA+ Research Institute, University of Twente, NL — 3Department of Chemistry and Pharmacy & ZMP, Universität Erlangen-Nürnberg, 91054 Erlangen, D
We report the application of a novel multiwavelength analytical ultracentrifuge (AUC) to the correlation between hydrodynamic size and absorption in CNT dispersions. The statistical relevance is high due to the evaluation of 1011 colloids in one experiment. The machine operates at up to 60 krpm and records c(r,t,lambda) with a 100-fold speed improvement over commercial AUCs. Single-wall CNTs are notoriously difficult to disperse, not only because of their high tendency to agglomerate, but also due to insufficient understanding of the CNT-ligand interactions. Here we prepare an up to 88 percent efficient dispersion of SWCNTs (HiPco and CoMoCAT) by non-covalent ligands (perylene bisimides with Newkome dendrimers) and intercalant agents (perylenes). Without previous purification we quantify from a single 1h-experiment the coexistence of debundled, ligand-encapsulated CNTs; CNT bundles with few ligands attached; hydrolyzed intercalant; intercalant - ligand micelles, with the absorption profiles and anhydrous specific volume for each component. Bulky dendritic groups on the surfactants systematically reduce the adsorption density on the CNT surface, which is on the order of 1 mmol surfactant / g SWCNT.