title: Controlling the electrophoretic mobility of single-walled carbon nanotubes: a comparison of theory and experiment.
abstract: The electrophoretic mobilities of single-walled carbon nanotubes (SWNTs) in agarose gels subjected to negatively charged covalent functionalization and noncovalent anionic surfactant adsorption are compared using a simplified hydrodynamic model. Net charges are calculated on the basis of estimated friction coefficients for cylindrical rodlike particles. The effects of functionalization with negatively charged 4-hydroxybenzene diazonium and anionic sodium cholate are quantified and compared with model predictions. The adsorption of Na+ counterions into the nonionic surfactant layer adsorbed on SWNTs (Triton-X-405) is shown to induce a positive charge and reverse the mobility under select conditions. This effect has not been identified or quantified for nanoparticle systems and may be important in the processing of these systems.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Monica L
authors.initials: ML
authors.lastname: Usrey
authors.forename: Nitish
authors.initials: N
authors.lastname: Nair
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Agnew
authors.forename: Cesar F
authors.initials: CF
authors.lastname: Pina
authors.forename: Michael S
authors.initials: MS
authors.lastname: Strano
mesh_terms: D000327:Adsorption; D000465:Algorithms; D000838:Anions; D002412:Cations; D003979:Diazonium Compounds / Q000737:chemistry; D004587:Electrophoresis, Agar Gel; D008163:Luminescent Measurements; D008962:Models, Theoretical; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D012212:Rheology; D012964:Sodium / Q000737:chemistry; D020358:Sodium Cholate / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: C519251:4-hydroxybenzene diazonium; D000838:Anions; D002412:Cations; D003979:Diazonium Compounds; D037742:Nanotubes, Carbon; D010636:Phenols; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D012964:Sodium; D020358:Sodium Cholate