Search results for "Materiali"
showing 10 items of 876 documents
Phase separation of polymer blends in solution: A case study
2016
Abstract The phase behavior and phase separation features of the quaternary system poly- l -lactide (PLLA)/poly-rac-lactide (PLA)/dioxane/water were investigated. Experiments were performed with fixed total polymer concentration of 6 wt%, by varying the PLLA/PLA weight ratio. Blend weight compositions examined were 100/0, 80/20, 50/50, 20/80 and 0/100, at fixed dioxane/water weight ratio (87/13). Cloud point measurements reported that the demixing temperatures of blends are close to PLLA in the same mixed solvent, in line with the calculated spinodals. As regards to foam preparation, above the PLA cloud point, morphology is similar to pure PLLA foams; conversely, below PLA cloud point, the …
Structural, Spectroscopic and Electrical Features of Undoped and Mn Doped LiTi2(PO4)3
2010
The study of the ionic conducting material LiTi2(PO 4)3 and of its Mn-substituted derivate reveals that the Mn distribution is strictly related to the synthetic method. The results of the structural refinement of X-ray and neutron (ToF) powder diffraction data and of XPS analysis demonstrate that Mn2+ ions are located on the lithium octahedral site, while Mn3+ and Mn4+ ions occupy the titanium ones. The Mn2+ amount on the lithium site seems to be the main factor responsible for the conductivity decrease observed in doped samples. The EPR spectra evidence clustering effects of Mn on both Li and Ti sites and the presence of more insulated Mn2+ ions. The effect of the major Mn amount on Ti sit…
Proprietà e uso degli impermeabilizzanti: classificazione e caratteristiche
2014
L'articolo presenta i risultati di uno studio condotto sui sistemi di impermeabilizzazione dell'involucro edilizio.Viene proposta una classificazione dei prodotti in commercio rispetto: al materiale costituente, alle prestazioni ed al tipo di commercializzazione.Lo studio affronta problematiche tecnologiche ma anche normative in modo da fornire uno strumento per la scelta più appropriata in relazione alle richieste dell'utenza.
NUOVI MATERIALI RICICLABILI PER LA CATALISI ETEROGENEA
2011
Particle surface engineering effect on the mechanical, optical and photoluminescent properties of ZnO/vinyl-ester resin nanocomposites
2007
Zinc oxide (ZnO) nanoparticles functionalized with a bi-functional coupling agent methacryloxypropyl-trimethoxysilane (MPS) were used to fabricate a vinyl-ester resin polymeric nanocomposite, which shows an improved interfacial interaction between the particle and matrix. As a result, in comparison to the unmodified particle-filled nanocomposites, the functionalized particle-filled composites possessed higher resistance to thermal degradation, and demonstrated improved UV shielding and enhanced photoluminescent properties. The more uniform particle dispersion, passivation of the particle surface with MPS and increased oxygen vacancies were justified to contribute to the increased thermal st…
DIELECTRIC PROPERTIES OF EPOXY RESIN COMPOSITES FILLED WITH NANOCARBON INCLUSIONS
2013
The epoxy resin composites with various carbon additives were investigated in the frequency range of 20 Hz - 3 GHz at temperatures from room to 500 K. The dielectric properties were found to be strongly impacted by percolation threshold. The lowest percolation threshold (< 0.25 wt.%), was observed in composites with single-walled carbon nanotubes.
Hybrid aerosol assisted atmospheric pressure Chemical Vapour Deposition: a facile route toward nano-composite thin films?
2009
A hybrid chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nano-particles and the use of a surfactant molecule; tetraoctylammonium bromide (TOAB), is discussed. The films are fully characterised and it is shown that micro-structural changes lead to an enhancement of thermochromic properties, whilst gold nano-particles lead to a change in the films optical properties. Optical data is used in energy modelling studies to elucidate the films potential as an energy saving coating in architectural glazing.
Sperimentazione di materiali nanostrutturati in ambito archeologico
2009
Nanotecnology in restoration: cleaning and consolidation of stonework
2012
This paper describes a project using nanotechnology to improve the characteristics of reliability, compatibility and resistance over a period of time, of products for the restoration and conservation of structures of historic-artistic value, through experimentation with nano-structured materials. The research project specifically tackles two issues, with regard to cleaning and consolidation, testing the new products on samples of stone material taken from the archaeological site at Morgantina (in the centre of Sicily).
Nanotecnologie in Edilizia. Innovazione tecnologica e nuovi materiali per le costruzioni
2010
La presente pubblicazione esplora il tema dell'innovazione edilizia confrontandosi con una questione complessa, quale quella rappresentata dalla nanotecnologia, indagando sul rapporto tra innovazione tecnologica e architettura dalla fine del sec. XIX sino ai nostri giorni, sottolineando soprattutto il forte legame tra l'uso di materiali innovativi e la progettazione architettonica, un filo che lega l'architettura all'avvento del ferro, del vetro, del cemento armato, per introdurre al tema delle nanotecnologie in edilizia, forse, la nuova frontiera dell'innovazione.