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Sol–gel derived 45S5 bioglass: synthesis, microstructural evolution and thermal behaviour

In this work, the 45S5 bioactive glass was synthesized through an aqueous sol–gel method. Characteristic functional groups were evidenced by Fourier transform infrared spectroscopy, the thermal behaviour was investigated by thermogravimetric and differential thermal analysis, crystallization kinetics and phase evolution were followed by X-ray diffraction measurements. The sintering behaviour of the sol–gel derived 45S5 was then studied by dilatometry and the microstructural evolution was followed step-by-step, interrupting the thermal cycle at different temperatures.

Nanostructured Materials for Sensing

Materials having nanometric dimensions are able to improve their functional properties, which allow their exploitation in highly performing sensors. Materials with at least one dimension smaller than 100 nm are classified as nanostructured.

Comprehensive Characterization of Large Piezoresistive Variation of Ni-PDMS Composites

This work presents a comprehensive investigation of the piezoresistive response of a metal-polymer composite for robotic tactile sensor application. Composite samples, based on nickel nanostructured conductive filler in a polydimetihylsiloxane (PDMS) insulating elastomeric matrix, were prepared changing several process parameters like thickness, composition of the polymer and nickel filler content. A variation of electric resistance up to nine orders of magnitude under applied uniaxial load was measured in the fabricated samples.

Epoxy/BaTiO3 Light-Cured Composites as Organic Capacitors

Epoxy/BaTiO3 hybrid materials are prepared as good candidates for organic capacitors. The hybrid system is cured by using camphorquinone and a iodonium salt through a free-radical promoted cationic polymerization using a long-wavelength tungsten halogen lamp. The cured films are fully characterized. Morphological characterization shows a well-dispersed inorganic phase within the organic matrix. Electrical characterization demonstrates a linear increase of the dielectric constant with increasing filler content, while low dielectric loss values are obtained.

The Contribution of Natural Hydroxyapatite to the Development of Bone Substitutes

Several hydroxyapatite (HAp) synthesis routes, such as solid state reactions, hydrothermal methods, wet procedures have been widely investigated. At the same time, in the last years many alternative methods to produce HAp, exploiting fish, bovine or pig bones, have been developed; among them the most used are thermal processes as well as subcritical water or alkaline hydrothermal routes. This paper deals with a natural HAp nanopowder extracted from pig bones by a treatment with hot NaOH solution.

Actuators based on intrinsic conductive polymers/carbon nanoparticles nanocomposites

New polyaniline (PANi) synthesis was performed starting from non-toxic N-phenil-p-phenylenediamine (aniline dimer) using reverse addition of monomer to oxidizing agent, the synthesis allows to produce highly soluble PANi. Several types of doped PANi were prepared to be used on electromechanical active actuators. Different techniques were used to include carbon nanoparticles such as carbon nanotubes and graphene. Bimorph solid state ionic actuators were prepared with these novel nanocomposites using a variety of supporting polymers.

Development of Hybrid Piezoelectric Materials for Tactile Sensing

As the robotics is moving its interest from the machine tools for industrial production to biomimetic, even human-like systems, the need for materials that fulfill skin role arises. Skin presents a structure that has multiple roles such as protection and tact. The basic requirements for a skin mimetic material are flexibility and a measurable physical property triggered by the pressure. In this work hybrid piezoelectric materials are prepared and characterized. The flexibility of materials is assured by the polymeric matrices while ceramic oxide fillers grant a piezoelectric response.

HVOF hard coatings for the enhancement of erosion resistance of components to be applied in water treatement implants

The aim of this work was to evaluate the hydro-erosion resistance of HVOF thermal sprayed coatings suitable to coat parts to be applied in the water treatment equipments and implants. Several coating materials such as Inconel 625, Inconel 625+10%vol. Al2O3, Stellite 6, AISI 316 stainless steel and WC-Co were applied on steel or cast iron substrates with different geometries. The derived specimens were tested in a special slurry abrasion/hydro-erosion test rig, that simulates the operating conditions of wet erosive wear.

Optimal microstructural design of a catalytic premixed FeCrAlloy fiber burner for methane combustion

New catalytic FeCrAlloy premixed fiber burners for natural gas combustion in domestic applications were developed according to an accurate microstructural design consisting of subsequent optimized steps: (i) optimal preoxidation of the FeCrAlloy fiber mat so as to develop the best possible Al2O3 layer for simultaneous prevention of deeper fiber oxidation at high temperature and optimal catalyst anchoring over the fiber surface, (ii) deposition via the either spray-pyrolysis or wash-coating technique of a previously developed perovskite catalyst (LaMnO3â 17MgO), and (iii) extensive testing of t