12 research outputs found
Preparation of albumin-ferrite superparamagnetic nanoparticles using reverse micelles
Micellar systems are widely applied as reactors to encapsulate inorganic nanoparticles in polymeric materials. However, only low inorganic contents and microscale dimensions are often achieved. The adsorption of albumin protein on ferrite nanoparticles permits to increase the stability of inorganic dispersions in water by inhibiting particle flocculation. Subsequent glutaraldehyde addition induces protein crosslinking and ferrite entrapment. Polymer–ferrite composite nanoparticles were obtained in this way. The magnetic albumin nanoparticles (25 nm mean diameter) obtained contain about 40wt% of ferrite and show superparamagnetic behaviour. The composite powder was successfully functionalized with amodel drug and the biological activity was evaluated
Electrochemical activity of lightweight borohydrides in lithium cells
As substitutes for graphite, the negative electrode material commonly used in Li-ion batteries, hydrides have the potential to overcome both safety and performance limits of the current state-of-the-art Li-ion cells. Hydrides can operate through a conversion process proved for some interstitial hydrides like MgH 2 : M x A y +nLi= xM+yLi m A, where m=n/y. Even if far from optimization, outstanding performances were observed, drawing the attention on the whole hydride family. Looking for high capacity systems, lightweight complex metal hydrides, as borohydrides, deserve consideration. Capacities in the order of 2000-4000 mAh/g can be theoretically expected thanks to the very low formula unit weight. Although the potential technological impact of these materials can lead to major breakthroughs in Li-ion batteries, this new research field requires to tackle fundamental issues that are completely unexplored. Our preliminary findings on the incorporation of borohydrides will be here presented
Hydrogen production by water splitting on manganese ferrite-sodium carbonate mixture. Feasibility tests in a packed bed solar reactor-receiver
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
Phase Separation and Microstructure in Superconducting FeSe1-xTex Materials
In the effort to unveil the relations between synthesis conditions, morpho-structural features and superconducting properties of (11)-type iron-based superconductors, this study is focused on FeSe0.5Te0.5 materials obtained from high-temperature melts and different cooling rates. Crystalline and chemical composition are evaluated by means of XRD and SEM analyses, highlighting the formation of complex multiphase structures: the obtained results suggest that high-temperature nucleating phases may play a key role in the observed phase separation. Superconducting properties, evaluated by magnetization measurement and dc electrical resistance in different magnetic field conditions up to 18 T, highlight the low homogeneity of the superconducting phases, reflecting the microstructural observation