Papers by Keyword: Non-Covalent Functionalization

Abstract: Here, we report the bonding mechanism and electronic structure of single-walled carbon nanotube and oxygenated single-walled carbon nanotube functionalized by cellulose chain using first-principles density functional theory. Analysis of the optimized molecular configuration and charge redistribution of the nanohybrid indicates that the cellulose chain binds with the prototype single-walled carbon nanotube and oxygenated single-walled carbon nanotube via physisorption. The cellulose chain adsorption on the single-walled carbon nanotube preserved its electronic structure. On the other hand, the electronic structure of the oxygenated single-walled carbon nanotube and cellulose complex reveals that the electronic states of the cellulose tend to populate in the forbidden gap, thus, lowering the bandgap of the overall complex. The electronic structure of the complex can be considered as the superposition of its constituents in which no significant hybridization of the orbital characters is observable. The findings confirm that cellulose is indeed suitable for the non-covalent functionalization of single-walled carbon nanotubes and provide new insights into the electronic structure of the oxygenated single-walled carbon nanotube/cellulose complex.

Abstract: Potential application of Carbon Nanotubes as a drug delivery system is limited by their hydrophobity and their natural tendency to aggregate in the bundles. Dispersion and solubility of Singlewall Carbon Nanotubes (SWCNT) in Phosphate Buffered Saline (PBS) solution via non covalent and covalent interactions was investigated. Galactosyl-β1-Sphyngosine (glycolipid precursor of cerebrosides, structured with a hydrophobic chain, a hydrophilic head and an amine group between them) was used. Pristine SWCNTs were wrapped with Galactosyl-β1-Sphyngosine (Gal-Sphy), whereas the carboxylic groups of the functionalized CNTs were activated in order to interact with amine groups of Galactosylsphyngosine and render the coating stronger. Samples dispersion was characterized by optical absorption spectroscopy (OAS). The comparison and efficiency of the dispersion stability of the functionalized material in respect to the pristine SWCNTs will be presented. We exploited Raman Spectroscopy to evaluate relative purity of the samples, and the Infrared analysis to characterize the presence of the functional groups on the tubes surface. The morphology of the samples was studied using high resolution transmission electron microscopy (HR-TEM).