Spectroscopic evidence for pi-pi interaction between poly(diallyl dimethylammonium) chloride and multiwalled carbon
De-Quan Yang1, Jean-Francois Rochette, Edward Sacher
1Regroupement Québécois de Matériaux de Pointe, Département de Génie Physique, Ecole Polytechnique, C.P. 6079, Succursale Centre-Ville, Montréal, Québec, H3C 3A7, Canada.
Abstract:
The interaction between multiwalled carbon nanotubes (MWCNTs) and aqueous poly(diallyl dimethylammonium) chloride (PDDA) was studied by X-ray photoelectron (XPS) and photoacoustic Fourier transform infrared (PA-FTIR) spectroscopies. We have found that the mild sonication of MWCNTs in aqueous PDDA results in a significant improvement of CNT dispersibility and greatly enhances their adhesion to Au and Si substrates. The MWCNT-PDDA interaction is due to the presence of an unsaturated contaminant in the PDDA chain, as confirmed by both XPS and PA-FTIR, which enters into a pi-pi interaction with the CNTs. Electrostatic group repulsions of the coated CNTs then provide the dispersibility and adhesion.
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