New trends in cement systems: interfaces with TiN thin films and modification with titania nanoparticles

• Autores: Elena Cerro Prada
• Directores de la Tesis: Miguel Manso Silván (dir. tes.), Vicente Torres Costa (dir. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2013
• Idioma: inglés
• Tribunal Calificador de la Tesis: José Manuel Martínez Duart (presid.), Raúl José Martín Palma (secret.), José Pérez Rigueiro (voc.), Jesús Soriano Carrillo (voc.), Rosa Domínguez Gómez (voc.)
• Materias:
  • Ciencias tecnológicas
    • Ingeniería y tecnología del medio ambiente
      • Control de la contaminación atmosférica
• Enlaces
  • Tesis en acceso abierto en: Biblos-e Archivo
• Resumen

  • This doctoral thesis has two objetives: the first investigation is dedicated to the evaluation of TiN thin films as a protection barrier against corrosion of reinforced steel in concrete. To achieve this goal, TiN thin films were prepared by using the magnetron sputtering deposition method. Characterization of the TiN-cement interface was performed by advanced experimental techniques such a XRD, XPS, TGA/TG, SEM and HRTEM. The corrosion parameters of the TiN were studied and its dependence on the cement phases was analysed. The cement paste nanostructure at the interface was investigated focusing on the so-formed C-S-H gel. The interface TiN/cement has shown excellent corrosion resistance against chloride ingress. The cement paste in contact with TiN develops adhesion phases which enrich the passive layer and therefore provide further protection to the whole structure.

    Secondly, we aim to evaluate the feasibility of the application of heterogeneous photocatalysis for the elimination of pollulants from air by modifying cement paste nanostructure with TiO2 nanoparticles prepared by sol-gel. In this work, TiO2 nanoparticles were synthesized by using the sol-gel technology and inserted in the cement paste matrix at the first stage of hydration. Characterization of the prepared TiO2-modified cement was performed. The photocatalytic activity and its dependence on the TiO2 concentration was studied. The cement paste nanostructure after modification was analysed in order to understand the properties of the new material. The results show that TiO2 nanoparticles provide the cement system not only with photocatalytic activity but also promote the formation of C-S-H gel, which is, ultimately, the phase responsible for the mechanical performance of cement-based construction materials.