Confining reactions in a droplet: synthesis of mofs, cofs and composites using spray-drying

• Autores: Luis Carlos Garzón Tovar
• Directores de la Tesis: Daniel Maspoch Comamala (dir. tes.), Inhar Imaz (codir. tes.)
• Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2018
• Idioma: español
• Tribunal Calificador de la Tesis: Jorge Andrés Rodríguez Navarro (presid.), José Giner Planas (secret.), Emilio Pardo (voc.)
• Programa de doctorado: Programa de Doctorado en Química por la Universidad Autónoma de Barcelona
• Materias:
  • Química
    • Química inorgánica
• Enlaces
  • Tesis en acceso abierto en:  TESEO  TDX 
• Resumen

  • A new age in materials chemistry started with the discovery of Metal-Organic Frameworks and Covalent-Organic frameworks. In particular, the introduction of reticular chemistry represented a revolutionary strategy that gave chemists infinite opportunities toward the design and construction of novel functional materials with exceptional properties, such as their high porosity, high structural/compositional flexibility and low densities (for COFs). Indeed, these properties render MOFs and COFs as promising materials for multiple applications of commercial interest, including gas storage and separation, catalysis, sensing, drug delivery, water harvesting and adsorptive heat transformation systems. These possibilities have promoted a rapid and explosive pace of expansion in this field and as a result, academia and industry have begun to propose several initiatives towards the commercialization of these porous materials. However, despite these efforts, the scientific community has also recognized that the use of these materials could be limited by the challenges pertaining to their production methods at large scale since harsh conditions are usually needed to synthesize them. In this sense, novel approaches for their synthesis have been developed recently. In particular, the spray-drying method has emerged as a promising technology for the synthesis of MOFs at large scale. However, spray-drying is still in its embryonic stage and therefore, there are many challenges that need to be overcome.

    In this Thesis, we have developed new strategies to synthesize MOFs. In particular, we describes a new methodology based on coupling two processes —spray-drying and continuous flow— for continuous synthesis of MOFs assembled from high-nuclearity secondary building units (SBUs). In addition, we demonstrated that the spray-drying-continuous flow method can be used not only to synthesize MOF superstructures but also to incorporate functional species, thereby providing a new route for the synthesis of MOF-based composites. In this thesis, we extend the use of spray-drying technique to covalent chemistry. To this end, we show that different imines can be synthesized from Schiff-base condensation reactions between discrete aldehydes and amines using the spray-drying. We also show that this chemistry can be extended to post-synthetically modify MOFs. For example, we show the post-synthetic modification of two MOFs, the amine-terminated UiO-66-NH2 and the aldehyde-terminated ZIF-90. Moreover, we demonstrate that the Schiff-base condensation reactions can be extended to the synthesis of COFs. Thus, we prove that spherical superstructures made from the assembly of imine-based COF nanocrystals can be obtained by combining the spray-drying technique with a dynamic covalent chemistry process. In addition, we show that this methodology enables the integration of other functional materials such as dyes and magnetic nanoparticles into these superstructures forming COF-based composites.