Dynamics of functionalized single wall carbon nanotubes in solution studied by incoherent neutron scattering experiments

• Published in: Journal of physics. Condensed matter 2008-03, Vol.20 (10), p.104208-104208 (6)
• Main Authors: Urbina, A, Miguel, C, Delgado, J L, Langa, F, Díaz-Paniagua, C, Jiménez, M, Batallán, F
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; General and physical chemistry; Materials science; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/20/10/104208

We have studied, by incoherent neutron scattering experiments, the dynamics of a colloidal suspension of functionalized single wall carbon nanotubes (SWNTs). The nanotubes have been functionalized with pentyl ester groups attached at the ends and suspended in deuterated toluene with a concentration of 2.6 mg SWNT/1 ml of deuterated toluene. The experimental techniques were incoherent elastic neutron scattering (IENS) and incoherent quasielastic neutron scattering (IQNS). In the temperature range between 4 K and 300 K, three phases were observed by IENS measurements: a solid phase for TTm. Furthermore, in the high temperature range of the undercooled liquid phase, hysteresis loops in the heating and cooling scans were observed. The lower limit of the hysteresis loop defines the critical crossover temperature Tc. IQNS measurements in the liquid phase and a cooling scan of the undercooled liquid phase were performed. Three different quasielastic peaks were identified, two in the liquid phase and another one in the undercooled liquid phase. The widths of the quasielastic peaks are discussed as a generalized diffusion function which can be factorized as a temperature dependent diffusion function and a Q dependent structure function. From the comparison of the diffusion function with the viscosity of toluene, we conclude that two components are in the long-time range Brownian motion and the other one in the short-time range Brownian motion.