title: Alignment dynamics of single-walled carbon nanotubes in pulsed ultrahigh magnetic fields.
abstract: We have measured the dynamic alignment properties of single-walled carbon nanotube (SWNT) suspensions in pulsed high magnetic fields through linear dichroism spectroscopy. Millisecond-duration pulsed high magnetic fields up to 56 T as well as microsecond-duration pulsed ultrahigh magnetic fields up to 166 T were used. Because of their anisotropic magnetic properties, SWNTs align in an applied magnetic field, and because of their anisotropic optical properties, aligned SWNTs show linear dichroism. The characteristics of their overall alignment depend on several factors, including the viscosity and temperature of the suspending solvent, the degree of anisotropy of nanotube magnetic susceptibilities, the nanotube length distribution, the degree of nanotube bundling, and the strength and duration of the applied magnetic field. To explain our data, we have developed a theoretical model based on the Smoluchowski equation for rigid rods that accurately reproduces the salient features of the experimental data.
authors.affiliation: Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Jonah
authors.initials: J
authors.lastname: Shaver
authors.forename: A Nicholas G
authors.initials: AN
authors.lastname: Parra-Vasquez
authors.forename: Stefan
authors.initials: S
authors.lastname: Hansel
authors.forename: Oliver
authors.initials: O
authors.lastname: Portugall
authors.forename: Charles H
authors.initials: CH
authors.lastname: Mielke
authors.forename: Michael
authors.initials: M
authors.lastname: von Ortenberg
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hauge
authors.forename: Matteo
authors.initials: M
authors.lastname: Pasquali
authors.forename: Junichiro
authors.initials: J
authors.lastname: Kono
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D002244:Carbon / Q000737:chemistry*; D004574:Electromagnetic Fields; D008027:Light; D018625:Microscopy, Atomic Force; D015233:Models, Statistical; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012212:Rheology; D013057:Spectrum Analysis; D013499:Surface Properties; D013997:Time Factors
chemical_list: D037742:Nanotubes, Carbon; D002244:Carbon