Papers by Author: Iñaki Mondragon

Abstract: In this work, different types of nanostructured systems containing azobenzene groups were studied. With that aim, firstly, novel azo-functionalised block copolymers (BCP) were synthesized from epoxidized poly (styrene-b-butadiene-b-styrene) (SBS) modified with azobenzene units by one-step facile reaction between the epoxy groups and an azo-amine. The epoxy/amine reaction was verified by Fourier transform infrared spectroscopy. In addition, the effect of covalent attachment of the azobenzene moieties was investigated by analyzing the morphology and the optical anisotropic response of the resulting azo-containing BCP, with respect to solution mixing of the azobenzene as a guest in the BCP host without chemical bonding. On the other hand, epoxidized SBS was also used as template for the generation of nanostructured thermosetting epoxy matrices with azobenzene groups covalently linked. This BCP can self-assemble in the epoxy matrix to produce microphase-separated domains, thanks to the selective segregation of polystyrene blocks due to reaction induced microphase separation. In this case, the influence of the azobenzene content and the amount of epoxidized SBS on the generated morphologies and the photo-induced anisotropy was studied.

Abstract: The main aim of this work was the generation of novel smart materials, in this case thermo-responsive inorganic/organic meso/nanostructured hybrids based on different low molecular weight liquid crystals (LC) and conductive rutile TiO₂ nanoparticles. LC as partially miscible with polystyrene (PS) was well-dispersed using amphiphilic poly (styrene-b-ethylene oxide) block copolymers (PS-b-PEO). Simultaneously, LC was used as surfactant for conductive rutile TiO₂ nanoparticles.

Abstract: Novel transparent multiphase nanostructured thermosetting composites with different block copolymer and sol-gel contents have been developed. Morphology of designed systems has been investigated by atomic force microscopy (AFM). Electrostatic force microscopy (EFM) has been used in order to study the conductive properties of prepared hybrid inorganic/organic nanostructured thermosetting systems. Moreover taking into account the optical properties of TiO₂ nanoparticles UV-vis measurements indicate that TiO₂ nanoparticles clearly enhance the UV-shielding efficiency of the inorganic/organic nanostructured thermosetting systems without losing high-visible light transparency.