Functionalization and large scale assembly of carbon nanotubes
PhD thesis (Dissertation), TU Dresden, January 2016
Assembly of nanoparticles provides effective building blocks for physical, chemical and biological systems which have surprisingly collective intrinsic physical properties. One-dimensional nanomaterials are one of the most spectacular and promising candidates for technological application in the field of nanotechnology. Single-walled carbon nanotubes represent an anisotropic and perfectly one-dimensional group of nanomaterials with extraordinary electronic, mechanical, chemical and thermal properties. Usually, such nanoparticles are dispersed in solution, and for any application it’s necessary to bring them on the surface in an organized way. However, to exploit its full potential and to ensure efficient scale-up, self assembly of such nanoparticles is absolutely essential. The aim of this work is to develop new strategies for alignment by self assembly of such one-dimensional nanomaterials like carbon nanotubes using combination of different conventional techniques.
This includes a functionalization study with new strategy for hybrid bio-functionalization of carbon nanotubes which could have potential application in drug delivery, genetic engineering and biosensors. The possibility to make hybrid structure functionalization by attaching ss-DNA backbone to the positively charged head group of a cationic surfactant by ionic interaction is demonstrated. Localization of nanoparticles at liquid-liquid interfaces by manipulating the particle surface energy is an upcoming area with great potential for research and opens a window to fabricate self assembled interfacial structured hybrid materials with unique properties. In this direction, a strategy for alignment of carbon nanotubes at liquid-liquid interfaces using dielectrophoresis is also investigated. Finally, a new and unique strategy for large scale alignment of carbon nanotubes is presented by combing dielectrophoresis during Langmuir-Blodgett assembly process. The degree of alignment is verified using polarized micro Raman spectroscopy and direction dependent electrical conductivity measurements.