Ricerc@Sapienza

Poly(Ethylene 2,6‐Naphthalate)—PEN has been used as matrix for laminates with the aim to develop woven fiber reinforced composites with a service temperature as high as 100°C. Three different classes of fibers have been considered as reinforcement in woven fabric form: carbon, polymers (Twaron and Vectran) and mineral (basalt). Composites were manufactured by using the film stacking technique, alternating layers of balanced plain weave fabrics (0/90) and films of amorphous PEN. The manufacturing process was optimized to obtain a good impregnation of fibers and very low void content.

TiO2-SiO2 mixed oxides have been prepared by the sol–gel technique from tetrabutyl orthotitanate and tetraethyl orthosilicate. The prepared materials were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, nitrogen physisorption, Fourier-transform infrared spectroscopy (FT-IR) and x-ray photoelectron spectroscopy (XPS). The results indicate that the TiO2-SiO2 mixed oxides have a large surface area and a nanoscale size. FT-IR spectra show that Ti atoms are bonded to silica by oxygen bridging atoms in Ti-O-Si bonds.

Stellite 6 is a cobalt-base alloy commonly used for coatings useful in wear and corrosion protection of several components over a wide range of temperatures. Stellite coatings can be obtained by many deposition techniques: plasma transferred arc (PTA) is certainly an optimal choice that gives thick, dense coatings, but thermal spray techniques like high velocity oxy-fuel (HVOF) are also widely used to deposit such materials.

Mixing of a diffusing species entrained in a three-dimensional microfluidic flow-focusing cross-junction is numerically
investigated at low Reynolds numbers, 1 ≤ Re ≤ 150 , for a value of the Schmidt number representative of a small solute
molecule in water, Sc = 103 . Accurate three-dimensional simulations of the steady-state incompressible Navier–Stokes equations
confirm recent results reported in the literature highlighting the occurrence of different qualitative structures of the

In this study, we report about the preparation of magnetic polymer nanocomposites on the basis of isotactic polypropylene and magnetite Fe3O4 nanoparticles. The structure and composition of polymer nanocomposite materials have been studied by scanning electron microscopy, atomic force microscopy, and X-ray dispersive analysis. The magnetic properties of polymer nanocomposites based on PP+Fe3O4have been investigated.

Unprecedented hydrolysis reactions are observed in the gas phase in clusters containing doubly-charged vanadium oxides and hydroxide anions, SO2and H2O. The experimental and computational study shows the cooperative effects of the vanadium species, V2O62-and HV3O92-, and sulfur dioxide on the enhancement of the hydrogen bonds of water that allows the acid-base reaction and charge separation in the doubly-charged ion.