New thiophene monolayer-protected copper nanoparticles: synthesis and chemical-physical characterization

For the first time copper 3-(6-mercaptohexyl)thiophene-protected nanoparticles (Cu T6SH) have been synthesized by a one-phase system, utilizing anNaBH4/LiCl mixture in diglyme as the reducing reagent and avoiding water medium dissolving copper salts. The prepared nanoclusters, characterized by transmission electron microscopy (TEM), have shown a constant spherical morphology with a size dimension of 5-6 nm in diameter. After their synthesis, no morphological evolution and irreversible aggregation process has been observed after a storage inCH2Cl2at low temperature for a period up to six months long. Cu T6SH nanoparticles have been investigated by UV-Visible (UV-Vis) and Fourier transmission infrared (FTIR) spectroscopes to characterize the alkylthiophenes monolayer conformations and the particles optoelectronic properties. The UV-Vis reveals the lack of the surface plasmonic band, previously observed in Cu-nanosized clusters at about 556–570 nm, and shows a wide-band centered at 293 nm, probably due to the high-conformational surface ordering of thiophene rings on the Cu core. The results highlight the importance of the modifications ported to the well-known one-phase synthetic reactions to obtain a clear lack, even after a storage of six months, of any irreversible aggregation that has always characterized chain thiophene-protected metallic nanoparticles

Concentratore solare

Forma oggetto della presente invenzione un concentratore solare per illuminare una sospensione algale che comprende: - almeno un elemento ottico (1) atto a ricevere la radiazione solare; -almeno una fibra ottica (3), avente una faccia di ingresso (11) e una faccia di uscita (12); -almeno un filtro ottico spettralmente selettivo (9), interposto lungo il percorso tra detta radiazione solare e detta faccia di ingresso (11) di detta almeno una fibra ottica (3); caratterizzato dal fatto che detto filtro ottico (9) trasmette solo la porzione spettrale massimamente attiva ai fini fotosintetici, iflettendo e/o assorbendo la porzione spettrale scarsamente utile ai fini fotosintetici

SOLAR CONCENTRATOR

The present invention relates to a solar concentrator for illuminating an algal suspension, which comprises: - at least one optical element (1) suitable for receiving solar radiation; - at least one optical fiber (3), having an input face (11) and an output face (12); - at least one spectrally selective optical filter (9), situated along the path between said solar radiation and said input face (11) of said at least one optical fiber (3); characterized in that said optical filter (9) transmits only the spectral portion which is most active for photosynthesis purposes, reflecting and/or absorbing the spectral portion which is of little use for photosynthesis purposes

Comparison between inorganic geomimetic chrysotile and multiwalled carbon nanotubes in the preparation of one-dimensional conducting polymer nanocomposites

The aim of this study was to examine the role of the nanofillers spatial arrangement in the electrical properties of hybrid organic-inorganic fibers. In this paper, we have presented experimental results for preparation of fibers with a nanometric diameter based on a polyaniline/poly(ethylene oxide) doped blend and geomimetic chrysotile nanotubes. The nanostructured material was prepared using electrospinning techniques. Electrospun fibers made by pristine polymers and by the same blend loaded with carbon nanotubes were used as reference materials to compare the structural, and electrical properties of the novel organic-inorganic material. Generally, electrical properties were improved by the addition of materials that have high conductivity. Electrospun fibers filled with a traditional insulator like chrysotile have shown higher electrical conductivity than the pristine materials. In order to fully understand how structural variations impact upon the electrical conductivity the materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), differential scanning calorimetry (DSC) and four-point probe method. The results suggest that the occurred electrical conductivity gain could be attributed to parallel orientation of the chrysotile nanotubes and higher crystallinity induced by the one-dimensional nanostructured filler materials. The obtained results bring us one step closer to using intrinsically conducting polymers (ICPs) in the creation of functionalized polymeric nanocomposites for nanotechnology

Adsorption of bovine serum albumin onto synthetic Fe-doped geomimetic chrysotile

Synthetic stoichiometric and Fe-doped geomimetic chrysotile nanocrystals represent a reference standard to investigate the health hazard associated with mineral asbestos fibres. Experimental evidence suggests that the generation of reactive oxygen species and other radicals, catalysed by iron ions at the fibre surface, plays an important role in asbestos-induced cytotoxicity and genotoxicity. In this study, structural modification of bovine serum albumin (BSA) adsorbed onto synthetic chrysotile doped with different amounts of Fe has been investigated by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and analytical pyrolysis coupled with gas chromatography-mass spectrometry. FT-IR data evidenced a marked increase in disordered structures like random coil and \u3b2-turn of BSA-nanocrystal adduct with 0.52 wt% of Fe doped. The TGA profile of the BSA revealed that its interaction with the synthetic chrysotile surface was strongly affected by the substitution of Fe into the chrysotile structure. The 2,5-diketopiperazine yields, formed upon thermal degradation of the polypeptide chain ( pyrolysis-gas chromatography), changed when the BSA was adsorbed on the nanofibres. In general, results suggested that minute amount (less than 1 wt%) of Fe doping in chrysotile affected the protein-nanofibre interactions, supporting the role that this element may play in asbestos toxicity. The catalytic role of iron and the consequent unfolding of protein due to the structural surface modification of nanofibres were also evaluated

TUBO DIFFUSORE

Forma oggetto della presente un tubo diffusore di luce, caratterizzato dal fatto che detto tubo di luce è rivestito da un film OLF e permette la fuoriuscita di luce ad intensità pressoché costante per l’intera lunghezza di detto tubo. Forma ulteriore oggetto della presente invenzione un metodo per la crescita di alghe che comprende: a) Inoculo e crescita fototrofica delle alghe in un primo reattore; b) Trasferimento delle alghe ottenute nel passaggio a) in un secondo reattore e crescita delle stesse in un processo mixo trofico; c) Raccolta delle alghe. Forma ulteriore aspetto della presente invenzione un impianto che massimizza la resa e la qualità del prodotto ottenuto secondo il metodo dell’invenzione

Spectroscopic characterization of Fe-doped synthetic chrysotile by EPR, DRS and magnetic susceptibility measurements

Fe-doped synthetic geomimetic chrysotile nanocrystals represent a reference standard to investigate the health hazard associated with asbestos fibers and constitute interesting inorganic nanotubes for specific technological applications in light harvesting systems, optoelectronics and photonics. As the fiber toxicity is catalyzed by iron ions in specific crystallographic sites and the mechanical behaviour of synthetic chrysotile nanotubes is strongly affected by the iron doping extent, the characterization of Fe substitution to Mg and/or Si sites in the chrysotile structure appears highly important. By EPR, DRS spectroscopic analyses and magnetic investigations, Mg and/or Si ion replacement by Fe3+ in a synthetic geomimetic chrysotile structure has been investigated. The results highlight that, as a function of the Fe doping extent and of the Fe doping process, iron can replace both Mg and Si sites. The contemporary iron substitution into the octahedral and tetrahedral sheets is associated with the presence of both of isolated Fe3+ centres in high-spin 3d5 configuration (S = 5/2, 6A1( 6S)) in Oh and Td symmetry and of intra-lattice clustered species. Increasing the Fe doping extent increases the concentration of aggregated species, while magnetic susceptibility confirms a paramagnetic anisotropy. The results allow to define the opportunity of using or not metallic Fe during the synthesis to obtain doped chrysotile nanocrystals with tailored morphological and structural properties suitable as a reference to study asbestos toxicity and apt to prepare new inorganic nanotubes and quantum wires for innovative technological applications

TiO2 nanopowders for sensing applications; a comparison between traditional and hydrothermal synthesis way

Aim of the work is to compare the morphological properties of TiO2 powders obtained by different methods. The microstructure of powders is a fundamental parameter to judge if the material is suitable for gas sensing. Materials for chemical sensors have to be composed by nanometric and spherical shaped grains sintered in controlled conditions aimed to obtain Schottky barriers. We investigated a traditional sol-gel (SG) and an hydrothermal (HY) approach to obtain titanium dioxide powders. The same starting materials were chosen for both SG and HY method, a Ti-organometallic precursor and, as solvent, an hydroalcoholic solution. The work is focused on the different methodology and on the outcome related to the two methods (we describe step by step both of them). HY TiO2 powder shows smaller grains than SG TiO2 maintaining spherical shape. A comparison among different handled HY powders shows the role of dwelling time (at fixed temperature) on the nanostructure of grains. Experimental observations are mainly based on XRD and SEM analyses

Preface

3 pagesInternational audienc

Biomineralization: from fundamentals to biomaterials & environmental issues.

350 pagesInternational audienc