Comparative Study of SWNTs Dispersion in Organic Solvent and Surfactant Along with Observation of Multilayer Graphene

Organic solvents and surfactants both are used to disperse Carbon Nanotubes (CNTs), but the efficiency of both are different. Surfactant much efficiently disperse CNTs in comparison to organic solvent. As opposed to aqueous solutions, hydrophobic Single Wall Nanotubes (SWNTs) are easily wetted by organic solvent Di-Methyl Formamide (DMF) and therefore, to reduce self assembling of bundles and ropes of CNTs. Surfactants are effective at concentration 1 wt % for dispersion of SWNTs. Sodium Dodecyl Benzene Sulfonate (SDBS) effectively disperse aqueous solution of SWNTs at 0.5 mg/ml and further solution is diluted to concentration 0.3 mg/ml. Probe type sonication is used to make homogeneous solution and for initial exfoliation of CNTs. Small bundles and single SWNTs can be separated from bundles and amorphous carbon by using centrifugation. Atomic Force Microscopy (AFM) is employed to image the dispersed state of SWNTs by using organic solvent and aqueous solution of surfactant. Graphene presence and density difference of these are also observed at different concentration of SWNTs.