Publications by authors named "Alessia Arrigoni"

Germanium (Ge) has long been recognized for its superior carrier mobility and narrower band gap compared to silicon, making it a promising candidate in microelectronics and optoelectronics. The recent demonstration of good biocompatibility, combined with the ability to selectively functionalize its surface, establishes the way for its use in biosensing and bioimaging. This review provides a comprehensive analysis of the most recent advancements in the wet chemical functionalization of germanium surfaces.

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Vibrational spectroscopy allows the investigation of structural properties of pristine and doped poly(3-hexylthiophene-2,5-diyl) (P3HT) in highly anisotropic materials, such as electrospun micro- and nanofibers. Here, we compare several approaches for doping P3HT fibers. We have selected two different electron acceptor molecules as dopants, namely iodine and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ).

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A theoretical approach based on Periodic Boundary Conditions (PBC) and a Linear Combination of Atomic Orbitals (LCAO) in the framework of the density functional theory (DFT) is used to investigate the molecular mechanism that rules the piezoelectric behavior of poly(vinylidene fluoride) (PVDF) polymer in the crystalline β-phase. We present several computational tests highlighting the peculiar electrostatic potential energy landscape the polymer chains feel when they change their orientation by a rigid rotation in the lattice cell. We demonstrate that a rotation of the permanent dipole through chain rotation has a rather low energy cost and leads to a lattice relaxation.

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Feasibility of electrospinning in the manufacturing of sildenafil-containing orodispersible films (ODFs) intended to enhance oxygenation and to reduce pulmonary arterial pressure in pediatric patients was evaluated. Given the targeted subjects, the simplest and safest formulation was chosen, using water as the only solvent and pullulan, a natural polymer, as the sole fiber-forming agent. A systematic characterization in terms of shear and extensional viscosity as well as surface tension of solutions containing different amounts of pullulan and sildenafil was carried out.

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Aligned polymer nanofibres are prepared by means of the electrospinning of a chlorobenzene solution containing regioregular poly(3-hexyltiophene-2,5-diyl), P3HT, and poly(ethylene oxide), PEO. The PEO scaffold is easily dissolved with acetonitrile, leaving pure P3HT fibres, which do not show structural modification. Polymer fibres, either with or without the PEO supporting polymer, are effectively doped by exposure to iodine vapours.

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In this study, we describe a host-guest system consisting of a push-pull dye, the 4-amino-4'-nitroazobenzene (Disperse Orange 3, ), mixed with the copolymer poly(vinylidene fluoride-co-trifluoroethylene) [] as a potential candidate for nonlinear optics (NLO) applications. We developed electrospun nanofibers of the polymer/dye blend, showing a highly anisotropic molecular structure, where molecules are mostly oriented parallel to the polymer chain, running in the fiber axis direction. The technique opens a way for obtaining non-centrosymmetric ordering of the NLO chromophore without requiring further poling.

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Article Synopsis
  • * Researchers explore the thermal changes, especially around the Curie temperature, and the resulting structure after annealing, while identifying spectroscopic markers that relate to molecular structure and orientation.
  • * The combination of experimental data and theoretical calculations helps pinpoint vibrational modes in the copolymer, providing valuable tools for understanding the relationship between structure and the piezoelectric properties of these materials.
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