Characterization of composites with aligeaed carbon nanotubes (cnts) as reinforcement. Caracterización de materiales compuestos con nanotubos de carbono (cnts) alineados como refuerzo
- Autores: Enrique José García Vidorreta
- Directores de la Tesis: Antonio Miravete de Marco (dir. tes.)
- Lectura: En la Universidad de Zaragoza ( España ) en 2006
- Idioma: español
- Tribunal Calificador de la Tesis: Conrado Rillo Millán (presid.), Jesús Cuartero Salafranca (secret.), Emilio Larrodé Pellicer (voc.), Wolfgang K. Maser (voc.), Ana Benito (voc.)
- Materias:
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- Resumen
Carbon nanotubes' (CNTs) superlative combination of electrical, thermal, and especially mechanical properties make them ideal candidates for composite reinforcement. Nanocomposites and hybrid composite architectures employing traditional advanced composites and CNTs offer significant potential mechanical and multifunctional performance benefits. CNT/polymer composites and two different hybrid architectures are experimentally investigated in this work. A novel process for rapidly growing dense, long, high-quality aligned CNT forests is employed. The first architecture is comprised. of aligned fibers with CNTs grown radially on their surface. For the second architecture, dense forests of vertically aligned CNTs are placed between the plies of a laminate, in the through-thickness direction. Fundamental issues related to realizing hybrid composite architectures are investigated experimentally: wetting of the CNTs by commercially available polymers for the different architectures, effective reinforcement of the polymer matrices due to the addition of CNTs, retention of mechanical (stiffness and strength) properties of the fibers after the CNT growth process, and transplantation of CNT forests from a substrate to the surface of prepreg. Wetting of CNT forests by several commercial polymers (including a highly-viscous epoxy) is demonstrated at rates conducive to creating a fully-dispersed CNT( matrix region for the two hybrid architectures previously described. Direct measurements of the mechanical properties of nanocomposites are reported for the first time in the literature. Increases in the Young's modulus of the polymer as high as 220% with just 2% volume fraction of aligned CNTs are observed. Equivalent reinforcement had been obtained previously by other authors with 5% volume fraction of randomly oriented CNTs. Single-fiber tension tests indicate no mechanical degradation (stiffness and strength) for alumina fibers undergoing the CNT growth process. Results showing t
