Copper-Layered Double Hydroxide for Methanol Electrooxidation: A Combined DFT and Experimental Characterization
Anno: 2024
Autori/autrici: Minnelli, C.; Gramigni, D.; Pavoni, E.; Ripani, L.; Laudadio, E.; Mobbili, G.; Barucca, G.; Stipa, P.; Galeazzi, R.; Mengucci, P.; Mohebbi, E.; Romagnoli, E.; Marcaccio, M.
Lingua: ENG
Classificazione IRIS: 4.1 Contributo in Atti di convegno
Scheda completa IRIS: https://iris.univpm.it/handle/11566/336545
Citazioni:
Copper-Layered Double Hydroxide for Methanol Electrooxidation: A Combined DFT and Experimental Characterization / Minnelli, C.; Gramigni, D.; Pavoni, E.; Ripani, L.; Laudadio, E.; Mobbili, G.; Barucca, G.; Stipa, P.; Galeazzi, R.; Mengucci, P.; Mohebbi, E.; Romagnoli, E.; Marcaccio, M.. - (2024), pp. 202-206. (Intervento presentato al convegno 2024 IEEE International Workshop on Metrology for Living Environment, MetroLivEnv 2024 tenutosi a grc nel 2024) [10.1109/MetroLivEnv60384.2024.10615350].
Abstract:
Exposure to volatile organic compounds (VOCs) can cause several health problems both in humans and animals. Among them, methanol (CH3OH), the most abundant oxygenated VOCs present in the troposphere, is a precursor of carbon monoxide (CO) and formaldehyde (CH3CHO) but it is also one of the simplest ...molecules used as a fuel for cleaner energy production. The aim of this research aspires to design and characterize promising advanced functional sensor-material based on CH3OH oxidation to either drive energy conversion, detect the methanol concentration and/or prevent environmental methanol pollution. The electrochemical methanol oxidation reaction (MOR) is a meaningful pathway to obtain these aims since the low potential is required for reaction occurrence. In the context of the development of sustainable and economic sensor-material, layered double hydroxide (LDH) based on Cu is a very promising one. Two different LDH copper-based composites were synthetized and characterized by means of X-ray diffraction experiments, electrochemical measurements, and atomistic simulations. Results showed a crucial structural role played by the type of M(II) ion present in the structure of the LDH. In particular, copper-based LDH containing Zn(II) exhibits a stronger ability to oxidize CH3OH than those containing Mg(II). The atomistic simulations indicate a sort of cooperative affect by the Zn(II), most probably through an enhanced adsorption phenomenon which is relevant in the mediated electron transfer by the active species Cu(III). Overall, this work highlighted the prevision potential of the in silico studies which will be useful to faster screen of different materials followed by selection and synthesis of those showing the optimal features in terms of pollutant adsorption and structure stability. This combined experimental-in silico approach could therefore lead to a faster design and optimization of effective functional materials for applications in indoor and outdoor quality.
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Insights into the interfaces of VO2(M) and VO2(B) polymorphs with different substrates
Anno: 2024
Rivista: MATERIALS ADVANCES
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Laudadio, Emiliano; Mencarelli, Davide
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/327903
Citazioni:
Insights into the interfaces of VO2(M) and VO2(B) polymorphs with different substrates / Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Laudadio, Emiliano; Mencarelli, Davide. - In: MATERIALS ADVANCES. - ISSN 2633-5409. - ELETTRONICO. - 5:8(2024), pp. 3424-3431. [10.1039/d4ma00048j]
Abstract:
The phenomena arising at the interface between oxide materials and substrates can fundamentally and practically change the physical and chemical properties of the materials themselves. In this study, we employed density functional theory (DFT) calculations to elucidate the stability and optical prop...erties of VO2(M) and VO2(B) interactions with substrates of sapphire(c-cut), sapphire(r-cut), SrTiO3(001), SrTiO3(111), SrNbO3(001), SrNbO3(111), LaAlO3(c-cut), and LaAlO3(r-cut). The surface calculations showed that the fully relaxed SrTiO3(111) and SrNbO3(001) possess the highest energies of 31.8 eV nm−2 and 21.15 eV nm−2 relative to other slabs, before optimizing with VO2(M) and VO2(B) polymorphs, respectively. The calculated adsorption energy indicated that the interface of VO2(M) and VO2(B) structures showed more stability on SrTiO3(001) and SrTiO3(111), with adsorption energy values of 2.83 eV and 0.91 eV, respectively. Furthermore, the optical absorption properties of the highest and lowest stable interfaces have been evaluated. The outcomes predicted that VO2(M)@SrTiO3(001) and VO2(B)@SrTiO3(111) have their optical adsorption in the visible light range, while VO2(M)@sapphire(c-cut) and VO2(B)@sapphire(c-cut) showed the main adsorption peak in the infrared region.
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Quantum tunnelling in hafnia-based metal-insulator-metal diodes: atomistic-to-continuum modelling approach and experimental validation
Anno: 2024
Rivista: PHYSICA SCRIPTA
Autori/autrici: Pavoni, Eleonora; Laudadio, Emiliano; Christopher, Hardly Joseph; Zampa, Gian Marco; Russo, Paola; Mohebbi, Elaheh; Mencarelli, Davide; Dragoman, Mircea; Stipa, Pierluigi; Pierantoni, Luca; Aldrigo, Martino
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/326511
Citazioni:
Quantum tunnelling in hafnia-based metal-insulator-metal diodes: atomistic-to-continuum modelling approach and experimental validation / Pavoni, Eleonora; Laudadio, Emiliano; Christopher, Hardly Joseph; Zampa, Gian Marco; Russo, Paola; Mohebbi, Elaheh; Mencarelli, Davide; Dragoman, Mircea; Stipa, Pierluigi; Pierantoni, Luca; Aldrigo, Martino. - In: PHYSICA SCRIPTA. - ISSN 0031-8949. - ELETTRONICO. - 99:2(2024), pp. 025511.1-025511.15. [10.1088/1402-4896/ad1976]
Abstract:
In this work, we present a metal-insulator-metal (MIM) diode, based on quantum tunnelling phenomena. Its model is based on a multilevel modelling approach consisting of atomistic and continuum simulations, fully validated by extensive measurements. The MIM structure comprises a hafnium oxide (or haf...nia, HfO2) dielectric layer, less than 4 nm thick and a square contact area of only 4 μm2, placed between two metallic electrodes, namely platinum as the source and titanium as the drain. The current–voltage (I–V) curve has been estimated by Density Functional Theory (DFT) calculations through an optimisation of the interfaces between metals and monoclinic HfO2. The dielectric parameters arising from ab initio computations have then been used as inputs for the successive circuit and electromagnetic simulations. Finally, the multilevel model has been validated with great accuracy, first measuring the I–V characteristics by applying a drain-source voltage between −1 V and +1 V, and then extracting the scattering parameters up to 40 GHz, thus demonstrating that DFT and circuit/electromagnetic simulations match almost perfectly the experimental ones. These outcomes represent the first study of such nanoscale devices investigated by means of a rigorous atomistic-to-continuum approach, providing invaluable information in order to improve fabrication and correctly assess the macroscale performance of nanoelectronics systems.
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Adsorption of Polylactic-co-Glycolic Acid on Zinc Oxide Systems: A Computational Approach to Describe Surface Phenomena
Anno: 2024
Rivista: NANOMATERIALS
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Minnelli, Cristina; Galeazzi, Roberta; Mobbili, Giovanna; Sabbatini, Simona; Stipa, Pierluigi; Masoud Seyyed Fakhrabadi, Mir; Laudadio, Emiliano
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/329232
Citazioni:
Adsorption of Polylactic-co-Glycolic Acid on Zinc Oxide Systems: A Computational Approach to Describe Surface Phenomena / Mohebbi, Elaheh; Pavoni, Eleonora; Minnelli, Cristina; Galeazzi, Roberta; Mobbili, Giovanna; Sabbatini, Simona; Stipa, Pierluigi; Masoud Seyyed Fakhrabadi, Mir; Laudadio, Emiliano. - In: NANOMATERIALS. - ISSN 2079-4991. - ELETTRONICO. - 14:8(2024). [10.3390/nano14080687]
Abstract:
Zinc oxide and polylactic-co-glycolic acid (ZnO-PLGA) nanocomposites are known to exhibit different biomedical applications and antibacterial activity, which could be beneficial for adding to wound dressings after different surgeries. However, possible cytotoxic effects along with various unexpected... activities could reduce the use of these prominent systems. This is correlated to the property of ZnO, which exhibits different polymeric forms, in particular, wurtzite, zinc-blende, and rocksalt. In this study, we propose a computational approach based on the density functional theory to investigate the properties of ZnO-PLGA systems in detail. First, three different stable polymorphs of ZnO were considered. Subsequently, the abilities of each system to absorb the PLGA copolymer were thoroughly investigated, taking into account the modulation of electrical, optical, and mechanical properties. Significant differences between ZnO and PLGA systems have been found; in this study, we remark on the potential use of these models and the necessity to describe crucial surface aspects that might be challenging to observe with experimental approaches but which can modulate the performance of nanocomposites.
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Towards graphene-based asymmetric diodes: a density functional tight-binding study
Anno: 2024
Rivista: NANOSCALE ADVANCES
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Hemmetter, Andreas; Laudadio, Emiliano; Mencarelli, Davide
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/327579
Citazioni:
Towards graphene-based asymmetric diodes: a density functional tight-binding study / Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Hemmetter, Andreas; Laudadio, Emiliano; Mencarelli, Davide. - In: NANOSCALE ADVANCES. - ISSN 2516-0230. - ELETTRONICO. - 6:5(2024), pp. 1548-1555. [10.1039/D3NA00603D]
Abstract:
Self-consistent charge density functional tight-binding (DFTB) calculations have been performed to investigate the electrical properties and transport behavior of asymmetric graphene devices (AGDs). Three different nanodevices constructed of different necks of 8 nm, 6 nm and 4 nm, named Graphene-N8,... Graphene-N6 and Graphene-N4, respectively, have been proposed. All devices have been tested under two conditions of zero gate voltage and an applied gate voltage of +20 V using a dielectric medium of 3.9 epsilon interposed between the graphene and the metallic gate. As expected, the results of AGD diodes exhibited strong asymmetric I(V) characteristic curves in good agreement with the available experimental data. Our predictions implied that Graphene-N4 would achieve great asymmetry (A) of 1.40 at |VDS| = 0.2 V with maximum transmittance (T) of 6.72 in the energy range 1.30 eV. More importantly, while the A of Graphene-N4 was slightly changed by applying the gate voltage, Graphene-N6/Graphene-N8 showed a significant effect with their A increased from 1.20/1.03 under no gate voltage (NGV) to 1.30/1.16 under gate voltage (WGV) conditions. Our results open up unprecedented numerical prospects for designing tailored geometric diodes.
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Effect of different pseudopotentials on the phonon frequencies, dielectric constant, and Born effective charge of SnSe and SnSe2 nanostructures: A density functional perturbation theory study
Anno: 2024
Rivista: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Laudadio, Emiliano; Mencarelli, Davide
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/324392
Citazioni:
Effect of different pseudopotentials on the phonon frequencies, dielectric constant, and Born effective charge of SnSe and SnSe2 nanostructures: A density functional perturbation theory study / Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Laudadio, Emiliano; Mencarelli, Davide. - In: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS. - ISSN 0022-3697. - ELETTRONICO. - 185:(2024). [10.1016/j.jpcs.2023.111755]
Abstract:
The choice of the pseudopotentials (PPs) is a crucial step towards an accurate atomistic calculation of physical properties of 2D materials. In this study, based on Density-Functional Perturbation Theory (DFPT), we investigated the dependency of the phonon properties such as phonon frequencies, diel...ectric constant, Born effective charge, and vibrational modes of SnSe and SnSe2 monolayers to the different types of PPs. On the basis of Generalized Gradient Approximation (GGA) using PBE functional, we computed eight phonon calculations for both lattices in combinations with four different PPs including Normconversing (NC) FHI/HGH, Ultrasoft (USPP), and Standard Solid-State (SSSP), while other parameters like cut-off energy, k-points mesh, and convergence threshold were kept fixed. However, the phonon properties of acoustic and optical phonons were better predicted by USPP and SSSP for phonon dispersion of SnSe and SnSe2, respectively. Regarding the dielectric constant and Bohr effective charge calculations, our results showed that SnSe and SnSe2 structures possess the dielectric tensor of 8.9 and 6.6 along the in-plane direction by using USPP calculations. Our outcomes also revealed less sensitivity of SnSe2 polarization to the type of PPs by applying the electric field. This study recommends USPP and SSSP to further phonon analysis of other semiconductors.
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Band gap and THz optical adsorption of SnSe and SnSe2 nanosheets on graphene: Negative dielectric constant of SnSe
Anno: 2024
Rivista: RESULTS IN PHYSICS
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Zampa, Gian Marco; Laudadio, Emiliano; Mencarelli, Davide
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/326952
Citazioni:
Band gap and THz optical adsorption of SnSe and SnSe2 nanosheets on graphene: Negative dielectric constant of SnSe / Mohebbi, Elaheh; Pavoni, Eleonora; Pierantoni, Luca; Stipa, Pierluigi; Zampa, Gian Marco; Laudadio, Emiliano; Mencarelli, Davide. - In: RESULTS IN PHYSICS. - ISSN 2211-3797. - ELETTRONICO. - 57:(2024). [10.1016/j.rinp.2024.107415]
Abstract:
Density functional theory (DFT) calculations have been used to investigate physical–chemical sensing of various proposed interfaces as SnSe@Graphene, SnSe2@Graphene, Graphene@SnSe@Graphene, and Graphene@SnSe2@Graphene, where dispersion corrections have been included to taken into account the vdW i...nteractions between the layers. Initially, we predicted the electronic structures, mobility and carrier concentrations (cc) of SnSe and SnSe2 structures. Using different methodology, the outcomes have confirmed the semiconductor properties of SnSe and SnSe2 with indirect bandgap of 1.20 eV and 0.94 eV calculated by Generalized Gradient Approximation (GGA) and MetaGGA (MGGA) adopted with Perdew-Burke-Ernzerhof (PBE) functional, while hybrid Heyd-Scuseria-Ernzerhof (HSE) hybrid functional overestimated the experimental observations for both materials. Room temperature high mobility and cc have predicted by 126 × 103 cm2V−1 s−1 with cc of 1.3 × 1013 cm3 for a two layers SnSe and 69 × 103 cm2V−1 s−1 with cc of 4.2 × 1018 cm3 for three layers SnSe2. Optical absorption spectrum revealed that the presence of two peaks at 60 THz and 48 THz with the intensity of 89879 cm−1 and 34504 cm−1 for interfaces including two layers of graphene. More interestingly, dielectric constant calculations showed that the transfer of carriers between graphene layers and SnSe in Graphene@SnSe@Graphene interface with absorption peak shifted to 24 THz along the in-plane direction and negative dielectric constants in the range of 24–169 THz, showing the effect of light-trapping through plasmonic.
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Layered Double Hydroxides as Systems for Capturing Small-Molecule Air Pollutants: A Density Functional Theory Study
Anno: 2024
Rivista: MOLECULES
Autori/autrici: Mohebbi, Elaheh; Minnelli, Cristina; Pavoni, Eleonora; Sisti, Laura; Laudadio, Emiliano; Stipa, Pierluigi
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/337260
Citazioni:
Layered Double Hydroxides as Systems for Capturing Small-Molecule Air Pollutants: A Density Functional Theory Study / Mohebbi, Elaheh; Minnelli, Cristina; Pavoni, Eleonora; Sisti, Laura; Laudadio, Emiliano; Stipa, Pierluigi. - In: MOLECULES. - ISSN 1420-3049. - ELETTRONICO. - 29:21(2024). [10.3390/molecules29214996]
Abstract:
Air pollutants are usually formed by easily spreading small molecules, representing a severe problem for human health, especially in urban centers. Despite the efforts to stem their diffusion, many diseases are still associated with exposure to these molecules. The present study focuses on modeling ...and designing two-dimensional systems called Layered Double Hydroxides (LDHs), which can potentially trap these molecules. For this purpose, a Density Functional Theory (DFT) approach has been used to study the role of the elemental composition of LDHs, the type of counterion, and the ability of these systems to intercalate NO2 and SO2 between the LDH layers. The results demonstrated how the counterion determines the different possible spacing between the layers, modulating the internalization capacity of pollutants and determining the stability degree of the system for a long-lasting effect. The variations in structural properties, the density of states (DOS), and the description of the charge transfer have been reported, thus allowing the investigation of aspects that are difficult to observe from an experimental point of view and, at the same time, providing essential details for the effective development of systems that can counteract the spread of air pollutants
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Unveiling pyroelectricity in ferroelectric planar capacitors with area-selective wet etched hafnium zirconium oxide: from ab initio and multiphysics simulations to experiments
Anno: 2024
Rivista: JPHYS ENERGY
Autori/autrici: Aldrigo, Martino; Zampa, Gian Marco; Dragoman, Mircea; Dinu, Livia Alexandra; Nastase, Florin; Romanitan, Cosmin; Parvulescu, Catalin; Brincoveanu, Oana; Iordanescu, Sergiu; Vulpe, Silviu; Laudadio, Emiliano; Mohebbi, Elaheh; Pavoni, Eleonora
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/337262
Citazioni:
Unveiling pyroelectricity in ferroelectric planar capacitors with area-selective wet etched hafnium zirconium oxide: from ab initio and multiphysics simulations to experiments / Aldrigo, Martino; Zampa, Gian Marco; Dragoman, Mircea; Dinu, Livia Alexandra; Nastase, Florin; Romanitan, Cosmin; Parvulescu, Catalin; Brincoveanu, Oana; Iordanescu, Sergiu; Vulpe, Silviu; Laudadio, Emiliano; Mohebbi, Elaheh; Pavoni, Eleonora. - In: JPHYS ENERGY. - ISSN 2515-7655. - ELETTRONICO. - 6:4(2024). [10.1088/2515-7655/ad8aec]
Abstract:
In this work, a systematic approach aimed at investigating and validating a novel way of realizing pyroelectric harvesting is presented. Generating a direct-current (dc) signal through a temperature gradient within a less than 7 nm-thick ferroelectric zirconium-doped hafnium oxide (HZO) nano-film, e...mbedded in planar interdigitated capacitors on high-resistivity silicon, is a new, simple, effective, and reproducible solution. Temperature-related structural modifications in HZO are first simulated using advanced ab initio calculations. Then, rigorous multiphysics simulations of the final devices provide insight into the expected performance of the pyroelectric harvester, as a function of temperature, contact area, and crystal orientation, showing a maximum open-circuit voltage of up to 900 mV. The fabrication of the harvesters involves the area-selective wet etching of the HZO layer to retain it exclusively in between the fingers of each capacitor. This choice maximizes the pyroelectric effect (which strongly depends on the area) and represents a new paradigm in the development of HZO-based electronics, which are conventionally built on ferroelectric continuous films. Experimental validation at both low frequencies and microwaves confirms the pyroelectric effect, exhibiting a significant increase in the output current for higher temperature gradients, and a generated dc voltage of several hundred millivolts.
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Graphene Monolayer Nanomesh Structures and Their Applications in Electromagnetic Energy Harvesting for Solving the Matching Conundrum of Rectennas
Anno: 2024
Rivista: NANOMATERIALS
Autori/autrici: Dragoman, Mircea; Dinescu, Adrian; Aldrigo, Martino; Dragoman, Daniela; Mohebbi, Elaheh; Pavoni, Eleonora; Laudadio, Emiliano
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/337261
Citazioni:
Graphene Monolayer Nanomesh Structures and Their Applications in Electromagnetic Energy Harvesting for Solving the Matching Conundrum of Rectennas / Dragoman, Mircea; Dinescu, Adrian; Aldrigo, Martino; Dragoman, Daniela; Mohebbi, Elaheh; Pavoni, Eleonora; Laudadio, Emiliano. - In: NANOMATERIALS. - ISSN 2079-4991. - ELETTRONICO. - 14:19(2024). [10.3390/nano14191542]
Abstract:
In this paper, we investigate various graphene monolayer nanomesh structures (diodes) formed only by nanoholes, with a diameter of just 20 nm and etched from the graphene layer in different shapes (such as rhombus, bow tie, rectangle, trapezoid, and triangle), and their electrical properties targeti...ng electromagnetic energy harvesting applications. In this respect, the main parameters characterizing any nonlinear device for energy harvesting are extracted from tens of measurements performed on a single chip containing the fabricated diodes. The best nano-perforated graphene structure is the triangle nanomesh structure, which exhibits remarkable performance in terms of its characteristic parameters, e.g., a 420 Ω differential resistance for optimal impedance matching to an antenna, a high responsivity greater than 103 V/W, and a low noise equivalent power of 847 pW/√Hz at 0 V.
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First principles study of WSe2 and the effect of V doping on the optical and electronic properties
Anno: 2024
Rivista: MATERIALS ADVANCES
Autori/autrici: Pavoni, E.; Mohebbi, E.; Zampa, G. M.; Stipa, P.; Pierantoni, L.; Laudadio, E.; Mencarelli, D.
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/325661
Citazioni:
First principles study of WSe2 and the effect of V doping on the optical and electronic properties / Pavoni, E.; Mohebbi, E.; Zampa, G. M.; Stipa, P.; Pierantoni, L.; Laudadio, E.; Mencarelli, D.. - In: MATERIALS ADVANCES. - ISSN 2633-5409. - (2024). [10.1039/d3ma00940h]
Abstract:
Tungsten diselenide WSe2 is a material with an intriguing character that has captivated the attention of researchers; in this study, an ab initio analysis is presented that focuses on the optical and electronic properties of WSe2. The study made use of density functional theory (DFT) by employing th...e Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) density functional and PseudoDojo pseudopotential. The study looked at the properties of both bulk and monolayer WSe2 to determine how the number of layers affects the properties of the material. To further investigate the properties of WSe2, four different systems based on vanadium doped-WSe2 were analyzed from the optical and electronic points of view. The systems contained different percentages of V: (i) WSe2:V 1.4%, (ii) WSe2:V 2.8%, (iii) WSe2:V 5.6%, and (iv) WSe2:V 11.2%. The introduction of vanadium brought about a reduction of the bandgap and a global shift of the projected density of states. The valence band maximum (VBM) also crossed the Fermi level, which is consistent with the p-type nature of vanadium doping. Furthermore, the absorption spectra changed in terms of the position and the intensity of the optical transition as a result of vanadium introduction.
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Harvesting microwave energy using pyroelectricity of nanostructured graphene/zirconium-doped hafnium oxide ferroelectric heterostructures
Anno: 2023
Rivista: NANOTECHNOLOGY
Autori/autrici: Dragoman, Mircea; Aldrigo, Martino; Dinescu, Adrian; Vasilache, Dan; Iordanescu, Sergiu; Dragoman, Daniela; Laudadio, Emiliano; Pavoni, Eleonora
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/312968
Citazioni:
Harvesting microwave energy using pyroelectricity of nanostructured graphene/zirconium-doped hafnium oxide ferroelectric heterostructures / Dragoman, Mircea; Aldrigo, Martino; Dinescu, Adrian; Vasilache, Dan; Iordanescu, Sergiu; Dragoman, Daniela; Laudadio, Emiliano; Pavoni, Eleonora. - In: NANOTECHNOLOGY. - ISSN 1361-6528. - ELETTRONICO. - 34:20(2023), pp. 1-21. [10.1088/1361-6528/acbcd9]
Abstract:
In this work, we present the design, atomistic/circuit/electromagnetic simulations, and the experimental results for graphene monolayer/zirconium-doped hafnium oxide (HfZrO) ultra-thin ferroelectric-based field effect transistors fabricated at the wafer scale, regarding the pyroelectricity generatio...n directly from microwave signals, at room temperature and below it, namely at 218 K and at 100 K. The transistors work like energy harvesters, i.e. they collect low-power microwave energy and transform it into DC voltages with a maximum amplitude between 20 and 30 mV. The same devices function as microwave detectors in the band 1-10.4 GHz and at very low input power levels not exceeding 80μW when they are biased by using a drain voltage, with average responsivity values in the range 200-400 mV mW-1.
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Stability, phonon calculations, electronic structure, and optical properties of a VO2(M) nanostructure: A comprehensive density functional theory study
Anno: 2023
Rivista: FRONTIERS IN MATERIALS
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Mencarelli, Davide; Stipa, Pierluigi; Laudadio, Emiliano; Pierantoni, Luca
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/312967
Citazioni:
Stability, phonon calculations, electronic structure, and optical properties of a VO2(M) nanostructure: A comprehensive density functional theory study / Mohebbi, Elaheh; Pavoni, Eleonora; Mencarelli, Davide; Stipa, Pierluigi; Laudadio, Emiliano; Pierantoni, Luca. - In: FRONTIERS IN MATERIALS. - ISSN 2296-8016. - ELETTRONICO. - 10:(2023). [10.3389/fmats.2023.1145822]
Abstract:
This work aimed to precisely evaluate the physical properties of vanadium dioxide (M), particularly the optical characteristics. We employed different exchangecorrelation functionals to determine the phase stability, band gap properties, and optical characteristics of an experimentally recognized mo...noclinic VO2(M) polymorph. The calculations not only correctly interpreted the VO2(M) origin but also predicted other optical properties including the extinction coefficient (k) and refractive index (n), which have not been reported in experimental measurements. Phonon dispersion calculations confirmed the presence of negative frequencies for acoustic modes in the phononic curves. When the HSE functional correctly reproduced the experimental band gap, here for the first time, our calculations based on PBE and PBEsol yielded non-zero electronic bandgaps of 0.23 and 0.15 eV for bulk VO2(M). Our predictions showed that semilocal functionals can adequately predict the semiconductor properties of VO2(M) and performed better than all previously reported theoretical works on nulled band gaps. In addition to the better prediction of the peak position in the absorption spectra with HSE hybrid functional, this method also reasonably well described the static dielectric constant of 7.54, showing an excellent match to the experimental values. In general, the results of this study reveal that hybrid functionals yield superior outcomes compared to semi-local functionals for optical properties of a VO2(M) polymorph. Our results suggest that the PBEsol + HSE approach allows the efficient characterization of smart materials for electronic and optoelectronic applications.
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SARS-CoV-2 multi-variant rapid detector based on graphene transistor functionalized with an engineered dimeric ACE2 receptor
Anno: 2023
Rivista: NANO TODAY
Autori/autrici: Romagnoli, A.; D'Agostino, M.; Pavoni, E.; Ardiccioni, C.; Motta, S.; Crippa, P.; Biagetti, G.; Notarstefano, V.; Rexha, J.; Perta, N.; Barocci, S.; Costabile, B. K.; Colasurdo, G.; Caucci, S.; Mencarelli, D.; Turchetti, C.; Farina, M.; Pierantoni, L.; La Teana, A.; Al Hadi, R.; Cicconardi, F.; Chinappi, M.; Trucchi, E.; Mancia, F.; Menzo, S.; Morozzo della Rocca, B.; D'Annessa, I.; Di Marino, D.
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/309546
Citazioni:
SARS-CoV-2 multi-variant rapid detector based on graphene transistor functionalized with an engineered dimeric ACE2 receptor / Romagnoli, A.; D'Agostino, M.; Pavoni, E.; Ardiccioni, C.; Motta, S.; Crippa, P.; Biagetti, G.; Notarstefano, V.; Rexha, J.; Perta, N.; Barocci, S.; Costabile, B. K.; Colasurdo, G.; Caucci, S.; Mencarelli, D.; Turchetti, C.; Farina, M.; Pierantoni, L.; La Teana, A.; Al Hadi, R.; Cicconardi, F.; Chinappi, M.; Trucchi, E.; Mancia, F.; Menzo, S.; Morozzo della Rocca, B.; D'Annessa, I.; Di Marino, D.. - In: NANO TODAY. - ISSN 1748-0132. - 48:(2023). [10.1016/j.nantod.2022.101729]
Abstract:
Reliable point-of-care (POC) rapid tests are crucial to detect infection and contain the spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The emergence of several variants of concern (VOC) can reduce binding affinity to diagnostic antibodies, limiting the efficacy of the curre...ntly adopted tests, while showing unaltered or increased affinity for the host receptor, angiotensin converting enzyme 2 (ACE2). We present a graphene field-effect transistor (gFET) biosensor design, which exploits the Spike-ACE2 interaction, the crucial step for SARS-CoV-2 infection. Extensive computational analyses show that a chimeric ACE2-Fragment crystallizable (ACE2-Fc) construct mimics the native receptor dimeric conformation. ACE2-Fc functionalized gFET allows in vitro detection of the trimeric Spike protein, outperforming functionalization with a diagnostic antibody or with the soluble ACE2 portion, resulting in a sensitivity of 20 pg/mL. Our miniaturized POC biosensor successfully detects B.1.610 (pre-VOC), Alpha, Beta, Gamma, Delta, Omicron (i.e., BA.1, BA.2, BA.4, BA.5, BA.2.75 and BQ.1) variants in isolated viruses and patient's clinical nasopharyngeal swabs. The biosensor reached a Limit Of Detection (LOD) of 65 cps/mL in swab specimens of Omicron BA.5. Our approach paves the way for a new and reusable class of highly sensitive, rapid and variant-robust SARS-CoV-2 detection systems.
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First-principles investigation of interface phenomena in hafnium-based metal–insulator–metal diodes
Anno: 2023
Rivista: NANOSCALE ADVANCES
Autori/autrici: Pavoni, Eleonora; Mohebbi, Elaheh; Stipa, Pierluigi; Pierantoni, Luca; Mencarelli, Davide; Dragoman, Mircea; Aldrigo, Martino; Laudadio, Emiliano
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/313853
Citazioni:
First-principles investigation of interface phenomena in hafnium-based metal–insulator–metal diodes / Pavoni, Eleonora; Mohebbi, Elaheh; Stipa, Pierluigi; Pierantoni, Luca; Mencarelli, Davide; Dragoman, Mircea; Aldrigo, Martino; Laudadio, Emiliano. - In: NANOSCALE ADVANCES. - ISSN 2516-0230. - ELETTRONICO. - 5:10(2023), pp. 2748-2755. [10.1039/d2na00739h]
Abstract:
Metal–insulator–metal (MIM) diodes are very interesting in many different applications exploiting environment-friendly renewable energy solutions. Moreover, since the dimensions of such devices are at the nanoscale, the size and the characteristics of their constitutive elements can drastically ...influence their macroscale performance. As it could be difficult to describe in detail the physical phenomena occurring among materials in nanoscale systems, in this work first-principles calculations have been used to study the structural and electrical properties of three different hafnium oxide (HfO2)-MIM diodes. These devices have been simulated at the atomistic level by interposing 3 nm of HfO2 between drain and source electrodes made of gold and platinum, respectively. The monoclinic and orthorhombic polymorphs of HfO2 have been considered to model different types of MIM diodes, and the interface geometries have been optimized to compute the current–voltage characteristics, reflecting the tunneling mechanisms occurring in such devices. The calculation of the transmission pathways has also been carried out to investigate the effects of atomistic coordinates despite the use of the same material. The results demonstrate the role of the Miller indices of metals and the influence of the HfO2 polymorphs on the MIM properties. In this study, the importance of interface phenomena on the measurable properties of the proposed devices has been investigated in detail.
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Insights Into a New Geometric Graphene Diode with Ultrahigh Asymmetry Ratio: A Computational Approach
Anno: 2023
Rivista: PROCEEDINGS OF THE ... IEEE CONFERENCE ON NANOTECHNOLOGY
Autori/autrici: Mohebbi, E.; Pavoni, E.; Pierantoni, L.; Stipa, P.; Laudadio, E.; Mencarelli, D.
Lingua: ENG
Classificazione IRIS: 4.1 Contributo in Atti di convegno
Scheda completa IRIS: https://iris.univpm.it/handle/11566/326753
Citazioni:
Insights Into a New Geometric Graphene Diode with Ultrahigh Asymmetry Ratio: A Computational Approach / Mohebbi, E.; Pavoni, E.; Pierantoni, L.; Stipa, P.; Laudadio, E.; Mencarelli, D.. - In: PROCEEDINGS OF THE ... IEEE CONFERENCE ON NANOTECHNOLOGY. - ISSN 1944-9399. - 2023-:(2023), pp. 238-242. (Intervento presentato al convegno 23rd IEEE International Conference on Nanotechnology, NANO 2023 tenutosi a kor nel 2023) [10.1109/NANO58406.2023.10231305].
Abstract:
In this study, we introduce a novel concept of the transport properties of three proposed geometric graphene diodes based on self-consistent charge density functional tight-binding method. The calculations have been performed with bias voltages up to a few volts suitable for electronics applications.... Geometrical graphene devices based ballistic region exhibited strong nonlinear I(V) characteristic curves as well as desirable current amounts. The results indicated that the graphene Device C with an edge width 5nm and angle of 47° showed an excellent current value of 213 μA at 1.5V, which was higher than other two devices A and B with edge widths 9 nm and 5nm and corresponding angle 61°. A maximum AR of 2.23 has been achieved at a current of 137 μA for Device C, which is among the highest values for a geometric graphene device reported to date. This study provides a pathway for optimizing the graphene diodes to be used as potential applications for energy harvesting devices.
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First-Principles Calculation of MoO2 and MoO3 Electronic and Optical Properties Compared with Experimental Data
Anno: 2023
Rivista: NANOMATERIALS
Autori/autrici: Pavoni, Eleonora; Modreanu, MIRCEA GABRIEL; Mohebbi, Elaheh; Mencarelli, Davide; Stipa, Pierluigi; Laudadio, Emiliano; Pierantoni, Luca
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/314849
Citazioni:
First-Principles Calculation of MoO2 and MoO3 Electronic and Optical Properties Compared with Experimental Data / Pavoni, Eleonora; Modreanu, MIRCEA GABRIEL; Mohebbi, Elaheh; Mencarelli, Davide; Stipa, Pierluigi; Laudadio, Emiliano; Pierantoni, Luca. - In: NANOMATERIALS. - ISSN 2079-4991. - ELETTRONICO. - 13:8(2023). [10.3390/nano13081319]
Abstract:
MoO3 and MoO2 systems have attracted particular attention for many widespread applications thanks to their electronic and optical peculiarities; from the crystallographic point of view, MoO3 adopts a thermodynamically stable orthorhombic phase (α-MoO3) belonging to the space group Pbmn, while MoO2 ...assumes a monoclinic arrangement characterized by space group P21/c. In the present paper, we investigated the electronic and optical properties of both MoO3 and MoO2 by using Density Functional Theory calculations, in particular, the Meta Generalized Gradient Approximation (MGGA) SCAN functional together with the PseudoDojo pseudopotential, which were used for the first time to obtain a deeper insight into the nature of different Mo–O bonds in these materials. The calculated density of states, the band gap, and the band structure were confirmed and validated by comparison with already available experimental results, while the optical properties were validated by recording optical spectra. Furthermore, the calculated band-gap energy value for the orthorhombic MoO3 showed the best match to the experimental value reported in the literature. All these findings suggest that the newly proposed theoretical techniques reproduce the experimental evidence of both MoO2 and MoO3 systems with high accuracy.
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Density functional theory and molecular dynamics studies on electrical, mechanical, and thermal properties of TiO2 nanoparticles interacting with poly lactic-co-glycolic acid
Anno: 2023
Rivista: COLLOIDS AND SURFACES. A, PHYSICOCHEMICAL AND ENGINEERING ASPECTS
Autori/autrici: Laudadio, Emiliano; Mohebbi, Elaheh; Pavoni, Eleonora; Minnelli, Cristina; Sabbatini, Simona; Stipa, Pierluigi
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/313852
Citazioni:
Density functional theory and molecular dynamics studies on electrical, mechanical, and thermal properties of TiO2 nanoparticles interacting with poly lactic-co-glycolic acid / Laudadio, Emiliano; Mohebbi, Elaheh; Pavoni, Eleonora; Minnelli, Cristina; Sabbatini, Simona; Stipa, Pierluigi. - In: COLLOIDS AND SURFACES. A, PHYSICOCHEMICAL AND ENGINEERING ASPECTS. - ISSN 0927-7757. - ELETTRONICO. - 667:(2023), pp. 1-10. [10.1016/j.colsurfa.2023.131388]
Abstract:
Poly-lactic poly-co-glycolic acid (PLGA) copolymer is widely used thanks to its biocompatibility, even if could be difficult to find desirable mechanical properties for the polymer matrix. For this reason, inorganic nanoparticles like titanium dioxide (TiO2) can be used to modulate the mechanical ...properties of systems maintaining their biological capabilities. In this concern, density functional theory (DFT) and molecular dynamics (MD) simulations have been used to study the absorption phenomena of PLGA on surfaces of I4₁/amd (Anatase), P42/mnm (Rutile), and Pbca (Brookite) polymorphs of TiO2 DFT results showed that Anatase TiO2 is the best choice to absorb PLGA in comparison to the other PLGA-TiO2 surfaces. MD simulations remarked a peculiar stabilization pathway of PLGA-TiO2 with Anatase surface along the MD time and the largest increase in both Young’s and Bulk’s moduli. Finally, the influence of temperature on the mechanical properties of PLGA/A-TiO2 has also been investigated; in particular, MD results revealed that Young’s modulus of nanocomposite and the binding energy decreased by increasing the temperature. The outcomes of the present investigation could be helpful to clarify the potential uses of the PLGA-TiO2 nanocomposites in the biomedical field ranging from bone tissue engineering to drug delivery.
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Inverted Scanning Microwave Microscopy
Anno: 2022
Rivista: GIT IMAGING & MICROSCOPY
Autori/autrici: Azman, SITI NUR AFIFA BINTI; Pavoni, Eleonora; Farina, Marco
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/309979
Citazioni:
Inverted Scanning Microwave Microscopy / Azman, SITI NUR AFIFA BINTI; Pavoni, Eleonora; Farina, Marco. - In: GIT IMAGING & MICROSCOPY. - ISSN 1439-4243. - 24:(2022), pp. 14-16.
Abstract:
Scanning Microwave Microscopy (SMM) is prominent for providing imaging of sub-surface structures and allowing local quantitative characterization of the sample. A novel technique known as Inverted Scanning Microwave Microscopy (iSMM) is the improvement developed recently to broaden the application ...beyond the current focus on surface physics and semiconductor technology. With a simple metal probe, the iSMM can be converted from existing atomic force microscopes (AFM) or scanning tunneling microscopes (STM) outperforming the conventional SMM in terms of bandwidth, sensitivity, and dynamic range. The iSMM was primarily used to analyze biological samples as it can operate in liquid
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Nanoscale Characterization of Graphene Oxide-Based Epoxy Nanocomposite Using Inverted Scanning Microwave Microscopy
Anno: 2022
Rivista: SENSORS
Autori/autrici: Joseph, C. H.; Luzi, Francesca; Azman, S. N. Afifa; Forcellese, Pietro; Pavoni, Eleonora; Fabi, Gianluca; Mencarelli, Davide; Gentili, Serena; Pierantoni, Luca; Morini, Antonio; Simoncini, Michela; Bellezze, Tiziano; Corinaldesi, Valeria; Farina, Marco
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/309543
Citazioni:
Nanoscale Characterization of Graphene Oxide-Based Epoxy Nanocomposite Using Inverted Scanning Microwave Microscopy / Joseph, C. H.; Luzi, Francesca; Azman, S. N. Afifa; Forcellese, Pietro; Pavoni, Eleonora; Fabi, Gianluca; Mencarelli, Davide; Gentili, Serena; Pierantoni, Luca; Morini, Antonio; Simoncini, Michela; Bellezze, Tiziano; Corinaldesi, Valeria; Farina, Marco. - In: SENSORS. - ISSN 1424-8220. - ELETTRONICO. - 22:24(2022). [10.3390/s22249608]
Abstract:
Scanning microwave microscopy (SMM) is a novel metrological tool that advances the quantitative, nanometric, high-frequency, electrical characterization of a broad range of materials of technological importance. In this work, we report an inverted near-field scanning microwave microscopy (iSMM) inve...stigation of a graphene oxide-based epoxy nanocomposite material at a nanoscopic level. The high-resolution spatial mapping of local conductance provides a quantitative analysis of the sample's electrical properties. In particular, the electrical conductivity in the order of ∼10-1 S/m as well as the mapping of the dielectric constant with a value of ∼4.7 ± 0.2 are reported and validated by the full-wave electromagnetic modeling of the tip-sample interaction.
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The Effect of Y Doping on Monoclinic, Orthorhombic, and Cubic Polymorphs of HfO2: A First Principles Study
Anno: 2022
Rivista: NANOMATERIALS
Autori/autrici: Pavoni, Eleonora; Mohebbi, Elaheh; Mencarelli, Davide; Stipa, Pierluigi; Laudadio, Emiliano; Pierantoni, Luca
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/309301
Citazioni:
The Effect of Y Doping on Monoclinic, Orthorhombic, and Cubic Polymorphs of HfO2: A First Principles Study / Pavoni, Eleonora; Mohebbi, Elaheh; Mencarelli, Davide; Stipa, Pierluigi; Laudadio, Emiliano; Pierantoni, Luca. - In: NANOMATERIALS. - ISSN 2079-4991. - ELETTRONICO. - 12:23(2022). [10.3390/nano12234324]
Abstract:
HfO2 can assume different crystalline structures, such as monoclinic, orthorhombic, and cubic polymorphs, each one characterized by unical properties. The peculiarities of this material are also strongly related to the presence of doping elements in the unit cell. Thus, the present paper has the mai...n purpose of studying and comparing twelve different systems characterized by diverse polymorphs and doping percentages. In particular, three different crystalline structures were considered: the monoclinic P21/c, the orthorhombic Pca21, and the cubic Fm3¯m phases of HfO2. Each one has been studied by using Y as a doping agent with three different contents: 0% Y:HfO2, 8% Y:HfO2, 12% Y:HfO2, and 16% Y:HfO2. For all the systems, density functional theory (DFT) methods based on PBE/GGA, and on the HSE hybrid functionals were used to optimize the geometry as well as to study their optical properties. Depending on the polymorphs, Y affects the formation energy in different ways and causes changes in the optical properties. When the percentage of Y did not exceed 12%, a stabilization of the cubic phase fraction and an increase of the dielectric constant was observed. Additionally, the calculated optical bandgap energies and the refractive index are examined to provide an overview of the systems and are compared with experimental data. The bandgaps obtained are in perfect agreement with the experimental values and show a slight increase as the doping percentage grows, while only minor differences are found between the three polymorphs in terms of both refractive index and optical band gap. The adopted first principles study generates a reasonable prediction of the physical-chemical properties of all the systems, thus identifying the effects of doping phenomena.
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The Role of Zr on Monoclinic and Orthorhombic HfxZryO2 Systems: A First-Principles Study
Anno: 2022
Rivista: MATERIALS
Autori/autrici: Pavoni, Eleonora; Mohebbi, Elaheh; Stipa, Pierluigi; Mencarelli, Davide; Pierantoni, Luca; Laudadio, Emiliano
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/303736
Citazioni:
The Role of Zr on Monoclinic and Orthorhombic HfxZryO2 Systems: A First-Principles Study / Pavoni, Eleonora; Mohebbi, Elaheh; Stipa, Pierluigi; Mencarelli, Davide; Pierantoni, Luca; Laudadio, Emiliano. - In: MATERIALS. - ISSN 1996-1944. - STAMPA. - 15:12(2022). [10.3390/ma15124175]
Abstract:
HfO2 shows different polymorphs, including monoclinic and orthorhombic ones, that exhibit singular properties. Moreover, the character of HfO2 is also influenced by the Zr atoms as a doping agent. Here, an extensive study of the monoclinic P21/c and the orthorhombic Pca21 polymorphs of HfO2, Hf0.75Z...r0.25O2, and Hf0.5Zr0.5O2 is reported. For all six systems, density functional theory (DFT) methods based on generalized gradient approximations (GGAs) were first used; then the GGA + U method was settled and calibrated to describe the electrical and optical properties of polymorphs and the responses to the oxygen vacancies. Zr had different effects in relation to the polymorph; moreover, the amount of Zr led to important differences in the optical properties of the Pca21 polymorph. Finally, oxygen vacancies were investigated, showing an important modulation of the properties of HfxZryO2 nanostructures. The combined GGA and GGA + U methods adopted in this work generate a reasonable prediction of the physicochemical properties of o- and m-HfxZryO2, identifying the effects of doping phenomena.
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Inverted Scanning Microwave Microscopy of a Vital Mitochondrion in Liquid
Anno: 2022
Rivista: IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
Autori/autrici: Azman, S. N. Afifa; Fabi, Gianluca; Pavoni, Eleonora; Joseph, C. H.; Pini, Niccolo; Pietrangelo, Tiziana; Pierantoni, Luca; Morini, Antonio; Mencarelli, Davide; Di Donato, Andrea; Hwang, James C. M.; Farina, Marco
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/297861
Citazioni:
Inverted Scanning Microwave Microscopy of a Vital Mitochondrion in Liquid / Azman, S. N. Afifa; Fabi, Gianluca; Pavoni, Eleonora; Joseph, C. H.; Pini, Niccolo; Pietrangelo, Tiziana; Pierantoni, Luca; Morini, Antonio; Mencarelli, Davide; Di Donato, Andrea; Hwang, James C. M.; Farina, Marco. - In: IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS. - ISSN 1531-1309. - 32:6(2022), pp. 804-806. [10.1109/LMWC.2022.3160694]
Abstract:
The inverted scanning microwave microscope (iSMM) is a recently developed variety of scanning microprobe microscopes. Similar to an SMM, the iSMM is sensitive to not only surface structure, but also electromagnetic properties below the surface. Different from the SMM, the iSMM can be converted from ...any scanning probe microscope, such as an atomic force microscope (AFM) and a scanning tunneling microscope, with a simple metal probe to outperform the SMM in terms of ruggedness, bandwidth, sensitivity, and dynamic range. This paper reports the first iSMM images of a vital mitochondrion in an isotonic glucose solution. Compared to the AFM and SMM, the iSMM offers more insights into the mitochondrion. This shows the potential of iSMM for noninvasive and label-free imaging and characterization of subcellular structures.
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Insights into first-principles characterization of the monoclinic VO2(B) polymorph via DFT + U calculation: electronic, magnetic and optical properties
Anno: 2022
Rivista: NANOSCALE ADVANCES
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Mencarelli, Davide; Stipa, Pierluigi; Pierantoni, Luca; Laudadio, Emiliano
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/306543
Citazioni:
Insights into first-principles characterization of the monoclinic VO2(B) polymorph via DFT + U calculation: electronic, magnetic and optical properties / Mohebbi, Elaheh; Pavoni, Eleonora; Mencarelli, Davide; Stipa, Pierluigi; Pierantoni, Luca; Laudadio, Emiliano. - In: NANOSCALE ADVANCES. - ISSN 2516-0230. - ELETTRONICO. - 4:17(2022), pp. 3634-3646. [10.1039/D2NA00247G]
Abstract:
We have studied the structural, electronic, magnetic, and optical properties of the VO2(B) polymorph using first-principles calculations based on density functional theory (DFT). This polymorph was found to display four optimized structures namely VO2(B)PP, VO2(B)LP, VO2(B)PPD, and VO2(B)LPD using t...he generalized gradient approximation (GGA) PBE exchange-correlation functional by including/excluding van der Waals interaction. Our derivation provides a theoretical justification for adding an on-site Coulomb U value in the conventional DFT calculations to allow a direct comparison of the two methods. We predicted a zero bandgap of the VO2(B) structure based on GGA/PBE. However, by GGA/PBE + U, we found accurate bandgap values of 0.76, 0.66, and 0.70 eV for VO2(B)PP, VO2(B)LP, and VO2(B)PPD, respectively. The results obtained from DFT + U were accompanied by a structural transition from the metallic to semiconductor property. Here, we verified the non-magnetic characteristic of the monoclinic VO2(B) phase with some available experimental and theoretical data. However, the debate on the magnetic property of this polymorph remains unresolved. Imaginary and real parts of the dielectric function, as computed with the GGA/PBE functional and the GGA/PBE + U functional, were also reported. The first absorption peaks of all considered geometries in the imaginary part of the dielectric constants indicated that the VO2(B) structure could perfectly absorb infrared light. The computed static dielectric constants with positive values, as derived from the optical properties, confirmed the conductivity of this material. Among the four proposed geometries of VO2(B) in this study, the outcomes obtained by VO2(B)PPD reveal good results owing to the excellent consistency of its bandgap, magnetic and optical properties with other experimental and theoretical observations. The theoretical framework in our study will provide useful insight for future practical applications of the VO2(B) polymorph in electronics and optoelectronics.
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PBEsol/HSE Functional: A promising candidate for Vanadium dioxide (B) characterization
Anno: 2022
Rivista: RSC ADVANCES
Autori/autrici: Mohebbi, Elaheh; Pavoni, Eleonora; Mencarelli, Davide; Stipa, Pierluigi; Pierantoni, Luca; Laudadio, Emiliano
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/308981
Citazioni:
PBEsol/HSE Functional: A promising candidate for Vanadium dioxide (B) characterization / Mohebbi, Elaheh; Pavoni, Eleonora; Mencarelli, Davide; Stipa, Pierluigi; Pierantoni, Luca; Laudadio, Emiliano. - In: RSC ADVANCES. - ISSN 2046-2069. - ELETTRONICO. - 12:48(2022), pp. 31255-31263. [10.1039/D2RA04322J]
Abstract:
A VO2(B) polymorph has been thoroughly investigated by means of density functional theory (DFT) calculations to evaluate the structure, Raman spectrum, cohesive energy, phonon band structure, an delectronic and optical properties. Among the computed Raman modes, eight of them have been assigned to t...he VO2(B) structure in full agreement with the corresponding experimental spectra. The minimized structure of the VO2(B) polymorph indicated the presence of negative frequencies in its phonon dispersion curves, confirming the dynamic instability of this material. Herein, the combination of generalized gradient approximation (GGA)/PBEsol with a hybrid HSE functional has been employed to perform ab initio calculations on VO2(B), since the conventional semi-local DFT calculations are believed to underestimate the band gap of materials. By considering the electronic structure calculations, for the first time, we found that the calibration of the PBEsol functional can efficiently model the metallic-like properties of VO2(B) with a band gap of 0.26 eV, while the corresponding electronic bandgap of VO2(B) based on the HSE functional possesses a larger band gap of 0.67 eV. The prediction of optical characteristics of VO2(B) indicated that the optical conductivity of VO2(B) lies in the infrared region of light. This work strongly suggests the combination of GGA/PBEsol with HSE hybrid functionals to carefully describe the physical properties of smart materials exploitable in electronics and optoelectronics applications. The nanostructure of VO2(B) looks promising for IR photodetectors and smart windows applications as a semiconductor material with excellent optical features. It is predicted that in the future VO2(B) will continue to expand the envelope of its capabilities because of its remarkable properties.
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Real-Time Removal of Topographic Artifacts in Scanning Microwave Microscopy
Anno: 2021
Rivista: IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
Autori/autrici: Fabi, G.; Joseph, C. H.; Pavoni, E.; Wang, X.; Hadi, R. A.; Hwang, J. C. M.; Morini, A.; Farina, M.
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/289104
Citazioni:
Real-Time Removal of Topographic Artifacts in Scanning Microwave Microscopy / Fabi, G.; Joseph, C. H.; Pavoni, E.; Wang, X.; Hadi, R. A.; Hwang, J. C. M.; Morini, A.; Farina, M.. - In: IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES. - ISSN 0018-9480. - 69:5(2021), pp. 2662-2672. [10.1109/TMTT.2021.3060756]
Abstract:
Near-field scanning microwave microscopy (SMM) employs microwave radiation to image and characterize samples down to the atomic scale, including soft biological structures or inorganic materials, such as ferroelectric films. However, SMM generally also senses sample topography; hypersensitivity to t...opography becomes problematic with additional parasitic contributions and may partially or completely mask nontopographic sample features in the data, such as contrast in electrical conductivity or permittivity. This work proposes a simple and effective procedure to remove unwanted parasitic effects from SMM images. Differently from existing procedures, the method is applicable either in postprocessing or in real time, i.e., during the scanning operation. This allows the immediate visualization of nontopographic sample features in the instrument screen. As a proof of concept, hafnium zirconium oxide (HfZrO) ferroelectric film with high surface roughness is studied; unwanted contributions were removed from SMM data, providing a clear map of the sample ferroelectric structure that was originally hidden.
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Biosensore a Transistor a Effetto di Campo (FET) per la Rilevazione di Particelle Virali
Anno: 2021
Autori/autrici: Di Marino, Daniele; D'Agostino, Mattia; Ardiccioni, Chiara; Romagnoli, Alice; D'Annessa, Ilda; Mencarelli, Davide; Pavoni, Eleonora; Crippa, Paolo; Biagetti, Giorgio; Pierantoni, Luca; Farina, Marco
Lingua: ITA
Classificazione IRIS: 6.1 Brevetto
Scheda completa IRIS: https://iris.univpm.it/handle/11566/329412
Citazioni:
Biosensore a Transistor a Effetto di Campo (FET) per la Rilevazione di Particelle Virali / Di Marino, Daniele; D'Agostino, Mattia; Ardiccioni, Chiara; Romagnoli, Alice; D'Annessa, Ilda; Mencarelli, Davide; Pavoni, Eleonora; Crippa, Paolo; Biagetti, Giorgio; Pierantoni, Luca; Farina, Marco. - ELETTRONICO. - (2021).
Abstract:
La presente invenzione riguarda un biosensore a transistor a effetto di campo (FET) ed un dispositivo che lo comprende per la rilevazione di particelle virali e/o loro frammenti. Formano oggetto dell’invenzione anche l’uso in vitro, un metodo, e un kit comprendente detto biosensore e/o disposit...ivo per la diagnosi di infezioni virali, nonché un procedimento per la preparazione di un biosensore a transistor a effetto di campo per la rilevazione di particelle virali e/o loro frammenti.
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Attoampere Nanoelectrochemistry
Anno: 2021
Rivista: SMALL
Autori/autrici: Grall, Simon; Alić, Ivan; Pavoni, Eleonora; Awadein, Mohamed; Fujii, Teruo; Müllegger, Stefan; Farina, Marco; Clément, Nicolas; Gramse, Georg
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/290736
Citazioni:
Attoampere Nanoelectrochemistry / Grall, Simon; Alić, Ivan; Pavoni, Eleonora; Awadein, Mohamed; Fujii, Teruo; Müllegger, Stefan; Farina, Marco; Clément, Nicolas; Gramse, Georg. - In: SMALL. - ISSN 1613-6810. - 17:29(2021). [10.1002/smll.202101253]
Abstract:
Electrochemical microscopy techniques have extended the understanding of surface chemistry to the micrometer and even sub-micrometer level. However, fundamental questions related to charge transport at the solidelectrolyte interface, such as catalytic reactions or operation of individual ion cha...nnels, require improved spatial resolutions down to the nanoscale. A prerequisite for single-molecule electrochemical sensitivity is the reliable detection of a few electrons per second, that is, currents in the atto-Ampere (10−18 A) range, 1000 times below today’s electrochemical microscopes. This work reports local cyclic voltammetry (CV) measurements at the solid-liquid interface on ferrocene self-assembled monolayer (SAM) with sub-atto-Ampere sensitivity and simultaneous spatial resolution < 80 nm. Such sensitivity is obtained through measurements of the charging of the local faradaic interface capacitance at GHz frequencies. Nanometer-scale details of different molecular organizations with a 19% packing density difference are resolved, with an extremely small dispersion of the molecular electrical properties. This is predicted previously based on weak electrostatic interactions between neighboring redox molecules in a SAM configuration. These results open new perspectives for nano-electrochemistry like the study of quantum mechanical resonance in complex molecules and a wide range of applications from electrochemical catalysis to biophysics.
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Quantitative Characterization of Platinum Diselenide Electrical Conductivity With an Inverted Scanning Microwave Microscope
Anno: 2021
Rivista: IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
Autori/autrici: Fabi, Gianluca; Jin, Xin; Pavoni, Eleonora; Joseph, C. H.; Donato, Andrea Di; Mencarelli, Davide; Wang, Xiaopeng; Hadi, Richard Al; Morini, Antonio; Hwang, James C. M.; Farina, Marco
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/290059
Citazioni:
Quantitative Characterization of Platinum Diselenide Electrical Conductivity With an Inverted Scanning Microwave Microscope / Fabi, Gianluca; Jin, Xin; Pavoni, Eleonora; Joseph, C. H.; Donato, Andrea Di; Mencarelli, Davide; Wang, Xiaopeng; Hadi, Richard Al; Morini, Antonio; Hwang, James C. M.; Farina, Marco. - In: IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES. - ISSN 0018-9480. - 69:7(2021), pp. 3348-3359. [10.1109/TMTT.2021.3072374]
Abstract:
Near-field scanning microwave microscopy is a technique with increasing popularity for the study of nanometer-scale electrical properties of samples. Here, we present an approach to quantify sample properties in images obtained with an inverted scanning microwave microscope (iSMM), recently introduc...ed by our group. In particular, this study reports the analysis of the local electrical conductivity of a platinum diselenide sample and proves its semimetal behavior. The approach is validated by a full-wave numerical model, reproducing the complete iSMM operation as well as all steps of the calibration algorithms. To extract local sample properties, this article provides two calibration procedures, respectively, for transmission and reflection mode measurements, based on a two-port equivalent circuit of the iSMM. This enables the high-frequency quantitative characterization of a wide variety of samples and surfaces.
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Carbazole-Terpyridine Donor-Acceptor Dyads with Rigid π-Conjugated Bridges
Anno: 2019
Rivista: CHEMPLUSCHEM
Autori/autrici: Matteucci, Elia; Baschieri, Andrea; Sambri, Letizia; Monti, Filippo; Pavoni, Eleonora; Bandini, Elisa; Armaroli, Nicola
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315651
Citazioni:
Carbazole-Terpyridine Donor-Acceptor Dyads with Rigid π-Conjugated Bridges / Matteucci, Elia; Baschieri, Andrea; Sambri, Letizia; Monti, Filippo; Pavoni, Eleonora; Bandini, Elisa; Armaroli, Nicola. - In: CHEMPLUSCHEM. - ISSN 2192-6506. - 84:9(2019), pp. 1353-1365. [10.1002/cplu.201900213]
Abstract:
A series of molecules in which 9H-carbazole (electron donor, D) and 2,2 ':6 ',2 ''-terpyridine (electron acceptor, A) are connected through rigid pi-conjugated bridges (D-pi-A systems) have been synthesized and their photophysical properties examined in detail, with the support of DFT calculations. ...The bridges are made of different sequences of ethynylene, phenylene, and anthracene groups. The synthetic strategies involve condensation of 2-acetylpyridine with the aromatic aldehyde moiety on different functionalized pi-conjugated bridges and couplings with carbazole derivatives. The system incorporating anthracene in the bridge shows the typical absorption and emission fingerprints of this polycyclic hydrocarbon. The other systems have HOMOs and LUMOs centred, respectively, over the carbazole and the bridge and exhibit solvatochromic charge-transfer (CT) luminescence with high photoluminescence yield up to 70 %, except when an ethynylene unit is directly attached to the carbazole ring, due to a trans-bent non-emissive pi-sigma* excited state.
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Nanoscale characterization of biological cells with inverted scanning microwave microscopy
Anno: 2019
Autori/autrici: Fabi, Gianluca; James, Hwang; Christopher, Joseph; Pavoni, Eleonora; Xin, Jin; Xiaopeng, Wang; Mencarelli, Davide; Andera di Donato, ; Morini, Antonio; Yan, Zhao; Richard Al Hadi, ; Farina, Marco
Lingua: ENG
Classificazione IRIS: 4.3 Poster
Scheda completa IRIS: https://iris.univpm.it/handle/11566/270427
Citazioni:
Nanoscale characterization of biological cells with inverted scanning microwave microscopy / Fabi, Gianluca; James, Hwang; Christopher, Joseph; Pavoni, Eleonora; Xin, Jin; Xiaopeng, Wang; Mencarelli, Davide; Andera di Donato, ; Morini, Antonio; Yan, Zhao; Richard Al Hadi, ; Farina, Marco. - (2019). (Intervento presentato al convegno Nanoinnovation 2019 tenutosi a Roma nel 11-14 Giugno).
Abstract:
Near-field scanning microwave microscopy (SMM) is a technique allowing the study of the electrical properties of matter on the nanometer scale. SMM is proven to be capable of non-invasive, label-free characterization of biological cells. Recently, a new technique called inverted-SMM (iSMM) has been ...introduced by us and is different from previously developed SMM techniques. iSMM allows two-port measurements where both reflection and transmission scattering parameters can be recorded. Several advantages are achieved with this configuration, including broader bandwidth and improved dynamic range. In this work, the high frequency characterization of dried L6 rat myocyte cells using iSMM is presented. In particular, imaging capabilities of the technique are proved showing remarkable quality and sensitivity.
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Inverted scanning microwave microscope for in vitro imaging and characterization of biological cells
Anno: 2019
Rivista: APPLIED PHYSICS LETTERS
Autori/autrici: Farina, Marco; Jin, Xin; Fabi, Gianluca; Pavoni, Eleonora; di Donato, Andrea; Mencarelli, Davide; Morini, Antonio; Piacenza, Francesco; Al Hadi, Richard; Zhao, Yan; Ning, Yaqing; Pietrangelo, Tiziana; Cheng, Xuanhong; Hwang, James C. M.
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/264224
Citazioni:
Inverted scanning microwave microscope for in vitro imaging and characterization of biological cells / Farina, Marco; Jin, Xin; Fabi, Gianluca; Pavoni, Eleonora; di Donato, Andrea; Mencarelli, Davide; Morini, Antonio; Piacenza, Francesco; Al Hadi, Richard; Zhao, Yan; Ning, Yaqing; Pietrangelo, Tiziana; Cheng, Xuanhong; Hwang, James C. M.. - In: APPLIED PHYSICS LETTERS. - ISSN 0003-6951. - 114:9(2019), p. 093703. [10.1063/1.5086259]
Abstract:
This paper presents an instrument called an inverted scanning microwave microscope (iSMM), which is capable of performing noninvasive and label-free imaging and characterization of intracellular structures of a live cell on the nanometer scale. In particular, the iSMM is sensitive to not only surf...ace structures but also electromagnetic properties up to one micrometer below the surface. Conveniently, the iSMM can be constructed through straightforward conversion of any scanning probe microscope, such as an atomic force microscope and a scanning tunneling microscope, with a simple metal probe to outperform a traditional SMM in terms of ruggedness, bandwidth, sensitivity, and dynamic range. By contrast, the application of the traditional SMM to date has been limited to mainly surface physics and semiconductor technology because the traditional SMM requires a fragile and expensive probe and is incompatible with saline solution or live cells.
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Blisters on graphite surface: a scanning microwave microscopy investigation
Anno: 2019
Rivista: RSC ADVANCES
Autori/autrici: Pavoni, Eleonora; Yivlialin, Rossella; Christopher, Hardly Joseph; Fabi, Gianluca; Mencarelli, Davide; Pierantoni, Luca; Bussetti, Gianlorenzo; Farina, Marco
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/269083
Citazioni:
Blisters on graphite surface: a scanning microwave microscopy investigation / Pavoni, Eleonora; Yivlialin, Rossella; Christopher, Hardly Joseph; Fabi, Gianluca; Mencarelli, Davide; Pierantoni, Luca; Bussetti, Gianlorenzo; Farina, Marco. - In: RSC ADVANCES. - ISSN 2046-2069. - 9:40(2019), pp. 23156-23160. [10.1039/C9RA04667D]
Abstract:
Scanning microwave microscopy (SMM) is based on the interaction between a sample and an electromagnetic evanescent field, in the microwave frequency range. SMM is usually coupled with a scanning probe microscopy (SPM) technique such as in our case, a scanning tunneling microscope (STM). In this way,... the STM tip is used to control the distance between the probe and the sample while acting as an antenna for the microwave field. Thanks to the peculiarity of our home-made setup, the SMM is a suitable method to study blisters formed on HOPG surface as consequence of an electrochemical treatment. Our system has a “broad-band” approach that opens the way to perform local microwave spectroscopy over a broad frequency range. Moreover, microwaves have the ability to penetrate into the sample allowing the sub-surface characterization of materials. The application of the SMM to characterize blisters formed on the HOPG surface provides information on the sub-layer structures.
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Inverted Scanning Microwave Microscopy for Nanometer-scale Imaging and Characterization of Platinum Diselenide
Anno: 2019
Autori/autrici: Fabi, Gianluca; Jin, Xin; Hwang, James C. M.; Joseph, C. H.; Pavoni, Eleonora; Li, Lei; Xiong, Kuanchen; Ning, Yaqing; Mencarelli, Davide; di Donato, Andrea; Morini, Antonio; Zhao, Yan; Al Hadi, Richard; Farina, Marco
Lingua: ENG
Classificazione IRIS: 4.1 Contributo in Atti di convegno
Scheda completa IRIS: https://iris.univpm.it/handle/11566/270170
Citazioni:
Inverted Scanning Microwave Microscopy for Nanometer-scale Imaging and Characterization of Platinum Diselenide / Fabi, Gianluca; Jin, Xin; Hwang, James C. M.; Joseph, C. H.; Pavoni, Eleonora; Li, Lei; Xiong, Kuanchen; Ning, Yaqing; Mencarelli, Davide; di Donato, Andrea; Morini, Antonio; Zhao, Yan; Al Hadi, Richard; Farina, Marco. - (2019), pp. 1115-1117. (Intervento presentato al convegno IEEE International Microwave Symposium tenutosi a Boston (USA) nel 2-7 Giugno 2019) [10.1109/MWSYM.2019.8701124].
Abstract:
Near-field scanning microwave microscopy (SMM) is a technique gaining popularity for the study of the electrical properties of both soft and hard matter on the nanometer scale. Despite the current focus on semiconductors, the applications of SMM on new two-dimensional materials such as platinum dise...lenide (PtSe 2 ) are still in an initial stage. In this work, the imaging capabilities of an innovative SMM and the analysis of the electrical properties of PtSe 2 are demonstrated.
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Measuring zinc in biological nanovesicles by multiple analytical approaches
Anno: 2018
Rivista: JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY
Autori/autrici: Piacenza, Francesco; Biesemeier, Antje; Farina, Marco; Piva, Francesco; Jin, Xin; Pavoni, Eleonora; Nisi, Lorenzo; Cardelli, Maurizio; Costarelli, Laura; Giacconi, Robertina; Basso, Andrea; Pierpaoli, Elisa; Provinciali, Mauro; Hwang, James C. M.; Morini, Antonio; di Donato, Andrea; Malavolta, Marco
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/256174
Citazioni:
Measuring zinc in biological nanovesicles by multiple analytical approaches / Piacenza, Francesco; Biesemeier, Antje; Farina, Marco; Piva, Francesco; Jin, Xin; Pavoni, Eleonora; Nisi, Lorenzo; Cardelli, Maurizio; Costarelli, Laura; Giacconi, Robertina; Basso, Andrea; Pierpaoli, Elisa; Provinciali, Mauro; Hwang, James C. M.; Morini, Antonio; di Donato, Andrea; Malavolta, Marco. - In: JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY. - ISSN 0946-672X. - STAMPA. - 48:(2018), pp. 58-66. [10.1016/j.jtemb.2018.03.010]
Abstract:
Exosomes are nanovesicles known to mediate intercellular communication. Although it is established that zinc ions can act as intracellular signaling factors, the measurement of zinc in circulating nanovesicles has not yet been attempted. Providing evidence of the existence of this zinc fraction and ...methods for its measurement might be important to advance our knowledge of zinc status and its relevance in diseases. Exosomes from 0.5 ml of either fresh or frozen human plasma were isolated by differential centrifugation. A morphological and dimensional evaluation at the nanoscale level was performed by atomic force microscopy (AFM) and Transmission Electron Microscopy (TEM). Energy Dispersive X-Ray Microanalysis (EDX) revealed the elemental composition of exosomes and their respective total Zinc content on a quantitative basis. The zinc mole fraction (in at%) was correlated to the phosphorous mole fraction, which is indicative for exosomal membrane material. Both fresh (Zn/P 0.09 ± 0.01) and frozen exosomes (Zn/P 0.08 ± 0.02) had a significant zinc content, which increased up to 1.09 ± 0.12 for frozen exosomes when treated with increasing amounts of zinc (100–500 μM; each p < 0.05). Interestingly, after zinc addition, the Calcium mole fractions decreased accordingly suggesting a possible exchange by zinc. In order to estimate the intra-exosomal labile zinc content, an Imaging Flow Cytometry approach was developed by using the specific membrane permeable zinc-probe Fluozin-3AM. A labile zinc content of 0.59 ± 0.27 nM was calculated but it is likely that the measurement may be affected by purification and isolation conditions. This study suggests that circulating nano-vesicular-zinc can represent a newly discovered zinc fraction in the blood plasma whose functional and biological properties will have to be further investigated in future studies.
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Extracellular guanosine 5’-triphosphate induces human muscle satellite cells to release exosomes stuffed with guanosine
Anno: 2018
Rivista: FRONTIERS IN PHARMACOLOGY
Autori/autrici: Pietrangelo, Tiziana; Sara Di Filippo, Ester; Locatelli, Marcello; Piacenza, Francesco; Farina, Marco; Pavoni, Eleonora; DI DONATO, Andrea; Innosa, Denise; Provinciali, Mauro; Fulle, Stefania
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/255326
Citazioni:
Extracellular guanosine 5’-triphosphate induces human muscle satellite cells to release exosomes stuffed with guanosine / Pietrangelo, Tiziana; Sara Di Filippo, Ester; Locatelli, Marcello; Piacenza, Francesco; Farina, Marco; Pavoni, Eleonora; DI DONATO, Andrea; Innosa, Denise; Provinciali, Mauro; Fulle, Stefania. - In: FRONTIERS IN PHARMACOLOGY. - ISSN 1663-9812. - (2018). [10.3389/fphar.2018.00152]
Abstract:
The extracellular guanosine 5’-triphosphate, GTP, has been demonstrated to be an enhancer of myogenic cell differentiation in a murine cell line, not yet in human muscle cells. Our hypothesis was that GTP could influence also human skeletal muscle regeneration, specifically in the first phases. We... tested GTP stimulus on human muscle precursor cells established in culture by human satellite cells derived from Vastus Laterlais of three young male. Our data show that extracellular GTP a) up-regulated miRNA (specifically miR133a and miR133b) and myogenic regulator factor and b) induces human myogenic precursor cells to release exosomes stuffed with guanosine based molecules (mainly guanosine) in the extracellular milieu. We think that probably these exosomes could be addressed to influence by means of their content (mainly guanosine) in paracrine or autocrine manner the surrounding cells and/or at distance other muscles or tissues.
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Imaging of sub-cellular structures and organelles by an STM-assisted Scanning Microwave Microscope at mm-Waves
Anno: 2018
Rivista: IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST
Autori/autrici: Farina, Marco; Hwang, James C. M.; Di Donato, Andrea; Pavoni, Eleonora; Fabi, Gianluca; Morini, Antonio; Piacenza, Francesco; Di Filippo, Ester; Pietrangelo, Tiziana
Lingua: ENG
Classificazione IRIS: 4.1 Contributo in Atti di convegno
Scheda completa IRIS: https://iris.univpm.it/handle/11566/260187
Citazioni:
Imaging of sub-cellular structures and organelles by an STM-assisted Scanning Microwave Microscope at mm-Waves / Farina, Marco; Hwang, James C. M.; Di Donato, Andrea; Pavoni, Eleonora; Fabi, Gianluca; Morini, Antonio; Piacenza, Francesco; Di Filippo, Ester; Pietrangelo, Tiziana. - 2018-:(2018), pp. 111-114. (Intervento presentato al convegno 2018 IEEE/MTT-S International Microwave Symposium, IMS 2018 tenutosi a usa nel 2018) [10.1109/MWSYM.2018.8439165].
Abstract:
Recently, near-field scanning microwave microscope has become popular in the characterization of materials, in particular, semiconductors on the nanometer scale. However, its application to biological structures is still at the embryo stage due to challenges in probing wet and soft samples with litt...le dielectric contrast. In this work, we used our homemade scanning microwave microscope to overcome some of the challenges to demonstrate the imaging and characterization of isolated mitochondria in the frequency range 28–33 GHz.
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Wafer-scale very large memory windows in graphene monolayer/HfZrO ferroelectric capacitors
Anno: 2018
Rivista: NANOTECHNOLOGY
Autori/autrici: Dragoman, Mircea; Modreanu, Mircea; Povey, Ian M; Dinescu, Adrian; Dragoman, Daniela; Di Donato, Andrea; Pavoni, Eleonora; Farina, Marco
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/259450
Citazioni:
Wafer-scale very large memory windows in graphene monolayer/HfZrO ferroelectric capacitors / Dragoman, Mircea; Modreanu, Mircea; Povey, Ian M; Dinescu, Adrian; Dragoman, Daniela; Di Donato, Andrea; Pavoni, Eleonora; Farina, Marco. - In: NANOTECHNOLOGY. - ISSN 0957-4484. - 29:42(2018), p. 425204. [10.1088/1361-6528/aad75e]
Abstract:
We have fabricated and electrically characterized at the wafer scale tens of metal-ferroelectric (HfZrO)-semiconductor capacitors and metal-graphene monolayer-ferroelectric (HfZrO)-semiconductor capacitors with the same top electrode dimensions. We have found that the memory windows of the capacitor...s containing graphene are 3-4 times larger than the ferroelectric capacitors without graphene, and increase even more after annealing. This physical effect can be attributed to the additional electric field exerted by the graphene monolayer on the HfZrO ferroelectric semiconductor capacitor, and to the negative thermal extension coefficient of graphene, respectively.
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Comparative micro-Raman study on standard, cross-linked and vitamin E-blended polyethylene acetabular cups after long-term in vitro testing and ageing
Anno: 2017
Rivista: JOURNAL OF RAMAN SPECTROSCOPY
Autori/autrici: Taddei, P; Pavoni, E; Affatato, S
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315288
Citazioni:
Comparative micro-Raman study on standard, cross-linked and vitamin E-blended polyethylene acetabular cups after long-term in vitro testing and ageing / Taddei, P; Pavoni, E; Affatato, S. - In: JOURNAL OF RAMAN SPECTROSCOPY. - ISSN 0377-0486. - 48:8(2017), pp. 1065-1074. [10.1002/jrs.5172]
Abstract:
Ultra-highmolecular-weight polyethylene has been used in total joint replacement for the last three decades. Many attempts have been made to improve the wear behaviour of this material. Highly cross-linked polyethylene (XLPE) has been developed to decrease the wear rate, while the addition of stabil...izers such as vitamin E has been proposed to slow the oxidation processes.In this study, we compared the wear behaviour of conventional ultra-high molecular-weight polyethylene, XLPE and vitamin E-added XLPE acetabular cups for total hip arthroplasty. The samples were run for five million cycles on a hip joint simulator (first test), then underwent an accelerated ageing treatment, were tested again for two million cycles (second test) and finally were run for another two million cycles in presence of third-body particles (third test). Our study showed that vitamin E-added XLPE cups had a better wear behaviour only in the long-term and more severe testing conditions: in the third test, they underwent the lowest increase in wear rate. Micro-Raman spectroscopy allowed us to analyse the wear degradation of the cups on a molecular scale, and differences in the wear mechanisms were revealed. The presence of vitamin E did not prevent structural changes upon the first test, while it did in ageing and in the second test. In the third test, more significant structural changes were observed; the XLPE cups, which lost the lowest mass, had the most modified articular surface. These morphological aspects should be taken into account, together with gravimetric wear rates, in the characterization of wear degradation. Copyright (C) 2017 John Wiley & Sons, Ltd.
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Transfer of metallic debris after in vitro ceramic-on-metal simulation: Wear and degradation in Biolox Delta composite femoral heads
Anno: 2017
Rivista: COMPOSITES. PART B, ENGINEERING
Autori/autrici: Taddei, Paola; Ruggiero, Alessandro; Pavoni, Eleonora; Affatato, Saverio
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315648
Citazioni:
Transfer of metallic debris after in vitro ceramic-on-metal simulation: Wear and degradation in Biolox Delta composite femoral heads / Taddei, Paola; Ruggiero, Alessandro; Pavoni, Eleonora; Affatato, Saverio. - In: COMPOSITES. PART B, ENGINEERING. - ISSN 1359-8368. - 115:(2017), pp. 477-487. [10.1016/j.compositesb.2016.07.008]
Abstract:
This study was aimed at investigating the effects of the transfer of metallic debris during an in vitro wear test on ceramic femoral heads articulating against metallic acetabular cups. In particular, Biolox (R) Delta ceramic femoral heads of two different diameters (32 and 36 mm, three samples of e...ach set) were run for five million cycles onto a hip wear simulator using bovine calf serum as lubricant. Wear and degradation of Biolox (R) Delta Composite femoral heads were evaluated by a gravimetric method and by micro-Raman spectroscopy, which was used to investigate possible phase changes upon the particles deposit, by assessing the monoclinic zirconia content and quantifying the tetragonal -> monoclinic zirconia transformation. Our results showed that after five million cycles, the 32 mm-acetabular cups lost a mass higher than the 36 mm-ones. Metal transfer was observed on all the Biolox (R) Delta ceramic femoral heads and determined a worsening of all roughness parameters. The micro-Raman analyses of the in vitro tested femoral heads confirmed the results previously obtained on retrievals, i.e. the stress related to metal transfer appeared to be a particularly severe condition able to induce the tetragonal -> monoclinic zirconia phase transformation. The extent of the transformation appeared higher than that observed in vivo for Biolox (R) Delta-on-Biolox (R) Delta couplings. On average, the 36 mm-femoral heads seemed more detrimentally affected by metal transfer than the 32 mm-ones; one femoral head belonging to the first set of samples underwent the highest extent of phase transformation and the highest depth involved, which in the worn centre area appeared on average higher for the 36 mm-components than for the 32 mm-ones. (C) 2016 Elsevier Ltd. All rights reserved.
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Raman and Photoemission Spectroscopic Analyses of Explanted Biolox® Delta Femoral Heads Showing Metal Transfer
Anno: 2017
Rivista: MATERIALS
Autori/autrici: Taddei, Paola; Pavoni, Eleonora; Affatato, Saverio
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315649
Citazioni:
Raman and Photoemission Spectroscopic Analyses of Explanted Biolox® Delta Femoral Heads Showing Metal Transfer / Taddei, Paola; Pavoni, Eleonora; Affatato, Saverio. - In: MATERIALS. - ISSN 1996-1944. - 10:7(2017), p. 744. [10.3390/ma10070744]
Abstract:
Biolox (R) delta has been widely used in joint replacements thanks to its high strength and wear resistance. In this study, eleven Biolox (R) delta femoral head retrievals affected by metal transfer (MT) were analysed by Raman spectroscopy to estimate the tetragonal to monoclinic zirconia phase tran...sformation, whose occurrence may compromise ceramic chemical stability and mechanical strength. The residual stress state was evaluated by both Raman and photoemission spectroscopy. Vm monoclinic zirconia contents were higher near the centre of the articulating surface and in the MT area than in the border control area of the retrievals. In only one retrieval, stress related to MT appeared a more severe condition, able to induce zirconia phase transformation; for all the others, stresses related to loading in the central region and related to MT, were conducive to a zirconia phase transformation of nearly the same extent. V-m depth profiling analyses showed that the transformation involved different thicknesses in different samples. Raman data allowed for the investigation of the mechanism of zirconia phase transformation and confirmed that the growth stage was absent and the nucleation stage was not occurring as freely as it would in unconstrained zirconia.
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Does cyclic stress and accelerated ageing influence the wear behavior of highly crosslinked polyethylene?
Anno: 2016
Rivista: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
Autori/autrici: Affatato, Saverio; De Mattia, Jonathan Salvatore; Bracco, Pierangiola; Pavoni, Eleonora; Taddei, Paola
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315637
Citazioni:
Does cyclic stress and accelerated ageing influence the wear behavior of highly crosslinked polyethylene? / Affatato, Saverio; De Mattia, Jonathan Salvatore; Bracco, Pierangiola; Pavoni, Eleonora; Taddei, Paola. - In: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS. - ISSN 1751-6161. - 59:(2016), pp. 418-429. [10.1016/j.jmbbm.2016.02.029]
Abstract:
First-generation (irradiated and remelted or annealed) and second-generation (irradiated and vitamin E blended or doped) highly crosslinked polyethylenes were introduced in the last decade to solve the problems of wear and osteolysis.In this study, the influence of the Vitamin-E addition on crosslin...ked polyethylene (XLPE_VE) was evaluated by comparing the in vitro wear behavior of crosslinked polyethylene (XLPE) versus Vitamin-E blended polyethylene XLPE and conventional ultra-high molecular weight polyethylene (STD_PE) acetabular cups, after accelerated ageing according to ASTM F2003-02 (70.0 +/- 0.1 degrees C, pure oxygen at 5 bar for 14 days). The test was performed using a hip joint simulator run for two millions cycles, under bovine calf serum as lubricant.Mass loss was found to decrease along the series XLPE_VE>STD_PE>XLPE, although no statistically significant differences were found between the mass losses of the three sets of cups. Micro-Raman spectroscopy was used to investigate at a molecular level the morphology changes induced by wear. The spectroscopic analyses showed that the accelerated ageing determined different wear mechanisms and molecular rearrangements during testing with regards to the changes in both the chain orientation and the distribution of the all-trans sequences within the orthorhombic, amorphous and third phases. The results of the present study showed that the addition of vitamin E was not effective to improve the gravimetric wear of PE after accelerated ageing. However, from a molecular point of view, the XLPE_VE acetabular cups tested after accelerated ageing appeared definitely less damaged than the STD_PE ones and comparable to XLPE samples. (C) 2016 Elsevier Ltd. All rights reserved.
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Wear performance of neat and vitamin E blended highly cross-linked PE under severe conditions: The combined effect of accelerated ageing and third body particles during wear test
Anno: 2016
Rivista: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
Autori/autrici: Affatato, Saverio; De Mattia, Jonathan Salvatore; Bracco, Pierangiola; Pavoni, Eleonora; Taddei, Paola
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315647
Citazioni:
Wear performance of neat and vitamin E blended highly cross-linked PE under severe conditions: The combined effect of accelerated ageing and third body particles during wear test / Affatato, Saverio; De Mattia, Jonathan Salvatore; Bracco, Pierangiola; Pavoni, Eleonora; Taddei, Paola. - In: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS. - ISSN 1751-6161. - 64:(2016), pp. 240-252. [10.1016/j.jmbbm.2016.08.003]
Abstract:
The objective of this study is to evaluate the effects of third-body particles on the in vitro wear behaviour of three different sets of polyethylene acetabular cups after prolonged testing in a hip simulator and accelerated ageing. Vitamin E-blended, cross-linked polyethylene (XLPE_VE), cross-linke...d polyethylene (XLPE) and conventional polyethylene (STD_PE) acetabular cups were simulator tested for two million cycles under severe conditions (i.e. by adding third-body particles to the bovine calf serum lubricant). Micro-Fourier Transform Infrared and micro Raman spectroscopic analyses, differential scanning calorimetry, and crosslink density measurements were used to characterize the samples at a molecular level.The STD_PE cups had twice mass loss than the XLPE_VE components and four times than the XLPE samples; statistically significant differences were found between the mass losses of the three sets of cups. The observed wear trend was justified on the basis of the differences in cross-link density among the samples (XLPE>XLPE_VE>STD_PE).FTIR crystallinity profiles, bulk DSC crystallinity and surface micro-Raman crystallinity seemed to have a similar behaviour upon testing: all of them (as well as the all-trans and orthotrans contents) revealed the most significant changes in XLPE and XLPE_VE samples. The more severe third-body wear testing conditions determined more noticeable changes in all spectroscopic markers with respect to previous tests. Unexpectedly, traces of bulk oxidation were found in both STD_PE (unirradiated) and XLPE (remelting-stabilized), which were expected to be stable to oxidation; on the contrary, XLPE_VE demonstrated a high oxidative stability in the present, highly demanding conditions. (C) 2016 Elsevier Ltd. All rights reserved.
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Influence of grafting with acrylate compounds on the conformational rearrangements of silk fibroin upon electrospinning and treatment with aqueous methanol
Anno: 2016
Rivista: JOURNAL OF RAMAN SPECTROSCOPY
Autori/autrici: Pavoni, E; Tsukada, M; Taddei, P
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315645
Citazioni:
Influence of grafting with acrylate compounds on the conformational rearrangements of silk fibroin upon electrospinning and treatment with aqueous methanol / Pavoni, E; Tsukada, M; Taddei, P. - In: JOURNAL OF RAMAN SPECTROSCOPY. - ISSN 0377-0486. - 47:11(2016), pp. 1367-1374. [10.1002/jrs.4974]
Abstract:
Silk fabrics from Bombyx mori silkworm were grafted with 2-hydroxyethyl methacrylate (HEMA) as well as a binary system of HEMA and 4-hydroxybutyl acrylate (HBA) and then analysed by Raman and infrared (IR) spectroscopy to elucidate the interactions between the components and their possible conformat...ional changes. The samples were then dissolved in trifluoroacetic acid and electrospun; the influence of the grafted polymers on the silk fibroin rearrangements upon these treatments was investigated by vibrational spectroscopy. Upon grafting, the fabrics underwent conformational rearrangements towards a more unordered state, although they kept their prevailing beta-sheet conformation; also the polymeric component underwent hydrogen bonding and backbone rearrangements upon interaction with silk fibroin and the occurrence of strong covalent bonds cannot be excluded. By immersing the as-electrospun grafted and pure fibroin nanofibres (prevalently unordered) in aqueous methanol, they partially recovered the beta-sheet content observed in the corresponding starting fabrics; the percentage of recovery decreased along the series: pure silk > HEMA-grafted silk > HEMA and HBA-grafted silk. This trend suggests that the presence of the polyHEMA grafted component hinders the silk fibroin recrystallization into beta-sheet upon aqueous methanol treatment; moreover, the addition of the more sterically hindered HBA monomer in the grafting system further prevented this process. Copyright (C) 2016 John Wiley & Sons, Ltd.
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[60]Fullerene-porphyrin [n]pseudorotaxanes: self-assembly, photophysics and third-order NLO response
Anno: 2016
Rivista: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autori/autrici: Đorđević, L; Marangoni, T; De Leo, F; Papagiannouli, I; Aloukos, P; Couris, S; Pavoni, E; Monti, F; Armaroli, N; Prato, M; Bonifazi, D
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315635
Citazioni:
[60]Fullerene-porphyrin [n]pseudorotaxanes: self-assembly, photophysics and third-order NLO response / Đorđević, L; Marangoni, T; De Leo, F; Papagiannouli, I; Aloukos, P; Couris, S; Pavoni, E; Monti, F; Armaroli, N; Prato, M; Bonifazi, D. - In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS. - ISSN 1463-9076. - 18:17(2016), pp. 11858-11868. [10.1039/c5cp06055a]
Abstract:
By means of different spectroscopic techniques, we investigate a novel series of porphyrin derivatives (H2TPP), connected to dibenzo-24-crown-8 (DB24C8) moieties, which undergo self-assembly with different methano[60] fullerene units bearing dibenzylammonium (DBA) cations. The formation of both [2] ...and [3]pseudorotaxanes was proved by means of NMR, UV-Vis-NIR absorption and emission spectroscopies. With the support of molecular modelling studies, spectroscopic investigations showed the presence of a secondary interaction between the porphyrin and the C-60 chromophores leading to the formation of different types of "face-to-face'' assemblies. Remarkably, investigations of the non-linear optical response of these supramolecular systems showed that individual porphyrin and fullerene derivatives exhibit significantly lower second hyperpolarizability values when compared to their pseudorotaxanes functionalised counterparts. This proves that this class of supramolecular materials possesses relevant NLO response, which strongly depends on the structural arrangement of the chromophores in solution.
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Structural study on methacrylamide-grafted Tussah silk fibroin fibres
Anno: 2016
Rivista: INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
Autori/autrici: Pavoni, Eleonora; Tozzi, Silvia; Tsukada, Masuhiro; Taddei, Paola
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315639
Citazioni:
Structural study on methacrylamide-grafted Tussah silk fibroin fibres / Pavoni, Eleonora; Tozzi, Silvia; Tsukada, Masuhiro; Taddei, Paola. - In: INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. - ISSN 0141-8130. - 88:(2016), pp. 196-205. [10.1016/j.ijbiomac.2016.03.057]
Abstract:
Tussah silk fibroin fibres were modified by grafting with methacrylamide (MAA), with weight gains ranging between 2.6% and 71.4%. Raman and IR spectroscopic analyses showed that upon grafting the fibres underwent slight conformational changes towards a more unordered state, due to the covalent and h...ydrogen bonds interactions occurring between the polymer (polyMAA) and the amorphous domains of silk fibres.To test the stability towards alkaline hydrolysis, the untreated and MAA-grafted silk fibres (weight gain of 71.4%) were immersed in NaOH 5% at 50 degrees C for different times; the IR and Raman spectroscopic techniques were utilized to elucidate the degradation mechanism as well as the rearrangements of the fibres induced by the treatment.Upon hydrolysis, both the untreated and grafted fibres underwent an enrichment in beta-sheet conformation, due to the preferential removal of the unordered domains. As a result of the covalent interactions with silk fibroin, the polymer increased its stability towards alkaline hydrolysis, since its complete solubilization was avoided and the transformation of its CONH2 groups into COO- and COOH was delayed. Vibrational spectroscopy proved to be a valid technique to investigate the mechanism and the effects of the hydrolytic attack, which are both fundamental to design new-generation silk-based materials. (C) 2016 Elsevier B.V. All rights reserved.
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Covalently Functionalized SWCNTs as Tailored p-Type Dopants for Perovskite Solar Cells
Anno: 2016
Rivista: ACS APPLIED MATERIALS & INTERFACES
Autori/autrici: Miletić, Tanja; Pavoni, Eleonora; Trifiletti, Vanira; Rizzo, Aurora; Listorti, Andrea; Colella, Silvia; Armaroli, Nicola; Bonifazi, Davide
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315640
Citazioni:
Covalently Functionalized SWCNTs as Tailored p-Type Dopants for Perovskite Solar Cells / Miletić, Tanja; Pavoni, Eleonora; Trifiletti, Vanira; Rizzo, Aurora; Listorti, Andrea; Colella, Silvia; Armaroli, Nicola; Bonifazi, Davide. - In: ACS APPLIED MATERIALS & INTERFACES. - ISSN 1944-8244. - 8:41(2016), pp. 27966-27973. [10.1021/acsami.6b08398]
Abstract:
The covalent functionalization of (7,6)-enriched single walled carbon nanotubes (SWCNTs) with oligophenylenevinylene (OPV) moieties terminating with a dimethylamino group is proposed as an efficient way to enhance the affinity of CNTs with spiro-MeOTAD in perovskite-based solar cells. The evidence o...f SWCNTs functionalization and the degree of OPV substitution on SWCNTs are established from TGA, XPS, TEM, and Raman techniques. Our tailored doping materials afford photovoltaic performances in line with conventional Li doped spiro-MeOTAD, showing at the same time a significantly improved chemical stability of the perovskite component over time. Furthermore, the comparison of the photovoltaic performances with those obtained with nonfunctionalized SWCNTs suggest that the presence of the organic appends ensures highly reproducible PV performances. These results demonstrate the suitability of this functionalized SWCNT material as a valid doping agent for spiro-MeOTAD, representing a viable alternative to the conventional Li salt.
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Stability toward alkaline hydrolysis of B. mori silk fibroin grafted with methacrylamide
Anno: 2016
Rivista: JOURNAL OF RAMAN SPECTROSCOPY
Autori/autrici: Taddei, P; Pavoni, E; Tsukada, M
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315638
Citazioni:
Stability toward alkaline hydrolysis of B. mori silk fibroin grafted with methacrylamide / Taddei, P; Pavoni, E; Tsukada, M. - In: JOURNAL OF RAMAN SPECTROSCOPY. - ISSN 0377-0486. - 47:6(2016), pp. 731-739. [10.1002/jrs.4892]
Abstract:
Bombyx mori silk fibroin fibers were grafted with methacrylamide (MAA) and characterized by Raman and infrared (IR) vibrational spectroscopy before and after hydrolysis in NaOH 5% to elucidate the possible interactions between the two components and the stability of the fibers toward alkaline hydrol...ysis.Upon grafting, the fibers underwent conformational rearrangements toward a more unordered state and lost orientation at weight gains higher than 60%. Vibrational spectroscopy disclosed the occurrence of intermolecular interactions (mainly hydrogen bonds) between B. mori silk fibroin and polyMAA in the grafted fibers, and the formation of covalent bonds has been explored.These strong interactions made the grafted fibers as a whole more stable toward alkaline hydrolysis because they prevented the solubilization of the polymer upon hydrolysis and made slower the transformation of its CONH2 groups into COOH and COO- groups.Upon hydrolysis, silk fibroin underwent an enrichment in the beta-sheet crystalline domains, because of the preferential removal of the unordered domains, which were more prone to the OH- attack. IR and Raman spectroscopy proved valid techniques to investigate the degradation mechanism and kinetics of grafted silk fibroin fibers and so for designing high-performing silk-based materials. The A(731)/A(1004) Raman intensity ratio was proposed to spectroscopically evaluate the composition of the grafted samples; its value was found to linearly increase with weight gain (R-2 = 0.998), envisaging the possibility of using Raman spectroscopy as a routine analytical technique for qualitative and quantitative characterization of grafted industrial samples. Copyright (C) 2016 John Wiley & Sons, Ltd.
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Nanomaterials for lighting and solar energy conversion
Anno: 2015
Autori/autrici: Monti, F.; Pavoni, E.; Armaroli, N.
Classificazione IRIS: 2.1 Contributo in volume (Capitolo o Saggio)
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315634
Citazioni:
Nanomaterials for lighting and solar energy conversion / Monti, F.; Pavoni, E.; Armaroli, N.. - (2015), pp. 373-414. [10.1007/978-94-017-9133-5_18]

A tailored RAFT copolymer for the dispersion of single walled carbon nanotubes in aqueous media
Anno: 2014
Rivista: POLYMER CHEMISTRY
Autori/autrici: Pavoni, E; Bandini, E; Benaglia, M; Molloy, Jk; Bergamini, G; Ceroni, P; Armaroli, N
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315631
Citazioni:
A tailored RAFT copolymer for the dispersion of single walled carbon nanotubes in aqueous media / Pavoni, E; Bandini, E; Benaglia, M; Molloy, Jk; Bergamini, G; Ceroni, P; Armaroli, N. - In: POLYMER CHEMISTRY. - ISSN 1759-9954. - ELETTRONICO. - 5:21(2014), pp. 6148-6150. [10.1039/c4py00893f]
Abstract:
The Reversible Addition-Fragmentation chain-Transfer (RAFT) synthesis of poly(glycidyl methacrylate) (PGMA) copolymers followed by the post-polymerisation treatment with morpholine allows the rational design of amphiphilic block copolymers that are capable of efficiently dispersing single walled car...bon nanotubes (SWCNTs) in aqueous media, as shown by comparative photophysical characterisation and AFM analysis.
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Homoleptic and heteroleptic Ru-II complexes with extended phenanthroline-based ligands
Anno: 2014
Rivista: POLYHEDRON
Autori/autrici: Monti, F; Hahn, U; Pavoni, E; Delavaux-Nicot, B; Nierengarten, Jf; Armaroli, N
Lingua: ENG
Classificazione IRIS: 1.1 Articolo in rivista
Scheda completa IRIS: https://iris.univpm.it/handle/11566/315629
Citazioni:
Homoleptic and heteroleptic Ru-II complexes with extended phenanthroline-based ligands / Monti, F; Hahn, U; Pavoni, E; Delavaux-Nicot, B; Nierengarten, Jf; Armaroli, N. - In: POLYHEDRON. - ISSN 0277-5387. - 82:(2014), pp. 122-131. [10.1016/j.poly.2014.05.030]
Abstract:
Four Ru-II complexes of general formula [Ru(PT)(3)](2+), [Ru(NT)(3)](2+), [Ru(PT)(bpy)(2)](2+), and [Ru(NT)(bpy)(2)](2+), where PT = 10,13-bis((triisopropylsilyl)ethynyl)dipyrido[3,2-a:2',3'-c]phenazine, NT = 10,15-bis((triisopropylsilyl)ethynyl)benzo[i]dipyrido[3,2-a:2',3'-c]phenazine and bpy = 2,2...'-bipyridine have been synthesized. Their electrochemical and photophysical properties have been studied, with the aid of DFF and TD-DFT theoretical methods. The extended phenanthroline ligand PT exhibits two reduction processes at -0.98 and -1.55 (versus SCE) and no clearly detectable oxidation processes; the more extended analogue NT is substantially easier to reduce by about 300 mV. In the four complexes, the two first reduction processes are centered on the extended phenanthroline ligands, and, according to DFT calculations, also oxidations are likely to be located on such moieties. PT and NT exhibit green-yellow fluorescence at 298 and 77K with photoluminescence quantum yields of 3.4% and 62.1%, respectively, at room temperature. At 77 K, a strong and long-lived phosphorescence is detected only for PT (lambda(max) = 658 nm, tau = 29 ms). In oxygen-free solution at 298 K [Ru(PT)(3)](2+) and [Ru(PT)(bpy)(2)](2+) exhibit a very weak emission band with lambda(max) about 700 nm, which extends towards the near infrared region and is unambiguously attributed to emission from the lowest triplet level centered on the PT ligand; its emission intensity is strongly enhanced at 77 K where lifetimes of 724 and 767 ns are measured for [Ru(PT)(3)](2+) and [Ru(PT)(bpy)(2)](2+), respectively. The two complexes with the NT ligand show no triplet emission as observed for the PT analogues, but only a faint fluorescence signal attributable to negligible amounts of free ligand in solution. Photophysical data are fully rationalized with DFF methods, which always predict that the lowest triplet excited state is centered on the extended phenanthroline ligand in all of the investigated R-II complexes. The estimated energy of the lowest triplet level of the PT-based compounds is in good agreement with the experimental value determined from the phosphorescence spectra. Moreover, the theoretical model rationalizes the lack of phosphorescence for the NT series, because the lowest triplet is estimated to be at 0.97 eV above the ground state (approximate to 1280 nm), where non-radiative deactivations prevail. (C) 2014 Elsevier Ltd. All rights reserved.
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