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Polymerization of 1,3-Butadiene with Catalysts Based on Cobalt Dichloride Complexes with Aminophosphines: Switching the Regioselectivity by Varying the MAO/Co Molar Ratio

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Chinese Journal of Polymer Science 2024年第4期42卷 501-510页

作者： Giovanni Ricci Anna Sommazzi Francesco Masi Alessandra Forni cnr-istituto di Scienze e Tecnologie Molecolari“Giulio Natta”(SCITEC) via A.Corti 1220133MilanoItaly Viale Giovanni XXIII 34 I-28100NovaraNOItaly Via Galvani 7 I-26866Sant’Angelo LodigianoLOItaly cnr-istituto di Scienze e Tecnologie Molecolari“Giulio Natta”(SCITEC) via C.Golgi 1920133MilanoItaly

Several novel cobalt dichloride complexes with amino-phosphine bidentate ligands were synthesized and characterized.For some of them single crystals were obtained and their molecular structure was determined by X-ray diffraction method.All the complexes were then used in combination with MAO for the polymerization of 1,3-butadiene,obtaining polymers with different structures(i.e.,predominantly 1,2 or cis-1,4)mainly depending on the type of ligand and on the MAO/Co molar ratio.The behavior of these novel catalysts was compared with that exhibited,in the polymerization of the same monomer,by the systems CoCl_(2)(PR3)2-MAO and CoCl_(2)(PRPh2)2-MAO(R=alkyl or cycloalkyl group),and by the systems based on cobalt dichloride complexes with various bi-and tridentate ligands(e.g.,diphosphines,bis-imines,pyridyl-imines,bis-iminopyridines).The comparison between the different systems allowed us to make some clarity about the actual and effective role played by the various types of ligands in the polymerization of conjugated dienes with catalytic systems CoCl_(2)(L)-MAO,in which L=mono-,bi-,or tri-dentate ligand.

关键词： 1,3-Butadiene Stereospecific polymerization Cobalt catalysts Regioselectivity Aminophosphine ligands Crystal structures Chelate rings

Metal-Halide Perovskite Submicrometer-Thick Films for Ultra-Stable Self-Powered Direct X-Ray Detectors

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Nano-Micro Letters 2024年第9期16卷 410-431页

作者： Marco Girolami Fabio Matteocci Sara Pettinato Valerio Serpente Eleonora Bolli Barbara Paci Amanda Generosi Stefano Salvatori Aldo Di Carlo Daniele M.Trucchi cnr‑ISM Consiglio Nazionale delle RicercheIstituto di Struttura della MateriaSede Secondaria di MontelibrettiDiaTHEMA LabStrada Provinciale 35D900010 MontelibrettiRomeItaly CHOSE–Centre for Hybrid and Organic Solar Energy Department of Electronic EngineeringUniversity of Rome“Tor Vergata”Via del Politecnico 100133 RomeItaly Faculty of Engineering Universita degli Studi Niccolo CusanoVia don Carlo Gnocchi 300166 RomeItaly SpecXLab CNR‑ISMConsiglio Nazionale Delle RicercheIstituto di Struttura Della MateriaArea della Ricerca di Tor VergataVia del Fosso del Cavaliere 10000133 RomeItaly

Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.

关键词： Metal-halide perovskite thin films Direct X-ray detectors Self-powered devices Operational stability Medical linear accelerator

Laser-optimized Pt-Y alloy nanoparticles embedded in Pt-Y oxide matrix for high stability and ORR electrocatalytic activity

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Journal of Energy Chemistry 2024年第5期92卷 508-520页

作者： Riccardo Brandiele Andrea Guadagnini Mattia Parnigotto Federico Pini Vito Coviello Denis Badocco Paolo Pastore Gian Andrea Rizzi Andrea Vittadini Daniel Forrer Vincenzo Amendola Christian Durante Department of Chemical Sciences University of PaduaVia Marzolo 135131 PadovaItaly istituto di Chimica della Materia Condensata e di Tecnologie per l’Energia ICMATE-cnr via Marzolo 1 I-35131 PadovaItaly

The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday technology.While nanostructured Pt catalysts are to date the best available systems in terms of activity,the same is not true for stability,particularly under operating conditions.In this work,Pt_(Х)Y alloy nanoparticles are proposed as active and durable electrocatalysts for ORR.Pt_(Х)Y nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in liquid.The novel integrated laser-assisted methodology succeeded in producing Pt_(Х)Y nanoparticles with the ideal size(1000 A g^(-1).At the same time,the nanoalloys are embedded in a fine Pt oxide matrix,which allows a greater stability of the catalyst than the commercial Pt reference,as directly verified on a gas diffusion electrode.

关键词： Electrocatalysis GDE ORR Pt_(2)Y Pt_(3)Y LAL LFL Oxide support Pto Nanoalloys

A novel 2D-GO@WS2 electrochemical platform for the determination of thiram fungicide

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Journal of Environmental Sciences 2024年第2期136卷 226-236页

作者： Khouloud Abid Daniela Iannazzo Consuelo Celesti Amani Khaskhoussi Antonino Foti Ramzi Maalej Pietro Giuseppe Gucciardi Giovanni Neri Department of Engineering University of MessinaC.da Di DioI-98166 MessinaItaly INSTM Research Unity of MessinaItaly Laboratory of Dielectric and Photonic Materials Faculty of Sciences of SfaxSfaxUniversitySfax 3018Tunisia cnr IPCF istituto per i Processi Chimico-Fisici viale F.Stagno D’Alcontres 37I-98156 MessinaItaly

In this paper,the determination of Thiram fungicide by a novel modified screen-printed carbon electrode(SPCE)fabricated modifying the working electrode(WE)with 2D-GO/WS2nanohybrid composites,is reported.Scanning electron microscopy(SEM),Raman spectroscopy,and fluorescence analysis(PL)were used to reveal the morphological and microstructural characteristics of the 2D-GO/WS2 nanohybrids with different graphene oxide:tungsten disulphide(GO:WS_(2))ratio.Electrochemical characterization demonstrated that the 2D-WS2/GO nanohybrids having a GO:WS_(2)ratio=2:1 shows the highest electrocatalytic activity towards oxidation of Thiram.The developed sensor permits the quantification of Thiram in the linear range 0.083-0.33μM with a limit of detection(LOD)of 0.02μM,which is below the legal limits for this fungicide in drinking water or foods.

关键词： WS_(2)nanosheets Graphene Oxide(GO) Electrochemical sensor Fungicides Thiram

The formation and growth mechanisms of young back-arc spreading ridges from high-resolution bathymetry:The Marsili Seamount(Tyrrhenian Sea,Italy)

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Geoscience Frontiers 2024年第1期15卷 325-338页

作者： Eugenio Nicotra Salvatore Passaro Guido Ventura Dipartimento di Biologia Ecologia e Scienze della Terra Universitàdella Calabria87036 Arcavacata di RendeCosenzaItaly istituto di Scienze Marine cnr 80133 NapoliItaly istituto Nazionale di Geofisica e Vulcanologia 00143 RomaItaly istituto per lo Studio degli impatti Antropici e Sostenibilitáin ambiente marino cnr 91026 Capo GranitolaTrapaniItaly

The formation and growth mechanisms of Mid-Ocean Ridges(MOR)are relatively well known,whereas those of back-arc spreading ridges are comparatively less known because geophysical,geochemical,and morphological data are scarce and of low density.Here we present a high-resolution bathymetry of the Marsili Seamount(MS;1 Ma-3 ka),which represents the inflated spreading ridge of the 2 Ma old Marsili back-arc basin associated to the subduction of the Ionian Sea below the Calabrian Arc and Tyrrhenian Sea.MS is 70 km long,30 km wide,and its height reaches about 3000 m from surrounding seafloor.Our new digital bathymetric model has a 5 m grid cell size resolution and covers the MS bathymetry from-1670 mbsl to the top at-491 mbsl.We conduct morphometric and morphological analyses of the bathymetry and recognize landforms due to volcanic,tectonic,hydrothermal and gravity processes.MS consists of volcanoes related to fissural and central-type activity,this latter located at the northern and southern tips of the main dike swarms.Dike swarms represent the surface expression of different ridge segments whose strikes are controlled by the larger scale back-arc spreading processes and by the local occurrence of an active hydrothermal field.This latter develops in a flat area between two partly overlapping ridge segments where historical volcanism and extensional processes concentrate.Such ridges represent the embryonic stage of the formation of transform-like faults.Central volcanoes,the northern of which is characterized by a caldera,form at the tips of MS because the decrease in width of the major volcanic fissures promotes vent localization associated with the formation of sill-like reservoirs from which central-type vents may develop.Gravity processes affecting the MS flanks are due to shallow seafloor sliding.Caldera collapses affecting the northernmost central-type polygenic volcano must be included in the evaluation of the hazard related to potential tsunami.Inward dipping faults characterize the MS eastern flank suggesting

关键词： Back-arc spreading ridge Morphology Tectonics Volcanism Marsili seamount

Lattice Boltzmann Modeling of Cholesteric Liquid Crystal Droplets Under an Oscillatory Electric Field

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Communications in Computational Physics 2023年第1期33卷 118-143页

作者： F.Fadda A.Lamura A.Tiribocchi Institute of Physics University of Amsterdam1098 XH AmsterdamThe Netherlands Department of Chemical Engineering Kyoto UniversityKyoto 615-8510Japan Dipartimento di Fisica and Sezione INFN Universit`a di BariVia Amendola 17370126 BariItaly istituto applicazioni calcolo CNRVia Amendola 122/D70126 BariItaly istituto applicazioni calcolo cnr via dei Taurini 1900185 RomeItaly

We numerically study the dynamics of quasi-two dimensional cholesteric liquid crystal droplets in the presence of a time-dependent electric field,rotating at constant angular velocity.A surfactant sitting at the droplet interface is also introduced to prevent droplet coalescence.The dynamics is modeled following a hybrid numerical approach,where a standard lattice Boltzmann technique solves the Navier-Stokes equation and a finite difference scheme integrates the evolution equations of liquid crystal and surfactant.Our results show that,once the field is turned on,the liquid crystal rotates coherently triggering a concurrent orbital motion of both droplets around each other,an effect due to the momentum transfer to the surrounding fluid.In addition the topological defects,resulting from the conflict orientation of the liquid crystal within the drops,exhibit a chaotic-like motion in cholesterics with a high pitch,in contrast with a regular one occurring along circular trajectories observed in nematics drops.Such behavior is found to depend on magnitude and frequency of the applied field as well as on the anchoring of the liquid crystal at the droplet interface.These findings are quantitatively evaluated by measuring the angular velocity of fluid and drops for various frequencies of the applied field.

关键词： Lattice Boltzmann simulations liquid crystals non-Newtonian fluids

Distinct vibrational signatures and complex phase behavior in metallic oxygen

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Matter and Radiation at Extremes 2024年第2期9卷 4-11页

作者： Philip Dalladay-Simpson Bartomeu Monserrat Li Zhang Federico Gorelli Center for High Pressure Science Technology Advanced Research 1690 Cailun RoadShanghai 201203China Department of Materials Science and Metallurgy University of Cambridge27 Charles Babbage RoadCambridge CB3 OFSUnited Kingdom Cavendish Laboratory University of CambridgeJ.J.Thomson AvenueCambridge CB3 OHEUnited Kingdom istituto Nazionale di Ottica Consiglio Nazionale delle Ricerche(CNR-INO)50125 FlorenceItaly Shanghai Advanced Research in Physical Sciences(SHARPS) ShanghaiChina

Evidence for metallization in dense oxygen has been reported for over 30 years[Desgreniers et al.,J.Phys.Chem.94,1117(1990)]at a now routinely accessible 95 GPa[Shimizu et al.,Nature 393,767(1998)].However,despite the longevity of this result and the technological advances since,the nature of the metallic phase remains poorly constrained[Akahama et al.,Phys.Rev.Lett.74,4690(1995);Goncharov et al.,Phys.Rev.B 68,224108(2003);Ma,Phys.Rev.B 76,064101(2007);and Weck et al.,Phys.Rev.Lett.102,255503(2009)].In this work,through Raman spectroscopy,we report the distinct vibrational characteristics of metallicζ-O_(2) from 85 to 225 GPa.In comparison with numerical simulations,weﬁnd reasonable agreement with the candidate structure up to about 150 GPa.At higher pressures,the C2/mstructure is found to be unstable and incompatible with experimental observations.Alternative candidate structures,and Ci,with C2/m C2/conly two molecules in the primitive unit cell,are found to be stable and more compatible with measurements above 175 GPa,indicative of the dissociation of(O_(2))4 units.Further,we report and discuss a strong hysteresis and metastability with the precursory phaseϵ-O_(2).Theseﬁndings will reinvigorate experimental and theoretical work into the dense oxygen system,which will have importance for oxygen-bearing chemistry,prevalent in the deep Earth,as well as fundamental physics.

关键词： metallic phase vibrational

Polydopamine-coated photoautotrophic bacteria for improving extracellular electron transfer in living photovoltaics

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Nano Research 2024年第2期17卷 866-874页

作者： Melania Reggente Charlotte Roullier Mohammed Mouhib Patricia Brandl Hanxuan Wang Stefano Tacconi Francesco Mura Luciana Dini Rossella Labarile Massimo Trotta Fabian Fischer Ardemis A.Boghossian Institute of Chemical Sciences and Engineering(ISIC) Ecole Polytechnique Fédérale de Lausanne(EPFL)Lausanne 1015Switzerland Department of Biology and Biotechnology Charles Darwin Sapienza University of RomeRome 00185Italy Research Center on Nanotechnology Applied for Engineering of Sapienza(CNIS) University of Rome SapienzaRome 00185Italy cnr-IPCF Consiglio Nazionale delle Ricerche–istituto per i Processi Chimico Fisici Bari 70126Italy Institute of Life Technologies HES-SO Valais-WallisSion 1950Switzerland Institute for Renewable Energy HES-SO Valais-WallisSion 1950Switzerland

Living photovoltaics are microbial electrochemical devices that use whole cell–electrode interactions to convert solar energy to electricity.The bottleneck in these technologies is the limited electron transfer between the microbe and the electrode surface.This study focuses on enhancing this transfer by engineering a polydopamine(PDA)coating on the outer membrane of the photosynthetic microbe Synechocystis sp.PCC6803.This coating provides a conductive nanoparticle shell to increase electrode adhesion and improve microbial charge extraction.A combination of scanning electron microscopy(SEM),transmission electron microscopy(TEM),UV–Vis absorption,and Raman spectroscopy measurements were used to characterize the nanoparticle shell under various synthesis conditions.The cell viability and activity were further assessed through oxygen evolution,growth curve,and confocal fluorescence microscopy measurements.The results show sustained cell growth and detectable PDA surface coverage under slightly alkaline conditions(pH 7.5)and at low initial dopamine(DA)concentrations(1 mM).The exoelectrogenicity of the cells prepared under these conditions was also characterized through cyclic voltammetry(CV)and chronoamperometry(CA).The measurements show a three-fold enhancement in the photocurrent at an applied bias of 0.3 V(vs.Ag/AgCl[3 M KCl])compared to non-coated cells.This study thus lays the framework for engineering the next generation of living photovoltaics with improved performances using biosynthetic electrodes.

关键词： biophotovoltaics bioelectronics photosynthetic bacteria cyanobacteria polydopamine adherence

Marine propellers performance and flow-field prediction by a free-wake panel method

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Journal of Hydrodynamics 2014年第5期26卷 780-795页

作者： GRECO Luca MUSCARI Roberto TESTA Claudio DI MASCIO Andrea cnr-INSEAN Italian Ship Model BasinRomeItaly cnr-IAC Istituto per le Applicazioni del Calcolo "M. Picone"RomeItaly

A Boundary Element Method （BEM） hydrodynamics combined with a flow-alignment technique to evaluate blades shed vorticity is presented and applied to a marine propeller in open water. Potentialities and drawbacks of this approach in capturing propeller performance, slipstream velocities, blade pressure distribution and pressure disturbance in the flow-field are highlighted by comparisons with available experiments and RANSE results. In particular, correlations between the shape of the convected vortex- sheet and the accuracy of BEM results are discussed throughout the paper. To this aim, the analysis of propeller thrust and torque is the starting point towards a detailed discussion on the capability of a 3-D free-wake BEM hydrodynamic approach to describe the local features of the flow-field behind the propeller disk, in view of applications to propulsive configurations where the shed wake plays a dominant role.

关键词： BEM hydrodynamics free-wake analysis BEM-RANSE comparison