Colloidal stability of carbon nanotubes in an aqueous dispersion of phospholipid
Authors Dionysios Douroumis, Dimitrios G Fatouros, Nikolaos Bouropoulos, Kostas Papagelis, Dimitrios Tasis
Published 15 January 2008 Volume 2007:2(4) Pages 761—766
Dionysios Douroumis1, Dimitrios G Fatouros2, Nikolaos Bouropoulos3, Kostas Papagelis3, Dimitrios Tasis3
1Phoqus Pharmaceuticals Limited, Kent, UK; 2School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK; 3Department of Materials Science, University of Patras, Rio Patras, Greece
Abstract: Within the family of nanomaterials, carbon nanotubes (CNTs) have emerged as a new effi cient scaffold for studying molecular interactions at interfaces. Poor dispersability of CNTs in any solvent presents a considerable drawback for the development of novel functional composite structures. Previous studies have demonstrated that the solubility of CNTs can be greatly enhanced by employing appropriate surfactants, some of them being biological molecules. In this work, we study the noncovalent wrapping of lipid chains onto the graphitic surface of single-walled material (SWCNTs) by electron microscopy and Raman spectroscopy. Stable and homogenous aqueous suspensions of SWCNTs in the presence of lipids have been prepared, whereas their electrophoretic mobility was confirmed by ζ-potential measurements. Raman measurements revealed that smaller diameter SWCNTs are preferentially dispersed by lipid molecules in the aqueous supernatant part of the prepared suspension.
Keywords: carbon nanotubes, Raman spectroscopy, liposomes, ζ-potential, drug delivery systems