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A new mechanical dry process able to develop nanoparticles coated with polymeric material is proposed. An opportunely developed pilot ball milling apparatus permitted to catch-up significant process parameters that are here reported. A... more
A new mechanical dry process able to develop nanoparticles coated with polymeric material is proposed. An opportunely developed pilot ball milling apparatus permitted to catch-up significant process parameters that are here reported. A proper analysis of the obtained parameters permitted to individuate optimized milling conditions and to prepare a magnetite/albumin core/shell nanocomposite, material with a potential wide spread of applications in biomedical fields. The obtained powder consists in particles having a diameter of about 45 nm and exhibits a high morphological homogeneity. The proposed method is facile, low cost, solvent free and is applicable to the development of a broad range of multifunctional composites for biomedical applications.
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The required application of ceramic coatings on metallic interconnects to avoid corrosion in SOFC oxidizing environment has pointed out the need to find cheap and environmental friendly approaches for the production of coating powders, to... more
The required application of ceramic coatings on metallic interconnects to avoid corrosion in SOFC oxidizing environment has pointed out the need to find cheap and environmental friendly approaches for the production of coating powders, to be applied by diffused and cost effective wet powder processing techniques like spray and slurry coating methods. High Energy Ball Milling (HEBM) is a mechanochemical powder processing technique here exploited to produce mixed composition coating precursor powders from Mn and Co oxides. The processed compound consists in nanostructured and intimately mixed Mn-Co oxides that rapidly react to produce the high temperature spinel phase during the sintering process. A slurry suspension was formulated and applied on a stainless steel substrate, evaluating the coating behaviour during 500h oxidation test at 800°C by means of Area Specific Resistance (ASR) evolution, X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses.
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Magnetic porous metal-organic framework nanocomposite was obtained by an easy, efficient, and environmentally friendly fabrication method. The material consists in magnetic spinel iron oxide nanoparticles incorporated in an iron(III)... more
Magnetic porous metal-organic framework nanocomposite was obtained by an easy, efficient, and environmentally friendly fabrication method. The material consists in magnetic spinel iron oxide nanoparticles incorporated in an iron(III) carboxylate framework. The magnetic composite was fabricated by a multistep mechanochemical approach. In the first step, iron oxide nanoparticles were obtained via ball milling inducing mechanochemical reaction between iron chlorides and NaOH using NaCl as dispersing agent. Magnetic nanoparticles (MNs) were functionalized by neat grinding with benzene-1,3,5-tricarboxylic acid (1, 3, 5 BTC) and were then subjected to liquid assisted milling using hydrated FeCl3, water, and ethanol to obtain a magnetic framework composite (MFC) consisting of iron oxide nanoparticles encapsulated in a MOF matrix. We report, for the first time, the applicability of the grinding method to obtain a magnetic composite of metal-organic frameworks. The synthesized material exhibits magnetic characteristics and high porosity, and it has been tested as carrier for targeted drug delivery studying loading and release of a model drug (doxorubicin). Developed systems can associate therapeutics and diagnostics properties with possible relevant impact for theranostic and personalized patient treatment. Furthermore, the material properties make them excellent candidates for several other applications such as catalysis, sensing, and selective sequestration processes.
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This study is focused on the phase separation phenomena in Fe(Se,Te) materials. In particular, it investigates the effect of a high temperature and long time annealing treatment on morphostructural and superconducting properties of bulk... more
This study is focused on the phase separation phenomena in Fe(Se,Te) materials. In particular, it investigates the effect of a high temperature and long time annealing treatment on morphostructural and superconducting properties of bulk samples. The synthesis of Fe(Se,Te) compounds was carried out through a melting route, and the materials were characterized in their morphostructural and magnetic properties. The obtained compounds possess a high degree of inhomogeneity due to dendritic precipitates of secondary phases in a superconducting tetragonal matrix. The high temperature annealing treatment induces a morphological evolution of the material and leads to the structuration of two distinct superconducting phases.
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ABSTRACT
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Conference code: 88003, Export Date: 30 September 2013, Source: Scopus, Language of Original Document: English, Correspondence Address: Crestini, C.; ENEA, Research Centre Casaccia, via Anguillarese 301, 00123 Rome, Italy; email:... more
Conference code: 88003, Export Date: 30 September 2013, Source: Scopus, Language of Original Document: English, Correspondence Address: Crestini, C.; ENEA, Research Centre Casaccia, via Anguillarese 301, 00123 Rome, Italy; email: crestini@stc.uniroma2.it, References: McKeon, N.B., Budd, P.M., Exploitation of intrinsic microporosity in polymer-based materials (2010) Macromolecules, 43, p. 5163;, Sponsors: Assoc. Chem. Pulp Pap. Chem. Eng. (ZELLCHEMING)
Synthesis of nanocrystalline MnFe2O4 has been carried out by High Energy Ball Milling (HEBM) using MnO and Fe2O3 commercial powders. X ray diffraction technique coupled to Rietveld refinement has been successfully used for monitoring the... more
Synthesis of nanocrystalline MnFe2O4 has been carried out by High Energy Ball Milling (HEBM) using MnO and Fe2O3 commercial powders. X ray diffraction technique coupled to Rietveld refinement has been successfully used for monitoring the advancement of the chemical reaction. Nanoreactors made of nanocrystalline MnFe2O4 and HEBM activated Na2CO3 were tested for the production of hydrogen in the mixed-ferrite water splitting thermochemical cycle. The hydrogen generation rate measured by means of a nanocrystalline mixture was 6 times higher than the one observed using microcrystalline composite.
Concept The last decade has seen growing attention in the synthesis and characterization of crystalline porous metal organic frameworks (MOFs) compounds in virtue of their potential applications in gas storage, separation and... more
Concept The last decade has seen growing attention in the synthesis and characterization of crystalline porous metal organic frameworks (MOFs) compounds in virtue of their potential applications in gas storage, separation and catalysis.[1] Among the different MOFs, the iron(III) 1,3,5-benzene tricarboxylate (Fe-BTC), well known as MIL-100(Fe), is one of most interesting 3D hybrid supertetrahedral structure that displays a hierarchy of microporous (ca. 5.5 and 8.6 Å) and mesoporous (ca. 25 and 29 Å).[2] The usually reported method for MOFs synthesis, including MIL-100(Fe), is the solvothermal one. Unfortunately, the solvothermal method imposes, already at the laboratory scale, hard reaction conditions, i.e. high temperature and pressure, use of large solvent amounts, and long synthesis times. Such reaction conditions would represent a serious drawback in the scale-up of the synthesis. Motivations and Objectives In this study we propose the Liquid-Assisted Grinding (LAG) [3] mechanosy...
ABSTRACT X-ray diffraction line profile analysis has been applied to investigate the early stages of powder amorphization by mechanical alloying (MA) in the Pd80Si20 (at.%) system. In particular, Fourier coefficients analysis has been... more
ABSTRACT X-ray diffraction line profile analysis has been applied to investigate the early stages of powder amorphization by mechanical alloying (MA) in the Pd80Si20 (at.%) system. In particular, Fourier coefficients analysis has been performed to determine, from the large and progressive line broadening, the structural evolution of Pd grains in terms of average size (D) and lattice distortions (G ). A comparison with pure palladium powder samples, milled under the same conditions has been used to analyse better the response of palladium under ball milling. MA induces, on pure palladium, effects 0are similar to conventional cold working. A minimum average size is soon reached after 1 h of MA which depends on the crystallographic direction: ≈ 22/23, ≈ 13/14 (nm). From the unequal peak broadening along the [100] and [111] crystallographic directions, a lattice distortion parameter G = L≈ 2 × 10(nm) (L is a length in the physical space perpendicular to the diffracting planes and is the mean square microstrain) and a deformation and twin faults probability of 1.5α+β ≈ 0.01/0.015 have been estimated. Accounting for planar defects the average grain size is increased to about 35/40 (nm) in both [111] and [100] directions. The microstructure evolution of the Pd80Si20 sample can be interpreted as a two-step process. At the beginning, up to 1 h of MA, the behaviour is similar to pure palladium. Thereafter MA induces a further particle size refinement to about ≈ 3/5(nm), before promoting solid state amorphization. The lattice distortion parameter approaches, after a steep increase, the values measured for pure palladium, so that the crystalline structure destabilization seems to be achieved, in this system, by grain boundary energy storage.
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Summary Kinematic equations describing velocity and acceleration of a ball in a vial of a planetary ball-mill have been derived. The consequent energy transfer from the mill to the system constituted by the powder, the balls and the... more
Summary Kinematic equations describing velocity and acceleration of a ball in a vial of a planetary ball-mill have been derived. The consequent energy transfer from the mill to the system constituted by the powder, the balls and the vials have been evaluated by theoretical-empirical approach. Mixtures of elemental iron and zirconium powders corresponding to the average Fe2Zr composition have been mechanically
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The application of magnetic nanoparticles (MNPs) in medicine is considered much promising especially because they can be handled and directed to specific body sites by external magnetic fields. MNPs have been investigated in magnetic... more
The application of magnetic nanoparticles (MNPs) in medicine is considered much promising especially because they can be handled and directed to specific body sites by external magnetic fields. MNPs have been investigated in magnetic resonance imaging, hyperthermia and drug targeting. In this study, properly functionalized core/shell MNPs with antimicrobial properties were developed to be used for the prevention and treatment of medical device-related infections. Particularly, surface-engineered manganese iron oxide MNPs, produced by a micro-emulsion method, were coated with two different polymers and loaded with usnic acid (UA), a dibenzofuran natural extract possessing antimicrobial activity. Between the two polymer coatings, the one based on an intrinsically antimicrobial cationic polyacrylamide (pAcDED) resulted to be able to provide MNPs with proper magnetic properties and basic groups for UA loading. Thanks to the establishment of acid-base interactions, pAcDED-coated MNPs were able to load and release significant drug amounts resulting in good antimicrobial properties versus Staphylococcus epidermidis (MIC=0.1mg/mL). The use of pAcDED having intrinsic antimicrobial activity as MNP coating in combination with UA likely contributed to obtain an enhanced antimicrobial effect. The developed drug-loaded MNPs could be injected in the patient soon after device implantation to prevent biofilm formation, or, later, in presence of signs of infection to treat the biofilm grown on the device surfaces.
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ABSTRACT The sodium manganese ferrite thermochemical cycle for hydrogen production by water splitting can successfully operate in a relatively low temperature range (1023–1073 K) and has a high potential for coupling with the solar source... more
ABSTRACT The sodium manganese ferrite thermochemical cycle for hydrogen production by water splitting can successfully operate in a relatively low temperature range (1023–1073 K) and has a high potential for coupling with the solar source using conventional structural materials. With the aim of implementing the cycle in a solar reactor, the hydrogen evolution rate from the reactive mixture measured in laboratory apparatus has been modeled by using a shrinking-core model. Such a model proved to adequately describe the rate of hydrogen production in the studied temperature and water concentration range. The model was extended to predict the behavior of the reactive mixture subjected to different experimental conditions.
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ABSTRACT The sodium manganese mixed ferrite thermochemical cycle Na(Mn1/3Fe2/3)O2/(MnFe2O4 + Na2CO3) for sustainable hydrogen production has been implemented in a solar reactor-receiver, packed with indirectly heated MnFe2O4/Na2CO3... more
ABSTRACT The sodium manganese mixed ferrite thermochemical cycle Na(Mn1/3Fe2/3)O2/(MnFe2O4 + Na2CO3) for sustainable hydrogen production has been implemented in a solar reactor-receiver, packed with indirectly heated MnFe2O4/Na2CO3 mixture pellets, with the aim of verifying its feasibility and of determining the critical aspects of the process. The reactor operates at nearly constant temperature in the range 750–800 °C; the shift between the hydrogen-producing and regeneration steps is obtained by switching the reactive gas from water to carbon dioxide. Hydrogen produced during 1-h operation of the reactor is in the range of 130–460 μmol/g of mixture, depending on experimental conditions. Compared to other existing prototypes, the implemented process obtains comparable production efficiencies while operating at lower temperature both in the hydrogen production and regeneration phases.
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ABSTRACT In the present work preliminary characterization tests, finalized to application as a residential micro-CHP system, are reported. Through systematic, parallel testing under predetermined conditions, laboratories at ENEA and the... more
ABSTRACT In the present work preliminary characterization tests, finalized to application as a residential micro-CHP system, are reported. Through systematic, parallel testing under predetermined conditions, laboratories at ENEA and the University of Perugia aim at establishing the real lifetime expectancy and performance characteristic of 1 kW-class SOFC stacks fed with natural gas from the grid, downstream of a specifically developed desulphurizer for the abatement of odorants. Through the assessment of material response and delivered power also at single cell level, it will be possible to establish and improve the behaviour in time of a SOFC system operated under realistic conditions. There is continuous feedback with both the system optimization engineers as with powder development chemists, in order to bring the concept swiftly and efficiently to market maturity, as well as prepare the basis for second generation systems with improved stack performance and durability.
Research Interests: Nanomedicine, Nanotechnology, Manganese, Diffusion, Mice, and 14 moreFemale, Animals, Colloids, Mechanical Stress, Solutions, Survival Rate, Lethal Dose, Materials Testing, Drug Compounding, Cell Survival, Magnetite Nanoparticles, Contrast Media, Tissue distribution, and Pharmacology and pharmaceutical sciences
ABSTRACT In the frame of an activity oriented on the development and characterization of cells and stacks for the integration in a micro-CHP system, synthesis, formulation and optimization of manganese cobalt spinel for the deposition of... more
ABSTRACT In the frame of an activity oriented on the development and characterization of cells and stacks for the integration in a micro-CHP system, synthesis, formulation and optimization of manganese cobalt spinel for the deposition of protective coatings on interconnector plates have been performed. A description of the process is given. Characterization of spray coated interconnector samples and discussion of the experimental findings are reported.
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Improvement of mechanical properties of recycled mixed plastic waste is one of the fundamental goals in any recycling process. However, polymer immiscibility makes the development of any effective reprocessing method difficult. In this... more
Improvement of mechanical properties of recycled mixed plastic waste is one of the fundamental goals in any recycling process. However, polymer immiscibility makes the development of any effective reprocessing method difficult. In this work, a polymer milling process with liquid CO2 was applied to polymeric mixed waste, obtaining a powder material which was successfully utilized as a matrix for a new composite material. Developed materials have interesting mechanical properties and material performance can easily be improved. Investigations on selected mixtures of PP and PE clearly showed evidence of chemical compatibilization.
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ABSTRACT Verification of the feasibility of the thermochemical two-step water-splitting cycle based on using mixed sodium–manganese ferrite is reported. Oxygen releasing and regeneration of the initial reactants (MnFe 2 O 4 and Na 2 CO 3)... more
ABSTRACT Verification of the feasibility of the thermochemical two-step water-splitting cycle based on using mixed sodium–manganese ferrite is reported. Oxygen releasing and regeneration of the initial reactants (MnFe 2 O 4 and Na 2 CO 3) was performed under different experimental conditions. A temperature/P CO 2 region in which the stoichiometric regeneration of initial reactants was achieved and the whole cyclability diagram is reported. Thermochemical water-splitting cycles have huge potential as an environmentally friendly approach to producing hydrogen. In fact, all the chemicals involved in the processes are recycled and water is the only re-quired input. Furthermore, concentrated solar radiation can furnish the heat necessary to perform one or all the reactions taking part in the cycle [1–3]. The two step water-splitting system that utilizes sodium–manganese ferrite was initially proposed by Tamaura et al. [4] and can be written according to the following equations: 2MnFe 2 O 4 ðsÞ þ 3Na 2 CO 3 ðsÞ þ H 2 O ¼ 6NaðMn 1=3 Fe 2=3 ÞO 2 ðsÞ þ 3CO 2 ðgÞ þ H 2 ð1Þ
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The iodine number furnishes surface area values in disagreement with the NSA technique in the case of disordered carbon i.e., lower than NSA in case of high oxygen content (more than 2%), but higher for low oxygen content (less than 1%).... more
The iodine number furnishes surface area values in disagreement with the NSA technique in the case of disordered carbon i.e., lower than NSA in case of high oxygen content (more than 2%), but higher for low oxygen content (less than 1%). Because carbon blacks are solids which exhibit graphitic structure, some milled graphite samples, were taken as model materials and analyzed. Surface area was determined by using both NSA and N≩I2 techniques, and the difference between the results given by the two techniques were observed and related to the microstructure, which was analyzed by using X-ray diffraction, Raman spectroscopy, and the oxygen content was measured by using elementary analysis. Two different models of iodine adsorption have been proposed, respectively, for the graphitic parts of the graphite grains and for the disordered part of the grains. An analytical relationship between the differences of iodine and nitrogen surface area values, microstructure and oxygen content was pr...