Sub-Micrometric MCM-41 Particles as Support to Design Efficient and Regenerable Maghemite-Based Sorbent for H₂S Removal.

In this work, highly dispersed maghemite (λ-Fe₂O₃) in form of ultrasmall nanoparticles (about 2 nm) was embedded into a mesostructured silica MCM-41 (about 600 nm) featuring regular submicrometric hexagonal shaped particles via the two-solvent incipient wetness impregnation strategy. The obtained nanocomposite was then tested as H₂S sorbent in the mid-temperature range. When compared with a commercial sorbent (Katalko 32-5), it showed superior performances after the first sulfidation which remained steady over three repeated sulfidation cycles, highlighting the regenerability properties of the composite.

Oleate-Based Solvothermal Approach for Size Control of MFe₂O₄ (M ═ Mn, Fe) Colloidal Nanoparticles.

The versatility of a promising and repeatable oleate-based solvothermal approach has been explored through the synthesis of MnFe₂O₄ and -Fe₂O₃/Fe₃O₄ nanoparticles in form of colloidal dispersions and the tuning of the particle and crystallite sizes. Spinel ferrite nanoparticles with controlled-size in the range 7-14 nm with dispersity below 15% was reached for both MnFe₂O₄ and λ-Fe₂O₃/Fe₃O₄. The size-tuning was obtained with three different pathways: (i) direct approach by changing the solvent polarity or the precursor concentration; (ii) post-synthesis solvothermal treatment in the presence of metal oleates; (iii) post-synthesis solvothermal treatment in the absence of metal oleates.

Spinel Ferrite Core-Shell Nanostructures by a Versatile Solvothermal Seed-Mediated Growth Approach and Study of Their Nanointerfaces.

An easy, low-cost, repeatable seed-mediated growth approach in solvothermal condition has been proposed to synthesize bimagnetic spinel ferrite core-shell heterostructures in the 10-20 nm particle size range. Cobalt ferrite and manganese ferrite nanoparticles (CoFeO and MnFeO) have been coated with isostructural spinel ferrites like maghemite/magnetite, MnFeO, and CoFeO with similar cell parameters to create different heterostructures. The conventional study of the structure, morphology, and composition has been combined with advanced techniques in order to achieve details on the interface at the nanoscale level.

Combination of grape extract-silver nanoparticles and liposomes: A totally green approach.

In the present work, silver nanoparticles were prepared using a totally green procedure combining silver nitrate and an extract of grape pomace as a green source. Additionally, nanoparticles were stabilized using phospholipid and water and/or a mixture of water and propylene glycol (PG). To the best of our knowledge, grape-silver nanoparticle stabilized liposomes or PG-liposomes were formulated, for the first time, combining the residual products of wine-made industry, silver nitrate and phospholipids, avoiding the addition of hazardous substances to human health and the environment, in an easy, scalable and reproducible method.

Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process.

The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp.

Hierarchical Formation Mechanism of CoFe2O4 Mesoporous Assemblies.

The development of synthetic hybrid organic-inorganic approaches and the understanding of the chemico-physical mechanisms leading to hierarchical assembly of nanocrystals into superstructures pave the way to the design and fabrication of multifunction microdevices able to simultaneously control processes at the nanoscale. This work deals with the design of spherical mesoporous magnetic assemblies through a surfactant assisted water-based strategy and the study of the formation mechanism by a combined use of transmission electron microscopy, X-ray diffraction, and time-resolved small angle X-ray scattering techniques. We visualize the hierarchical mechanism formation of the magnetic assemblies in the selected sodium dodecylsulfate (SDS)-assisted water-based strategy.

Core-shell nano-architectures: the incorporation mechanism of hydrophobic nanoparticles into the aqueous core of a microemulsion.

This work presents an in-depth investigation of the molecular interactions in the incorporation mechanism of colloidal hydrophobic-capped nanoparticles into the hydrophilic core of reverse microemulsions. (1)H Nuclear Magnetic Resonance (NMR) was employed to obtain molecular level details of the interaction between the nanoparticles capping amphiphiles and the microemulsion surfactants. The model system of choice involved oleic acid (OAC) and oleylamine (OAM) as capping molecules, while igepal-CO520 was the surfactant.

Surfactant-assisted route to fabricate CoFe2O4 individual nanoparticles and spherical assemblies.

A surfactant-assisted route in aqueous media has been shown to be suitable to prepare either individual primary CoFe(2)O(4) nanocrystals or secondary spherical nanoporous assemblies with a high surface area. The formation of primary nanoparticles or of spherical assemblies is found to be dependent on the presence of the surfactant and on the particle size, but is shown that the nanoparticle-surfactant interface plays a dominant role. The size of the primary CoFe(2)O(4) particles is controlled by the type of salt, the synthesis temperature and the concentration of the precursors.