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Our research on CNT-NP hybrid structures began as a scientific curiosity. It has advanced to a stage where the methods to produce these hybrid nanostructures are available, and much more attention has been paid to such materials because of their potential widespread applications in many areas. The ESFDA technique can be used to efficiently coat randomly dispersed and verticallyaligned CNTs with various aerosol NPs. An intrinsic NP size selection has been observed during the assembly process. The final NP size distribution and areal density can be controlled through flow residence time/electric field or assembly time, respectively. For vertically-aligned CNTs, the electric field distribution near the CNT surface was computed using a simple model of the CNT as a cylinder with a hemispherical cap; the field enhancement factor increases from the root to the tip of the CNT for the two cases studied. The areal density and size distributions of nanocrystals observed along the CNTs in the vertical array can be rationalized by the variation of the electric field near the CNT surface; however, it is possible that shadowing effects also play a minor role on the variation in the nanocrystal areal density, but not on the nanocrystal size. NP production is not limited to the mini-arc reactor used in our earlier study. NPs produced by other aerosol reactors or by aerosolization of colloidal NPs can also be used for the assembly, although an additional charging device may be needed in some cases. Due to the material independence of electrostatic force, the capability of ESFDA has been greatly expanded. One can imagine that NPs of multiple materials, particularly interweaving metal and semiconductor/magnetic nanocrystals, can be assembled onto CNTs. These interesting multicomponent structures will open up new opportunities in several interdisciplinary fields. While the controlled production of the hybrid nanostructures is being perfected, a pressing area of research is to understand the synergistic interaction between the two nanocomponents, i.e., NPs and CNTs. Equally important is the understanding of the properties of hybrid nanostructures, which can be tailored for various innovative applications.
Product Details :
Genre | : |
Author | : Junhong Chen |
Publisher | : |
Release | : 2010 |
File | : Pages |
ISBN-13 | : 9533070544 |