| Titre : |
Carbon nanotubes as nanoreactors for magnetic applications |
| Type de document : |
texte imprimé |
| Auteurs : |
Xiaojian, Li, Auteur ; Philippe Serp, Directeur de thèse ; Soulantika, Aikaterini, Directeur de thèse |
| Année de publication : |
2014 |
| Langues : |
Anglais (eng) |
| Tags : |
CARBON NANOTUBES MAGNETIC METAL NANOPARTICLES CONFINEMENT EFFECTS POLYMERIZATION OF ISOPRENE COPT AND FEPT NANOWIRES |
| Résumé : |
"Carbon nanotubes (CNTs), because of their unique properties and potential use in a variety of applications, are probably the most studied class of nanomaterials. Functionalized CNTs, which can be easily manipulated and modified by covalent or non-covalent functionalization, appear as new tools in biotechnology and biomedicine. Indeed, CNTs have optical, electronic and mechanical properties that can be exploited in biological or biomedical applications. Metallic magnetic nanoparticles (MMNPs) of the 3d series and their alloys exhibit excellent magnetic properties unlike their oxide counterparts, which can be exploited in biomedicine and ultra-high density magnetic recording. When confined in CNTs nano-materials can have different properties and behaviors compared to bulk materials. Various confinement effects resulting from the interaction between the confined materials and the internal cavities of CNTs provide opportunities for regulating or designing new nanocomposites. This thesis is devoted to the study of a new approach for the development of nanocomposite materials MMNPs@CNTs and their properties. MMNPs of controlled size and shape of Co and Fe were synthesized with novel aromatic ligands as stabilizers. These MMNPs were then selectively introduced into the cavity of CNTs due to repulsive/attractive interactions between the functionalized multi-walled CNTs and the MMNPs. We were then interested in the protection of these nanoparticles from oxidation by air. Thus, confined iron nanoparticles have been coated with polyisoprene. To do this, the surface of the Fe nanoparticles has been modified with a polymerization catalyst by ligand exchange; then, polymerization of isoprene was conducted inside the channel of CNTs. The protection from oxidation by the polyisoprene was evaluated by magnetic measurements after exposure to air. Quite surprisingly, this study showed that the iron nanoparticles the more resistant to oxidation were those obtained after ligand exchange and without polymerization. In this case only, the original properties of the nanoparticles are maintained after venting. Finally, magnetic bimetallic nanostructures (particles or rods) combining Pt and cobalt or iron were obtained and confined in CNTs. Their chemical structure orderings were also studied by thermal annealing studies. The work developed in this thesis opens up new perspectives for the production of new MMNPs@NTC nanocomposites resistant to oxidation." |
| Document : |
Thèse de Doctorat |
| Etablissement_delivrance : |
Université de Toulouse 3Institut National Polytechnique de Toulouse - INPT |
| Date_soutenance : |
24/04/2014 |
| Ecole_doctorale : |
Sciences de la Matière (Toulouse INPT) |
| Domaine : |
Institut National Polytechnique de Toulouse - INPT |
| En ligne : |
http://www.theses.fr/2014INPT0062# |
Carbon nanotubes as nanoreactors for magnetic applications [texte imprimé] / Xiaojian, Li, Auteur ; Philippe Serp, Directeur de thèse ; Soulantika, Aikaterini, Directeur de thèse . - 2014. Langues : Anglais ( eng)
| Tags : |
CARBON NANOTUBES MAGNETIC METAL NANOPARTICLES CONFINEMENT EFFECTS POLYMERIZATION OF ISOPRENE COPT AND FEPT NANOWIRES |
| Résumé : |
"Carbon nanotubes (CNTs), because of their unique properties and potential use in a variety of applications, are probably the most studied class of nanomaterials. Functionalized CNTs, which can be easily manipulated and modified by covalent or non-covalent functionalization, appear as new tools in biotechnology and biomedicine. Indeed, CNTs have optical, electronic and mechanical properties that can be exploited in biological or biomedical applications. Metallic magnetic nanoparticles (MMNPs) of the 3d series and their alloys exhibit excellent magnetic properties unlike their oxide counterparts, which can be exploited in biomedicine and ultra-high density magnetic recording. When confined in CNTs nano-materials can have different properties and behaviors compared to bulk materials. Various confinement effects resulting from the interaction between the confined materials and the internal cavities of CNTs provide opportunities for regulating or designing new nanocomposites. This thesis is devoted to the study of a new approach for the development of nanocomposite materials MMNPs@CNTs and their properties. MMNPs of controlled size and shape of Co and Fe were synthesized with novel aromatic ligands as stabilizers. These MMNPs were then selectively introduced into the cavity of CNTs due to repulsive/attractive interactions between the functionalized multi-walled CNTs and the MMNPs. We were then interested in the protection of these nanoparticles from oxidation by air. Thus, confined iron nanoparticles have been coated with polyisoprene. To do this, the surface of the Fe nanoparticles has been modified with a polymerization catalyst by ligand exchange; then, polymerization of isoprene was conducted inside the channel of CNTs. The protection from oxidation by the polyisoprene was evaluated by magnetic measurements after exposure to air. Quite surprisingly, this study showed that the iron nanoparticles the more resistant to oxidation were those obtained after ligand exchange and without polymerization. In this case only, the original properties of the nanoparticles are maintained after venting. Finally, magnetic bimetallic nanostructures (particles or rods) combining Pt and cobalt or iron were obtained and confined in CNTs. Their chemical structure orderings were also studied by thermal annealing studies. The work developed in this thesis opens up new perspectives for the production of new MMNPs@NTC nanocomposites resistant to oxidation." |
| Document : |
Thèse de Doctorat |
| Etablissement_delivrance : |
Université de Toulouse 3Institut National Polytechnique de Toulouse - INPT |
| Date_soutenance : |
24/04/2014 |
| Ecole_doctorale : |
Sciences de la Matière (Toulouse INPT) |
| Domaine : |
Institut National Polytechnique de Toulouse - INPT |
| En ligne : |
http://www.theses.fr/2014INPT0062# |
|  |
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