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Light electrospun Polyvinylpyrrolidone Blanket for Low Frequencies Sound Absorption

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Chinese Journal of Polymer Science 2018年第12期36卷 1368-1374页

作者： Joshua Avossa Francesco Brand Francesco Marulo Giuseppe Petrone Stefano Guido Giovanna Tomaiuolo Aniello Costantini dipartimento di ingegneria chimica dei Materiali e della Produzione lndustriale (DICMaPI) Universitgt degli Studi di Napoli Federico II Napoli Italy dipartimento di lngegneria Industriale (diI) Universita degli Studi di Napoli Federico II Napoli Italy

Light polymeric soundproofing materials （density = 63 kg/m3） of interest for the transportation industry were fabricated through electrospinning. Blankets of electrospun polyvinylpyrrolidone （average fiber diameter = （1.6 ± 0.5） or （2.8 ± 0.5） μm） were obtained by stacking disks of electrospun mats. The sound absorption coefficients were measured using the impedance tube instrument based on ASTM e1050 and ISO 10534-2. For a given set of disks （from a minimum of 6） the sound absorption coefficient changed with the frequency （in the range 200-1600 Hz） following a bell shape curve with a maximum （where the coefficient is greater than 0.9） that shifts to lower frequencies at higher piled disks number and greater fiber diameter. This work showed that electrospinning produced sound absorbers with reduced thickness （2-3 cm） and excellent sound-absorption properties in the low and medium frequency range.

关键词： electrospinning Polyvinylpyrrolidone (PVP) Sound absorption Impedance tube

Application of flame-formed carbon nanoparticle films for ethanol sensing Author links open overlay panel

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Particuology 2024年第8期91卷 202-210页

作者： Pegah Darvehi Luca Basta Mario Commodo Patrizia Minutolo Andrea D'Anna Istituto di Scienze e Tecnologie per l’energia e la MobilitàSostenibili Consiglio Nazionale delle RicercheP.le Tecchio 8080125NapoliItaly dipartimento di ingegneria chimica dei Materiali e della Produzione IndustrialeUniversitàdegli Studi di Napoli Federico IIP.le Tecchio 8080125NapoliItaly

Carbon nanoparticles(CNPs)have received considerable attention due to their exceptional qualities and *** unique physical and chemical characteristics make them extremely intriguing as materials for numerous high-potential applications,such as electronics and gas *** study focused on producing carbon-based nanomaterial devices by deposition of flame-formed carbon nanoparticles on a suitable substrate and investigating their gas-sensing *** were produced in a fuel-rich laminar premixed ethylene/air flame and the collected CNP film was morphologically and electrically *** electrical conductivity of the film was investigated as a function of ethanol concentration and amount of deposited ***,CNP films exhibited high sensitivity to ambient ethanol gas concentrations,and rapid recovery times at room temperature,and showed a sensitivity increasing with the amount of deposited material and the surface *** findings demonstrate the high potential of combustion-generated CNPs as building materials for low-cost and portable ethanol sensors.

关键词： Flame synthesis Carbon nanoparticles Soot Nanostructured thin film Optical and electrical characterization Atomic force microscopy Sensors

Corrosion Behaviour of Zr-Ag Alloys for Dental Implant Application

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Materials Sciences and Applications 2023年第11期14卷 501-514页

作者： Francesco Rosalbino Daniele Macciò Giorgio Scavino dipartimento di scienza dei materiali e ingegneria chimica (diCHI) Politecnico di Torino Torino Italy dipartimento di chimica e chimica Industriale (DCCI) Università Degli Studi di Genova Genova Italy

The electrochemical corrosion behaviour of three Zr-Ag alloys (Zr-1Ag, Zr-3Ag and Zr-5Ag) was investigated. Open circuit potential, linear potentiodynamic polarization and electrochemical impedance spectroscopy (eIS) techniques were employed in aerated artificial saliva (pH = 4.0) at 37°C. Silver alloying additions are found to be effective in enhancing the corrosion resistance of zirconium in artificial saliva environment. In fact, Zr-Ag alloys exhibit higher open circuit potentials, larger breakdown potentials and higher impedance values as compared to cp Zr. This behaviour can be ascribed to the formation of a thicker and more stable passive film with increasing compactness, able to provide better protection against the corrosion attack.

关键词： Zr-Ag Alloys Corrosion Resistance Open Circuit Potential Potentiodynamic Polarization Curves electrochemical Impedance Spectroscopy (eIS)

Quantitative imaging of the complexity in liquid bubbles’evolution reveals the dynamics of film retraction

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Light(Science & Applications) 2019年第1期8卷 1021-1032页

作者： Biagio Mandracchia Zhe Wang Vincenzo Ferraro Massimiliano Maria Villone ernesto di Maio Pier Luca Maffettone Pietro Ferraro CNR-ISASI Istituto di Scienze Applicate e Sistemi Intelligenti“E.Caianiello”del CNRVia Campi Flegrei 3480078 PozzuoliNapoliItaly College of Applied Sciences Beijing University of Technology100124 BeijingChina dipartimento di ingegneria chimica dei Materiali e della Produzione IndustrialeUniversita di Napoli FedericoⅡPiazzale Tecchio 8080125 NapoliItaly

The dynamics and stability of thin liquid films have fascinated scientists over many *** film flows are central to numerous areas of engineering,geophysics,and biophysics and occur over a wide range of lengths,velocities,and liquid property *** spite of many significant developments in this area,we still lack appropriate quantitative experimental tools with the spatial and temporal resolution necessary for a comprehensive study of film *** propose tackling this problem with a holographic technique that combines quantitative phase imaging with a custom setup designed to form and manipulate *** results,gathered on a model aqueous polymeric solution,provide unparalleled insight into bubble dynamics through the combination of a full-field thickness estimation,threedimensional imaging,and a fast acquisition *** unprecedented level of detail offered by the proposed methodology will promote a deeper understanding of the underlying physics of thin film dynamics.

关键词： film dynamics liquid

The effect of humidity on the CO_2/N_2 separation performance of copolymers based on hard polyimide segments and soft polyether chains:experimental and modeling

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Green energy & environment 2016年第3期1卷 201-210页

作者： Luca Olivieri Alberto Tena Maria Grazia De Angelis Antonio Hernández Giménez Angel e.Lozano Giulio Cesare Sarti dipartimento di ingegneria Civile chimica Ambientale e dei materiali Alma Mater Studiorum-Università di Bologna SMAP UA UVA-CSIC Universidad de Valladolid Facultad de Ciencias Real de Burgos s/n Helmholtz-Zentrum Geesthacht Institute of Polymer Research Instituto de Ciencia y Tecnología de Polímeros CSIC

In this work, we studied two copolymers formed by segments of a rubbery polyether（PPO or PeO） and of a glassy polyimide（BPDA-ODA or BKDA-ODA） suitable for gas separation and CO2 capture. Firstly, we assessed the absorption of water vapor in the materials, as a function of relative humidity（R.H.）, finding that the humidity uptake of the copolymers lies between that of the corresponding pure homopolymers ***, we studied the effect of humidity on CO2 and N2 permeability, as well as on CO2/N2 selectivity, up to R.H. of 75%. The permeability decreases with increasing humidity, while the ideal selectivity remains approximately constant in the entire range of water activity investigated. The humidity-induced decrease of permeability in the copolymers is much smaller than the one observed in polyimides such as Matrimid? confirming the positive effect of the polyether phase on the membrane ***, we modeled the humidity-induced decrease of gas solubility, diffusivity and, consequently, permeability, using a suitable approach that considers the free volume theory for diffusion and LF model for solubility. Such model allows estimating the extent of competition that the gases undergo with water during sorption in the membranes, as a function of the relative humidity, as well as the expected reduction of free volume by means of water molecules occupation and consequent reduction of diffusivity.

关键词： CO2 capture Humid gas permeation Transport properties in polymeric membranes Water vapor sorption Modeling

Dehydration of plant cells shoves nuclei rotation allowing for 3D phase-contrast tomography

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Light(Science & Applications) 2021年第10期10卷 1889-1904页

作者： Zhe Wang Vittorio Bianco Daniele Pirone Pasquale Memmolo Massimiliano Maria Villone Pier Luca Maffettone Pietro Ferraro dipartimento di ingegneria chimica dei materiali e della Produzione Industriale Universitàdegli Studi di Napoli“Federico II”Piazzale Tecchio 8080125 NapoliItaly NeAPoLIS Numerical and Experimental Advanced Program on Liquids and Interface SystemsJoint Research Center CNR-Universitàdegli Studi di Napoli“Federico II”NapoliItaly CNR-ISASI Institute of Applied Sciences and Intelligent Systems“E.Caianiello”Via Campi Flegrei 3480078 PozzuoliNapoliItaly dipartimento di ingegneria elettrica e delle Tecnologie dell’Informazione Universitàdegli Studi di Napoli“Federico II”via Claudio 2180125 NapoliItaly

Single-cell phase-contrast tomography promises to become decisive for studying 3D intracellular structures in *** involves probing cells with light at wide angles,which unfortunately requires complex *** we show an intriguing concept based on an inherent natural process for plants biology,i.e.,dehydration,allowing us to easily obtain 3D-tomography of onion-epidermal cells’*** fact,the loss of water reduces the turgor pressure and we recognize it induces significant rotation of cells’*** to the holographic focusing flexibility and an ad-hoc angles’tracking algorithm,we combine different phase-contrast views of the nuclei to retrieve their 3D refractive index *** identification capability and a strategy for measuring morphology,dry mass,biovolume,and refractive index statistics are reported and *** new concept could revolutionize the investigation in plant biology by enabling dynamic 3D quantitative and label-free analysis at sub-nuclear level using a conventional holographic setup.

关键词： rotation holographic phase

experimental characterization and CFD simulation of gas maldistribution in turbulent fluidization of Group A particles

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Particuology 2023年第11期82卷 192-203页

作者： Maurizio Troiano Benjamin Amblard Sina Tebianian Roberto Solimene Piero Salatino Thierry Gauthier dipartimento di ingegneria chimica dei Materiali e della Produzione IndustrialeUniversitàdegli Studi di Napoli Federico IIPiazzale Vincenzo Tecchio 8080125NapoliItaly IFP energies nouvelles Rond-point de l'échangeur de Solaize BP 369360SolaizeFrance Istituto di Scienze e Tecnologie per l’energia e la MobilitàSostenibili(STeMS) Consiglio Nazionale delle Ricerche(CNR)Piazzale Vincenzo Tecchio 8080125NapoliItaly

The study presented hereby investigates experimentally and with CFD simulations the gas distribution effect on the hydrodynamic of a Geldart Group A turbulent fluidized bed. experiments were carried out on a cold flow fluidized bed column with an even and uneven gas distribution. Local solid volume fraction profiles were measured using optical probes at different bed heights and along two radial directions. Optical probe measurements allow catching a clear hydrodynamic difference between both even and uneven gas distributions. These results were then used to assess CFD simulations with the code Barracuda^(TM) (MP-PIC approach). It is noteworthy that the choice of drag correlation and boundary conditions strongly influences the agreement between the experimental and CFD results. Once the correct parameters are chosen, CFD simulations captured the effect of gas distribution changes.

关键词： Characterization of multiphase reactors Fluidized bed Turbulent Gas distribution Jet Optical probe CFD simulations

Functional group resolved NMR relaxation of 3-carbon adsorbates in mesoporous alumina

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Magnetic Resonance Letters 2023年第3期3卷 248-255,I0004页

作者： Neil Robinson Carmine D’Agostino Michael LJohns Department of Chemical engineering The University of Western Australia35 Stirling HighwayPerthWA 6009Australia Department of Chemical engineering The University of ManchesterOxford RoadManchesterM139PLUK dipartimento di ingegneria Civile ChimicaAmbientale e Dei Materiali(DICAM)Alma Mater Studiorum e Universita di BolognaVia Terracini28Bologna40131Italy

NMR relaxation analysis provides a unique and non-invasive probe of fluid dynamics within porous materials,and may be applied to the interpretation of a wide variety of material and interfacial ***,we report two-dimensional^(1)H T_(1)-T_(2)relaxation correlation measurements of a range of three-carbon adsorbates(1-propanol,2-propanol and propanoic acid)imbibed within the mesoporous metal oxide *** data,acquired across field strengths of 2 MHz,12.7 MHz and 43 MHz,clearly reveal two populations in each measurement,identified as the alkyl and hydroxyl moieties of each *** results expand the range of materials in which such functional group resolved relaxation is known to occur,and demonstrate the clear persistence of such phenomena using a range of typical benchtop NMR systems employed to study fluid-saturated porous media.

关键词： NMR relaxation Adsorption Porous media Low-field NMR

efficient hexane isomers separation in isoreticular bipyrazolate metal-organic frameworks:The role of pore functionalization

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Nano Research 2021年第2期14卷 532-540页

作者： Rebecca Vismara Corrado di Nicola Rodrigo Gil-San Millan Kostiantyn V.Domasevich Claudio Pettinari Jorge A.R.Navarro Simona Galli dipartimento di scienza e Alta Tecnologiay University delVInsubria 22100 ComoItaly School of Science and Technology University ofCamerino62032 Camerino(MC)Italy Departamento de Quimica Inorganica Universidad de Granada18071 GranadaSpain Taras Shevchenko National University of Kyiv 01601 KyivUkraine School of Pharmacy University of Camerino62032 Camerino(MC)Italy Istituto di chimica dei Composti Organometallici(ICCOM-CNR) 50019 Sesto FiorentinoItaly Consorzio Interuniversitario Nazionale per la scienza e Tecnologia dei materiali 50121 FirenzeItaly Department of Chemistry University of LiverpoolLiverpool L73NYUK

Hydrocarbons separation in petrochemical industries is a key,energy-consuming stage in the manufacture of high-quality added-value products—hence the need for more efficient materials and environmentally friendly methodologies to improve this *** this context,we have studied the effect of metal-organic frameworks(MOFs)pore functionalization in hexane isomers separation,isolating the robust isoreticular zinc(ll)bipyrazolates Zn(BPZ),showing no pore decoration,Zn(Me_(2)BPZ),the pores of which are decorated with apolar methyl groups,and Zn(BPZ(NH_(2))_(2)),the spacers of which possess polar Lewis-basic functions(H_(2)BPZ=1H,1'H-4,4'-bipyrazole;H_(2)Me_(2)BPZ=3,3'-dimethyl-1H,1'H-4,4'-bipyrazole;H_(2)BPZ(NH_(2))_(2)=3,5-diamino-1H,1'H-4,4'-bipyrazole;DMF=dimethylformamide).After characterizing Zn(BPZ(NH_(2))_(2))as per its crystal structure and thermal behaviour,and all the three MOFs as per their textural properties,we investigated,from the experimental and computational points of view,the impact of the square one-dimensional channels decoration on the separation of the hexane isomers,demonstrating the relevance of pore constrictions in the resolution of the title alkanes mixture.

关键词： adsorption molecular sieving nitrogen-donor ligands gas separation pow der diffraction variable-tem perature pulse gas chromatography