Francisco Jose Torres

New sensing devices part 1: indole-containing polyamines supported in nanosized boehmite particles

The synthesis, characterisation and optical properties of new sensing systems made by attaching different polyamine chains functionalised with an indole fluorophore to a boehmite matrix is reported for the first time. Firstly, a family of tri(alkoxy)alkylpolyaminosilanes have been reacted with indole-3-carboxaldehyde to form the corresponding Schiff bases which were reduced with sodium borohydride. The anchoring to the surface of the boehmite nanoparticles was carried out by reacting the precursors with the hydroxyl groups available in the surface of the support. The characterisation of the materials by elemental microanalysis, X-ray powder diffraction, CP-MAS 29Si NMR and electron microscopy unambiguously proved that covalent anchorage had occurred. Steady-state fluorescence emission studies showed that these materials present a very efficient sensing behaviour for hydrogen ions, metal ions such as Cu2+ and Zn2+ and for the anionic nucleotides ATP, ADP and AMP.

Naphthalene-containing polyamines supported in nanosized boehmite particles

Boehmite nanoparticles with covalently linked polyamine chains functionalized with naphthalene fluorophores have been prepared and characterized. The characterization of the materials by elemental microanalysis, X-ray powder diffraction, MAS 29Si NMR and electron microscopy unambiguously prove that the covalent anchorage had occurred. Steady-state fluorescence emission studies show that the luminescent properties of the modified nanoparticles are sensitive to changes in concentration of hydrogen ions, metal ions and anionic nucleotides such as ATP. The behaviour of the attached materials in aqueous solution is parallel to the behaviour of the single fluorophoric polyamines. Comparisons are established with analogous systems containing indole as a fluorophore.

Ni-containing spinel aluminates glass-ceramic materials obtained from cordieritic bulk glasses

Monolithic glasses with compositions 2MO � 2Al2O3 � 5SiO2, being M ¼ Ni and equimolar mixtures of Ni and Mg, were prepared at 1650 C by melting mixtures of raw materials. The crystallization of monoliths was produced by heattreatment at several temperatures up to 1200 C. The crystallization sequence was followed by differential thermal analysis (DTA), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) and diffuse reflectance spectroscopies. Surprisingly, the only crystalline phase formed after heating up to 1100 C was a nickel-containing aluminate spinel for both compositions. The microstructural characterization indicated the volume crystallization of well formed octahedral crystals of spinel with smaller size than 500 nm. Finally, it has been proved that nickel-containing aluminosilicate glasses could be converted into l -o ra-cordieriteand spinel-based glass-ceramics by thermal treatment of powdered glasses and monolithic bodies, respectively. 2003 Elsevier Science B.V. All rights reserved.

Urban Development and Cultural Policy “White Elephants”: Barcelona and Valencia

Abstract The importance of culture in defining new models of local development has been increasingly emphasized. However, less attention has been paid to the influence of local development models on local cultural policy. This article will focus on analysing two cities that have used culture as a central element in their economic and urban development. In both cases, they have followed different strategies but the two have finally finished generating two “white elephants”: the Universal Forum of Cultures in the case of Barcelona and the City of Arts and Sciences in the case of Valencia. From a comparison of the two cases, the paper analyses the causes of this urban phenomenon, which combines cultural legitimation, wasteful investments, financial and social unsustainability and, last but not least, corruption. These four characteristics of cultural white elephants express the depletion of a neoliberal city model based on real estate speculation and tourism, which de facto relegates culture – in spite of discourses about social cohesion and sustainability – as an instrument of urban branding and elite socio-economic domination.