Synthesis and physico-chemical characterization of Au/TiO2 nanostructures formed by novel "cold" and "hot" nanosoldering of Au and TiO2 nanoparticles…

2011

Abstract A novel approach to synthesize Au/TiO2 nanostructures with interesting optical properties is presented and discussed. It is based on the nanoparticle “cold” or “hot” nanosoldering occurring when two water suspensions of Au and TiO2 nanoparticles are merely mixed at room temperature or laser irradiated after mixing. Thanks to the high fraction and mutual reactivity of surface species, immediately after the mixing process, the encounters between Au and TiO2 nanoparticles in liquid phase are enough for “cold” nanosoldering of gold nanoparticles onto TiO2 nanoparticles to occur. The optical characterizations show that this fast process (timescale less than 1 min) is followed by a slowe…

Template Electrochemical Growth and Properties of Mo Oxide Nanostructures

2014

This work is aimed at studying the growing process of nanostructures electrodeposited from molybdate aqueous solutions at different pH values into pores of polycarbonate membrane templates. The challenging issue was the opportunity to investigate a rather complex deposition process in a confined ambient, where electrochemical conditions are quite different from those usually established for deposition on a flat substrate. Nanostructures were grown from a bath containing Mo7O246– (NH4)6Mo7O24·4H2O) at different concentrations (50–100 g/L), at a constant cathodic current density of 2 mA/cm2 (electrodeposition area ∼8 cm2). Nanostructured deposit was characterized by XRD, EDS, Raman, XPS, and …

Highly untangled multiwalled carbon nanotube@polyhedral oligomeric silsesquioxane ionic hybrids: Synthesis, characterization and nonlinear optical pr…

2015

Abstract Highly de-bundled multiwalled carbon nanotube (MWCNT) polymer nanohybrids were obtained via ionic assembling of a novel POSS-polyimidazolium-ionic liquid (POSS = polyhedral oligomeric silsesquioxanes) with oxidized MWCNTs. The synthesis, accomplished by a simple bilayer chloroform/water metathetical reaction process, was promoted by the high surfactant properties of POSS-imidazolium-polyionic liquid, which assisted the effective de-bundling, dispersion and purification of the as prepared POSS@MWCNT polymers in organic media, via a surface coating mechanism. The presence of remarkably intense radial breathing modes (RBMs) in Raman spectra, both in solution and as solid, corroborates…

Sensitization of nanocrystalline TiO2 with 3,4,9,10-perylene tetracarboxylic acid

2014

Optical properties of 3,4,9,10-perylene tetracarboxylic acid (PTCA) in the presence of nanocrystalline TiO2 (nominal diameter 15 nm) have been investigated in ethanol solution and in the solid state by UV-Vis absorption spectroscopy and steady-state and time-resolved fluorescence. Experimental results show that, in ethanol, the presence of TiO2 nanoparticles causes significant changes in the typical absorption and fluorescence bands of PTCA and in the fluorescence relaxation time. Similar effects are also detected in solid samples, obtained by electrospray deposition technique. The nonlinear optical properties of the PTCA-TiO2 in ethanol solutions were investigated using the single-beam Z-s…

Specific Heat and Transport Functions of Water

2020

Numerous water characteristics are essentially ascribed to its peculiarity to form stronghydrogen bonds that become progressively more stable on decreasing the temperature. However, thestructural and dynamical implications of the molecular rearrangement are still subject of debate andintense studies. In this work, we observe that the thermodynamic characteristics of liquid water arestrictly connected to its dynamic characteristics. In particular, we compare the thermal behaviourof the isobaric specific heat of water, measured in different confinement conditions at atmosphericpressure (and evaluated by means of theoretical studies) with its configurational contribution obtainedfrom the value…

Distretti turistici in Sicilia: una proposta di analisi dell’attrattività turistica

2012

Local Tourism System in Sicily: a proposal for the identification through spatial classification with the constraints of contiguity

2012

The theoretical approach to Tourism Economics is based on the systemic nature of tourism, stemming both from the heterogeneity of the tourist package and from the existing complex interactions among destinations, firms, tourists. The systemic nature of tourism and the identification with its geographical representation, that is the destination, introduce the concept of Local Tourist System (LTS). This systemic nature has also been recognized by the Italian legislation by creating of an economic policy instrument, named Local Tourist System: “We call local tourist systems, homogeneous or integrated tourist environments, which include territories belonging even to different regions characteri…

Sistemi Turistici Locali in Sicilia: un approccio all’identificazione

2012

Molti interventi di politica economica finalizzati allo sviluppo locale assumono come riferimento il territorio. Tale affermazione all’apparenza scontata esprime un concetto fondamentale, non è possibile né tanto meno auspicabile, formulare strategie è percorsi di sviluppo per una data area senza un’analisi approfondita del territorio delle sue caratteristiche, dei suoi punti di forza e di debolezza. In più è determinante che all’analisi segua la sintesi, intesa come momento di individuazione dello specifico contesto geografico cui destinare gli sforzi di programmazione. Il contributo che si vuole fornire al dibattito sui Sistemi Turistici Locali è relativo all’individuazione di aree omogen…

Una metodologia integrata per l’analisi della Competitività di una Destinazione Turistica: un contributo all’analisi una piattaforma informatica

2014