Schematic of CE instrument

1. Separation of Benzene Derivatives Using Carbon Nanotubes (SWNT) and Surfactant Mixture in Capillary Electrophoresis (CE) Fahim Lodhi1, David Ahlstrom2, and Cevdet Akbay2*1Terry Sanford High School, Fayetteville, North Carolina2Department of Natural Sciences, Fayetteville State University, Fayetteville, NC 28301 Background:Capillary electrophoresis (CE) is a separation technique. It can be used to separate ionic species by their charge. Electrically charged analytes move in a buffer under the influence of voltage. To separate neutral molecules such as naphthalene, surfactants are added to the buffer. Sodium dodecyl sulfate (SDS) is the most commonly used surfactant used in CE. It is an anionic (negatively charged) surfactant that is used in industrial products including engine degreasers, floor cleaners, car wash soaps. Is also being used in household products such as toothpastes, shampoos, shaving foams, some dissolvable aspirins, fiber therapy caplets, and bubble baths for its thickening effect and its ability to create a lather. SDS has a tail of 12 carbon atoms (hydrophobic tail=water-hating part), attached to a sulfate group (hydrophilic head=water-loving part), giving the molecule the ability of being soluble in both organic solvents and water. Car Carbon nanotubes (CNTs) are allotropes of carbon. There are two types of CNTs, single-walled CNTs (SWNTs) and milti-walled CNTs (MWNTs). These cylindrical carbon molecules have novel properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science. They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat. Since they are insoluble in water, surfactants (e.g., SDS) are used to disperse them in water. In this study, mixture of SWNT and SDS was used in CE for separation of a few benzene derivatives. Structure of SWNT Chemical structure of SDS Schematic of CE instrument

2. Separation of four benzene derivatives in CE using SWNT-SDS mixture A mAU toluene 350 300 ethylbenzene B benzene 250 200 naphthalene C mAU 6 150 4 100 2 0 50 -2 0 -4 min 10 2 4 6 8 3.5 4 4.5 5 5.5 6 6.5 7 7.5 min Figure: Electropherogram showing the separation of four benzene derivatives (benzene, toluene, ethylbenzene, and naphthalene) using 2% SDS (weight per volume) and 5 mg SWNT mixture in 20 mM Tris buffer. Inset: A) Representation of SWNT-SDS mixture (SDS is coating the surface of SWNT), B) Fahim Lodhi is preparing solutions, C) CE experiment without benzene derivatives (only SWNT-SDS mixture).