Momota Hiroshi, Yokoi Hiroyuki, Takamasu Tadashi
Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
J Nanosci Nanotechnol. 2010 Jun;10(6):3849-53. doi: 10.1166/jnn.2010.1976.
Magnetically aligned and highly dispersed single-walled carbon nanotubes (SWNTs)-gelatin composite films were fabricated on a quartz substrate of newly designed disassemblable sample cells. After an SWNTs-gelatin composite sol in each sample cell was exposed to vertical DC magnetic fields to 28 T during the sol-gel transition, a side plate with a polytetrafluoroethylene film attached to the inner surface was removed from the sample cell carefully, and the composite gel left on the other side plate made of quartz was dehydrated in a nonmagnetic circumstance. We have found that the alignment of SWNTs is retained in uniform composite films obtained after the nonmagnetic drying process. Both polarized absorption measurements and polarized Raman scattering measurements were performed in order to confirm the alignment of SWNTs in the composite films consistently. The optical anisotropy of the composite films increased somewhat superlinearly as a function of the magnetic field applied during the sol-gel transition and reached to 0.13 at 28 T. The nonmagnetic drying process would make it easy to apply higher magnetic fields to the fabrication of aligned SWNTs films as it consumes resources to keep operating high field magnets such as hybrid magnets during the drying process.
在新设计的可拆卸样品池的石英基板上制备了磁取向且高度分散的单壁碳纳米管（SWNTs）-明胶复合薄膜。在溶胶-凝胶转变过程中，将每个样品池中的SWNTs-明胶复合溶胶暴露于28 T的垂直直流磁场中后，小心地从样品池中取出内表面附着有聚四氟乙烯薄膜的侧板，将留在由石英制成的另一侧板上的复合凝胶在无磁环境中脱水。我们发现，在非磁性干燥过程后获得的均匀复合薄膜中，SWNTs的取向得以保留。为了始终如一地确认复合薄膜中SWNTs的取向，进行了偏振吸收测量和偏振拉曼散射测量。复合薄膜的光学各向异性随溶胶-凝胶转变过程中施加的磁场呈超线性增加，在28 T时达到0.13。非磁性干燥过程将使在制备取向SWNTs薄膜时更容易施加更高的磁场，因为在干燥过程中保持诸如混合磁体等高场磁体运行会消耗资源。
