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Novel materials based on mixtures of immiscible polymers, namely poly (3-hexylthiophene-2,5-diyl) and poly (methyl methacrylate) (P3HT/PMMA), with dispersed phosphorene (2D-bP), obtained by liquid-phase exfoliation (LPE) of black phosphorus (bP) or by in situ polymerization technologies, were prepared for the first time. The new materials were characterized by Raman, UV–Vis, solid state 31P NMR spectroscopies, X-ray diffractometry (XRD), size exclusion chromatography (SEC), morphological (SEM), topographical (AFM) and thermal analysis (DSC and TGA) to investigate the physio-chemical features of both components, polymers and phosphorene owing the composites preparation. Good distribution of the nanoflakes, which preserve their structure and resulted intercalated and partially exfoliated, was achieved thanks to established interactions at the interface between the 2D-bP flakes and the polymers, especially with the P3HT phase, changing the morphology and topography of the mixtures. The preferential allocation of 2D-bP in P3HT, besides inducing a particular polymers phase segregation (a vertical phase separation with P3HT continuous phase onto the surface) encouraged testing these materials as an active layer in Organic Field Effect Transistor (OFET) devices. The data collected showed that the introduction of 2D-bP in P3HT/PMMA polymer mixtures is somewhat promising, giving an increase in mobility up to an order of magnitude with respect to the corresponding 2D-bP-free mixture.

PLA-based composites were prepared by mixing the polymer in the melt with organophilic Mg/Al LDH and Mg Stearate. The obtained materials were therefore characterized in comparison with the unfilled PLA with the aim of investigating the relationships between the morphology of the polymer composites and their thermal stability, crystallinity and mechanical properties. The degradative effects induced by the presence of O-LDH and its organic component (i.e. alkyl carboxylates used as surfactant) were evaluated by analysing the samples with SEC and TGA under standard and modulated conditions, in the presence of nitrogen and air. The collected results proved that the main effects on degradation are due to inorganic reactive species and to increased interfacial surface owing to intercalated/exfoliated morphology. The main thermal transitions of the composites were studied by XRD and DSC (even in modulated conditions) before and after annealing processes at different temperatures. The results inherent to the percentage of crystallinity, the content of rigid amorphous fraction (RAF), and the main size of crystalline domains were discussed by considering the filler nature/content, its dispersion degree in polymer matrix and the annealing temperature. By crystallization at 80 °C the filler promoted both RAF and crystallites size. Unlike unfilled PLA, the composites showed an increase of the stiffness and a general loss of ductility which were tentatively ascribed to annealing at 80 °C and to the extent of interfacial interactions.

This research activity aims at investigating the hydrogen embrittlement of Maraging steels in connection to real sudden failures of some of the suspension blades of the Virgo Project experimental apparatus. Some of them failed after 15 years of service in working conditions. Typically, in the Virgo detector, blades are loaded up to 50-60% of the material yield strength. For a deeper understanding of the failure, the relationship between hydrogen concentration and mechanical properties of the material, have been investigated with specimens prepared in order to simulate blade working conditions. A mechanical characterization of the material has been carried out by standard tensile testing in order to establish the effect of hydrogen content on the material strength. Further experimental activity was executed in order to characterize the fracture surface and to measure the hydrogen content. Finally, some of the failed blades have been analyzed in DICI-UNIPI laboratory. The experimental results show that the blades failure can be related with the hydrogen embrittlement phenomenon.