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Visar resultat 1 - 5 av 174 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Chemistry of Carbon Nanostructures : Functionalization of Carbon Nanotubes and Synthesis of Organometallic Fullerene Derivatives

   Författare :Claes-Henrik Andersson; Helena Grennberg; Nazario Martín León; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon nanotubes; Fullerenes; Purification; Functionalization; Organometallic complexes; Kemi med inriktning mot organisk kemi; Chemistry with specialization in Organic Chemistry;

   Sammanfattning : This thesis is based on two main parts. The first part concerns purification and functionalization of carbon nanotubes (papers I-III), and the second part is related to the synthesis of organometallic fullerene derivatives (papers IV-VII): Two oxidative methods involving aqueous nitric acid were compared with respect to their capability to introduce carboxylic groups into single walled carbon nanotubes, and several literature methods for esterification and amidation of these groups have been evaluated with focus on efficiency and reproducibility in forming covalently functionalized products soluble in organic media. LÄS MER

3. 2. Cellulose–Assisted Dispersion of Carbon Nanotubes : From Colloids to Composites

   Författare :Alireza Hajian; Lars Berglund; Milo Shaffer; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nanocelluloses; Carbon nanotubes; Composites; Colloids; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : It is a challenge to disperse nanoparticles to obtain a nanostructured composite. This thesis aims at providing a new route to fabricate carbon nanotube (CNT) composites and suggests mechanisms for nanocellulose–CNT interactions. This route is based on unmodified CNT dispersed in water with the help of nanocellulose. LÄS MER

4. 3. Mechanical properties of carbon nanotubes and nanofibers

   Författare :Henrik Jackman; Krister Svensson; Pavel Krakhmalev; Håkan Olin; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atomic force microscopy; bending; carbon nanotubes; deformation; scanning electron microscopy; Young s modulus; carbon nanofibers; mechanical properties; Physics; Fysik;

   Sammanfattning : Carbon nanotubes (CNTs) have extraordinary electrical and mechanical properties, and many potential applications have been proposed, ranging from nanoscale devices to reinforcement of macroscopic structures. However, due to their small sizes, characterization of their mechanical properties and deformation behaviours are major challenges. LÄS MER

5. 4. Towards Controlled Growth and Applications of Carbon Nanotubes

   Författare :Raluca Elena Morjan; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; acetylene; carbon nanotubes; carbon feedstock; chemical vapor deposition; fullerenes; dc-glow discharge plasma; growth mechanism; metal catalyst;

   Sammanfattning : This thesis deals with growth, characterization and application of carbon nanotubes. The methods involved in the production of carbon nanotubes are thermal chemical vapor deposition (T-CVD) and plasma enhanced chemical vapor deposition (PE-CVD). LÄS MER

7. 5. Dispersing Carbon Nanotubes: Towards Molecular Understanding

   Författare :Ricardo M. Ferreira Fernandes; Istvan Furo; Eduardo Marques; Philippe Poulin; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbon nanotubes; dispersion; surfactants; polymers; adsorption; liquid crystals; nuclear magnetic resonance; self-diffusion; Kemi; Chemistry;

   Sammanfattning : Carbon nanotubes (CNTs) exhibit unique and fascinating intrinsic electrical, optical, thermal or mechanical properties that lead to a plethora of potential applications in composite materials, electronics, energy storage, medicine, among others. However, the manipulation of nanotubes is not trivial and there are significant difficulties to overcome before achieving their full potential in applications. LÄS MER