Authors: H. Younes, H. Hong
Affilation: South Dakota School of Mines and Technology, United States
Pages: 393 - 396
Keywords: functionalized SWNT, alignment, γ-Fe2O3, magnetic field
In this work we describe a new approach to align functionalized single walled carbon nanotubes (SWNTs) by γ-Fe2O3 in the presence of an external magnetic field without using chemical surfactant. Five different functionalized SWNTs are studied. SWNT-SO2OH dissolves completely and a clear alignment is observed. SWNT-COOH disperses well and shows the clear alignment. SWNT-PABS and SWNT-CONH2 disperse poorly and exhibit some kind of alignment. The high entanglement of PABS chain decreases the alignment of SWNT-PABS. The lack of alignment in SWNT-CONH2 is attributed to the non-stable charge on the amide group (the delocalization of the lone pairs of electron on the nitrogen atom). In contrast, SWNT-PEG disperses well and shows a slow alignment process. This may attribute to the electrostatic attraction between the partially negative charged functional group and γ-Fe2O3. The results demonstrate that as long as the charges fit, the functional nanotubes alignment could be reached without chemical surfactant.