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NiO-based films and nanostructured materials have received increasing attention for a variety of technological applications. Among the possible strategies for their fabrication, atomic layer deposition (ALD) and chemical vapor deposition (CVD), featuring manifold advantages of technological interest, represent appealing molecule-to-material routes for which a rational precursor design is a critical step. In this context, the present study is focused on the coordination sphere engineering of three heteroleptic Ni(II) β-diketonate–diamine adducts of general formula [NiL2TMEDA] [L = 1,1,1-trifluoro-2,4-pentanedionate (tfa), 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedionate (fod) or 2,2,6,6-tetramethyl-3,5-heptanedionate (thd), and TMEDA = N,N,N′,N′-tetramethylethylenediamine]. Controlled variations in the diketonate structure are pursued to investigate the influence of steric hindrance and fluorination degree on the chemico-physical characteristics of the compounds. A multi-technique investigation supported by density functional calculations highlights that all complexes are air-insensitive and monomeric and that their thermal properties and fragmentation patterns are directly dependent on functional groups in the diketonate ligands. Preliminary thermal CVD experiments demonstrate the precursors' suitability for the obtainment of NiO films endowed with flat and homogeneous surfaces, paving the way to future implementation for CVD end-uses. [ABSTRACT FROM AUTHOR]

Sustainable development compliant with environment and human health protection motivates researchers to explore green solutions towards improved economic and social wellbeing. These objectives, still very far from being achieved especially in developing countries, must necessarily be pursued through the tailored fabrication of low-cost, eco-friendly, efficient and stable multi-functional materials. In particular, nanostructures based on first-row transition metal oxides are amenable candidates for clean energy production, air purification and self-cleaning/anti-fogging purposes, especially if obtained through fabrication strategies allowing a careful modulation of their characteristics. In this highlight, after a brief introduction of the above issues, we provide selected representative examples of green oxide-based nanoarchitectures for the targeted end-uses. Attention is focused on the interplay between the material chemico-physical properties and the resulting functional performances, with the aim of providing some hints to control material behavior by design. In addition, we provide a critical outlook not only on the unique opportunities, but also on the main open challenges related to the use of the above multi-functional materials, in an attempt to stimulate further advancements in these emerging research areas. [ABSTRACT FROM AUTHOR]

Flavonols are one of the most promising class of bioactive compounds belonging to the broad family of the flavonoids, characterized by a unique set of features in their basic chemical skeleton and several specific substitutions in selected position of the rings A, B and C. This interesting class of phytochemicals includes compounds such as quercetin, kaempferol, myricetin, rhamnetin, morin, fisetin, galagin, azaleatin and their respective glycosyl derivatives. They have been identified in several foods and provide them great health benefits. This review updates and integrates, in a critical fashion, the current knowledge on flavonols as food sources, chemical features, structure-activity relationships, bioavailability and health benefits (from preclinical and clinical studies), focusing on both in vitro and in vivo reports. Dietary flavonols are bioavailable molecules in human with impressive health benefits (such as antioxidation, cardioprotection, antibacterial, antiviral and anticancer activity) and the process of metabolization also produces compounds with remarkable bioactivities just like the corresponding precursors. Their inclusion into human diet is highly recommended for their unquestionable health promoting properties, being excellent nutraceuticals as well as ingredients for good functional food. [Display omitted] • Food flavonols are nutraceuticals with remarkable biological applications. • Basic skeleton of flavonols has characteristic features for their functionality. • Some foods in the human diet are very rich source of flavonols. • Flavonols have promising anticancer, antimicrobial, antioxidant and antiviral properties. [ABSTRACT FROM AUTHOR]

Co3O4 thin films and nanosystems are implemented in a broad range of functional systems, including gas sensors, (photo)catalysts, and electrochemical devices for energy applications. In this regard, chemical vapor deposition (CVD) is a promising route for the fabrication of high-quality films in which the precursor choice plays a key role in the process development. In this work, a heteroleptic cobalt complex bearing fluorinated diketonate ligands along with a diamine moiety [Co(tfa)2·TMEDA; tfa = 1,1,1-trifluoro-2,4-pentanedionate and TMEDA = N,N,N′,N′-tetramethylethylenediamine] is investigated as a potential Co molecular precursor for the CVD of Co3O4 systems. For the first time, the compound is characterized by crystal structure determination and comprehensive analytical studies, focusing also on its thermal properties and fragmentation patterns, important figures of merit for a CVD precursor. The outcomes of this investigation, accompanied by detailed theoretical studies, highlight its very favorable properties for CVD applications. In fact, growth experiments under oxygen atmospheres containing water vapor revealed the suitability of Co(tfa)2·TMEDA for the fabrication of high-quality, phase-pure Co3O4 thin films. The versatility of the proposed strategy in tailoring Co3O4 structural/morphological features highlights its potential to obtain multi-functional films with controllable properties for a variety of eventual technological end-uses. [ABSTRACT FROM AUTHOR]

Aerobic organisms have to overcame the dangerous species derived from the unquestionable favorable effects due to the utilization of oxygen in the cellular respiration. 2,3-Diphosphoglycerate (DPG) could be one of the molecules able to perform different role inside the cells and (from the data obtained from our experimental work) may help cellular components, in particular hemoglobin, to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS). Therefore, we have investigated the kinetic and antioxidant properties of this molecule against the main biological reactive species and the protective role of this molecules on hemoglobin treated with strong oxidant. DPG, at the physiological concentration is able to scavenge hydroxyl radical, peroxyl radical, cation radicals and to chelate iron in the reduced state. Moreover it is able to avoid oxidation of iron inside the hemoglobin following treatment with nitrite and tert-butyl hydroperoxide (t-BOOH). On the other side, it is not able to protect membrane components from oxidative burning. This different behavior towards radical species is probably linked to the polarity of the molecule and also the high levels of charged groups present on the surface of DPG, that avoid the possibility to act in an environment almost completely hydrophobic, as inside the membrane, where reactive species produce the main damages during the reactions of peroxidation. This is the first paper dealing with the potential role of DPG not only as a modulator of oxygen affinity in hemoglobin, but also as a scavenger of radicals. Unlabelled Image • Diphosphoglycerate performs a basic antioxidant activity. • Diphosphoglycerate protects hemoglobin against oxidation due to RNS and t-BOOH. • Diphosphoglycerate chelates ferrous ions. • Diphosphoglycerate scavenges hydroxyl radical, peroxyl radical and cation radicals. [ABSTRACT FROM AUTHOR]

Silica-supported silver nanoparticles were obtained by rf sputtering from Ar plasmas under soft synthesis conditions, with particular attention to the combined influence of rf power and total pressure on the system composition, nanostructure, morphology, and optical properties. In order to attain a thorough insight into the nucleation and growth phenomena of Ag nanoparticles on the silica substrate, several in situ and ex situ characterization techniques were used. In particular, a laser reflection interferometry system was employed for a real-time monitoring of the deposition process, providing useful and complementary information with respect to the other ex situ techniques (x-ray photoelectron spectroscopy and x-ray excited Auger electron spectroscopy, glancing incidence x-ray diffraction, atomic force microscopy, optical-absorption spectroscopy, and transmission electron microscopy). The above investigations evidenced the formation of silver-based nanosystems (average crystallite size <=10 nm), whose features (metal content, Ag particle size and shape, structure and optical properties) could be carefully tailored by moderate and controlled variations of the synthesis parameters. [ABSTRACT FROM AUTHOR]

Metal nanoparticles on oxide matrices have gained a markedly increasing consideration with regard to both scientific and applicative purposes, thanks to the possibility of tailoring the system characteristics by a proper choice of the preparation route and the processing conditions. In the present work, Au/SiO2 nanocomposites were prepared by radio-frequency (rf) sputtering of gold from Ar plasmas on amorphous silica substrates. Particular attention was devoted to the influence of the synthesis parameters on the chemicophysical properties of the final nanosystems. To this regard, both in situ and ex situ characterization techniques were adopted. In particular, laser reflection interferometry was employed for an in situ monitoring of growth processes, while ex situ analyses were specifically dedicated to the investigation of Au/SiO2 nanostructure, chemical composition, optical properties, and surface morphology (glancing-incidence x-ray diffraction, transmission electron microscopy, spectroscopic ellipsometry, x-ray photoelectron spectroscopy, ultraviolet-visible absorption, and atomic force microscopy). The obtained results showed the possibility of tailoring the Au/SiO2 morphology from clusterlike to islandlike systems or continuous films, with consequent modification of the optical properties, by a proper choice of total pressure, rf power, deposition time, and growth temperature. [ABSTRACT FROM AUTHOR]

A facile two-step vapor phase synthetic approach is proposed for the fabrication of Mn3O4 thin films chemically modified with fluorine, and eventually functionalized with silver or titania. The adopted strategy exploits the initial chemical vapor deposition (CVD) of Mn3O4 on Si(100) substrates starting from a diamine diketonate Mn(ii) complex, followed by the controlled radio frequency (RF)-sputtering of silver or titania. Complementary analytical techniques were employed to investigate the crystallinity (X-ray diffraction), chemical composition (X-ray photoelectron spectroscopy, secondary ion mass spectrometry, energy dispersive X-ray spectroscopy), morphology and nano-organization (field emission-scanning electron microscopy, atomic force microscopy, transmission electron microscopy) of both pristine and functionalized manganese oxide thin films. Under the adopted operating conditions, the target Mn(ii) complex acted as a single-source precursor for both Mn and F, leading to the formation of phase-pure hausmannite Mn3O4 films characterized by a uniform in-depth fluorine content. In addition, the obtained results gave evidence of the formation of high purity Ag/F:Mn3O4 and TiO2/F:Mn3O4 composites with a close contact between the single constituents. This work outlines an amenable and efficient method for the vapor phase growth of composite Mn3O4-based thin films, which are favorable candidates for diverse technological applications, from photocatalysis to gas sensing. [ABSTRACT FROM AUTHOR]

Indium tin oxide (ITO) substrates were functionalized with fluoroalkylsilanes (FAS) having formula R F C(O)N(R)(CH 2 ) 3 Si(OMe) 3 ( 1 , R = H, R F  = C 5 F 11 ; 2 , R = CH 3 , R F  = C 5 F 11; 3 , R = H, R F  = C 3 F 7 ) and containing embedded amide moieties between the perfluoroalkyl chain and the syloxanic moiety. Subsequently, Au nanoparticle deposition (AuNP) onto the ITO-FAS functionalized surfaces was carried out by immersion into a solution of citrate-stabilized AuNP. The ITO-FAS and AuNP/ITO-FAS modified systems were characterized by various complementary techniques and compared with AuNP/ITO modified with R F (CH 2 ) 2 Si(OEt) 3 ( 4 , R F  = C 6 F 13 ), free from functional groups between the fluorinated tail and the syloxanic moiety. The results showed that only ITO glasses modified with 1 , 2 and 3 displayed an oleophobic, as well as hydrophobic, behaviour and that the AuNP Surface Coverage (SC %) directly depended on the fluoroalkylsilane nature with the following trend: 60% ITO-2  > 16% ITO-3  > 9% ITO-1  > 3% ITO-4 . The obtained results revealed that, in organosilane 2 , the presence of a methyl group on the amide nitrogen increases the steric hindrance in the rotation around the N CO bond, resulting in the co-presence of two stable conformers in comparable amounts. Their co-presence in solution, combined with the lack of intermolecular N H⋯OC N hydrogen bonds among the anchored molecules, has dramatic influences on the functionalized ITO, yielding a disorderedly packed coating able to accommodate a large quantity of AuNP. These results indicate that AuNP can act as excellent probes to evaluate the coating layer quality but, at the same time, it is possible to tune the gold loading on electroactive surfaces depending on the chemical structure of the used fluorinated silane. [ABSTRACT FROM AUTHOR]

Photoreforming promoted by metal oxide nanophotocatalysts is an attractive route for clean and sustainable hydrogen generation. In the present work, we propose for the first time the use of supported Mn3O4 nanosystems, both pure and functionalized with Au nanoparticles (NPs), for hydrogen generation by photoreforming. The target oxide systems, prepared by chemical vapor deposition (CVD) and decorated with gold NPs by radio frequency (RF) sputtering, were subjected to a thorough chemico-physical characterization and utilized for a proof-of-concept H2 generation in aqueous ethanolic solutions under simulated solar illumination. Pure Mn3O4 nanosystems yielded a constant hydrogen production rate of 10 mmol h–1 m–2 even for irradiation times up to 20 h. The introduction of Au NPs yielded a significant enhancement in photocatalytic activity, which decreased as a function of irradiation time. The main phenomena causing the Au-containing photocatalyst deactivation have been investigated by morphological and compositional analysis, providing important insights for the design of Mn3O4-based photocatalysts with improved performances. [ABSTRACT FROM AUTHOR]

High purity porous ZnO nanopyramids with controllable properties are grown on their tips on Si(100) substrates by means of a catalyst-free vapor phase deposition route in a wet oxygen reaction environment. The system degree of preferential [001] orientation, as well as nanopyramid size, geometrical shape, and density distribution, can be finely tuned by varying the growth temperature between 300 and 400 °C, whereas higher temperatures lead to more compact systems with a three-dimensional (3D) morphology. A growth mechanism of the obtained ZnO nanostructures based on a self-catalytic vapor-solid (VS) mode is proposed, in order to explain the evolution of nanostructure morphologies as a function of the adopted process conditions. The results obtained by a thorough chemico-physical characterization enable us to get an improved control over the properties of ZnO nanopyramids grown by this technique. Taken together, they are of noticeable importance not only for fundamental research on ZnO nanomaterials with controlled nano-organization but also to tailor ZnO functionalities in view of various potential applications. [ABSTRACT FROM AUTHOR]

Citrus fruit and juices represent one of the main sources of compounds with a high potential for health promoting properties. Among these compounds, flavanones (such as hesperetin, naringenin, eriodictyol, isosakuranetin, and their respective glycosides), which occur in quantities ranging from ∼180 to 740 mg/L (depending on the Citrus species and cultivar) are responsible for many biological activities. These compounds support and enhance the body's defenses against oxidative stress and help the organism in the prevention of cardiovascular diseases, atherosclerosis, and cancer. Moreover, among other properties, they also show anti-inflammatory, antiviral, and antimicrobial activities. This review analyzes the biochemistry, pharmacology, and biology of Citrus flavanones, emphasizing the occurrence in Citrus fruits and juices and their bioavailability, structure-function correlations and ability to modulate signal cascades both in vitro and in vivo. © 2017 BioFactors, 43(4):495-506, 2017 [ABSTRACT FROM AUTHOR]

Phloretin and phlorizin are the two strong natural antioxidants whose biological and pharmacological applications are rapidly growing in different human pathological conditions. The neuroprotective activity of the two flavonoids has been analyzed on cell culture of neuroblastoma cells. The neuroprotective activity of the two flavonoids has been analyzed on cell culture of neuroblastoma cells and evaluated by testing cell vitality, mitochondrial transmembrane potential and ROS production, antioxidant enzymes detection, activation of caspase 3, DNA damage, protein carbonylation, lipid peroxidation, and superoxide anion scavenging activity. Incubation of cells with rotenone caused cell death and significant increase in intracellular reactive oxygen species, activation of caspase 3, and variation in mitochondrial transmembrane potential. Although, rotenone exposure caused a significant increase of antioxidant enzymes, high levels of lipid peroxidation were also observed. Phloretin or phlorizin, at micromolar concentration, reduced rotenone-induced cell death by scavenging ability against superoxide anion radical, one of the main effectors of rotenone toxicity at level of mitochondrial respiratory chain complex I. Under our experimental conditions, a reduction of the intracellular ROS levels with consequent normalization of the aforementioned antioxidant enzymes occurred. Concomitantly, we observed the inhibition of caspase 3 activity and DNA damage. This study shows the promising neuroprotective ability of the two dihydrochalcones able to protect human differentiated neuroblastoma cells (commonly used as model of Parkinson's disease) from injury induced by rotenone, actively scavenging ROS, normalizing mitochondrial transmembrane potential and consequently avoiding energy depletion. © 2017 BioFactors, 43(4):549-557, 2017 [ABSTRACT FROM AUTHOR]

Tannins are a heterogeneous group of high MW, water-soluble, polyphenolic compounds, naturally present in cereals, leguminous seeds and, predominantly, in many fruits and vegetables, where they provide protection against a wide range of biotic and abiotic stressors. Tannins exert several pharmacological effects, including antioxidant and free radical scavenging activity as well as antimicrobial, anti-cancer, anti-nutritional and cardio-protective properties. They also seem to exert beneficial effects on metabolic disorders and prevent the onset of several oxidative stress-related diseases. Although the bioavailability and pharmacokinetic data for these phytochemicals are still sparse, gut absorption of these compounds seems to be inversely correlated with the degree of polymerization. Further studies are mandatory to better clarify how these molecules and their metabolites are able to cross the intestinal barrier in order to exert their biological properties. This review summarizes the current literature on tannins, focusing on the main, recently proposed mechanisms of action that underlie their pharmacological and disease-prevention properties, as well as their bioavailability, safety and toxicology.Linked Articles: This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc. [ABSTRACT FROM AUTHOR]

Jatropha (Jatropha curcas L.) is a plant native of Central and South America, but widely distributed in the wild or semi-cultivated areas in Africa, India, and South East Asia. Although studies are available in literature on the polyphenolic content and bioactivity of Jatropha curcas L., no information is currently available on plants grown in pedoclimatic and soil conditions different from the autochthon regions. The aim of the present work was to characterize the antioxidant system developed by the plant under a new growing condition and to evaluate the polyphenol amount in a methanolic extract of leaves. Along with these analyses we have also tested the antioxidant and cytoprotective activities on lymphocytes. RP-HPLC-DAD analysis of flavonoids revealed a chromatographic profile dominated by the presence of flavone C-glucosydes. Vitexin is the most abundant identified compound followed by vicenin-2, stellarin-2, rhoifolin, and traces of isovitexin and isorhoifolin. Methanolic extract had high scavenging activity in all antioxidant assays tested and cytoprotective activity on lymphocytes exposed to tertz-buthylhydroperoxide. The results highlighted a well-defined mechanism of adaptation of the plant and a significant content of secondary metabolites with antioxidant properties, which are of interest for their potential uses, especially as a rich source of biologically active products. [ABSTRACT FROM AUTHOR]

Background Interactions of ligands with proteins imply changes in the properties of the macromolecules that may deeply modify their biological activities and conformations and allow them to acquire new and, sometimes, unexpected abilities. The flavonoid phloretin has several pharmacological properties that are starting to be elucidated, one of which is the well-known inhibition of glucose transport. Methods The interactions of phloretin to human serum albumin have been investigated by fluorescence, UV–visible, FTIR spectroscopy, native electrophoresis, protein ligand docking studies, fluorescence and scanning electron microscopy. Results Spectroscopic investigations suggest that the flavonoid binds to human serum albumin inducing a decrease in α-helix structures as shown by deconvolution of FTIR Amide I′ band. Fluorescence and displacement studies highlight modifications of environment around Trp214 with the primary binding site located in the Sudlow's site I. In the hydrophobic cavity of subdomain IIA, molecular modeling studies suggest that phloretin is in non-planar conformation and hydrogen-bonded with Ser202 and Ser454. These changes make HSA able to withstand protein degradation due to HCLO and fibrillation. General significance Our work aims to open new perspectives as far as the binding of flavonoids to HSA are concern and shows as the properties of both compounds can be remarkable modified after the complex formation, resulting, for instance, in a protein structure much more resistant to oxidation and fibrillation. This article is part of a Special Issue entitled “Science for Life” Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. [ABSTRACT FROM AUTHOR]

Every year tons of pistachio hulls are separated and eliminated, as waste products, from pistachio seeds. In this study the hulls of ripe pistachios were extracted with two organic solvents (ethanol and methanol) and characterized for phenolic composition, antioxidant power and cytoprotective activity. RP-HPLC-DAD-FLU separation enabled us to identify 20 derivatives, including and by far the most abundant gallic acid, 4-hydroxybenzoic acid, protocatechuic acid, naringin, eriodictyol-7- O -glucoside, isorhamnetin-7- O -glucoside, quercetin-3- O -rutinoside, isorhamnetin-3- O -glucoside and catechin. Methanol extraction gave the highest yields for all classes of compounds and presented a higher scavenging activity in all the antioxidant assays performed. The same was found for cytoprotective activity on lymphocytes, lipid peroxidation and protein degradation. These findings highlight the strong antioxidant and cytoprotective activity of the extract components, and illustrate how a waste product can be used as a source of nutraceuticals to employ in manufacturing industry. [ABSTRACT FROM AUTHOR]

Sanguinello and Tarocco are the blood orange ( Citrus sinensis (L.) Osbeck) cultivars most diffused worldwide. Reversed phase liquid chromatography coupled with MS-MS analysis showed that these two varieties have a similar chromatographic pattern, characterised by the presence of C - and O -glycosyl flavonoids. Of the two, Sanguinello was found to be far richer in flavonoids than Tarocco. In the juices, twelve individual components were identified for the first time, namely, four C -glycosyl flavones (lucenin-2, vicenin-2, stellarin-2, lucenin-2 4′-methyl ether and scoparin), three flavonol derivatives (quercetin-3- O -(2-rhamnosyl)-rutinoside, quercetin-3- O -hexoside, quercetin 3-hydroxy-3-methylglutaryl-glycoside), an O -triglycosyl flavanone (narirutin 4′- O -glucoside) and a flavone O -glycosides (chrysoeriol 7- O -neoesperidoside). Moreover, the influence of the identified C - and O -glycosyl flavonoids on the antioxidant and acetylcholinesterase activity of these juices has been evaluated. [ABSTRACT FROM AUTHOR]

Metal/organosilane/oxide sandwich structures were prepared via a two-step self-assembly method. First, indium tin oxide (ITO) substrates were functionalized with the following fluoroalkylsilanes (FAS): R F C(O)N(H)(CH 2 ) 3 Si(OMe) 3 ( 1 , R F = C 5 F 11 ), containing an embedded amide between the perfluoroalkyl chain and the syloxanic moiety, and R F (CH 2 ) 2 Si(OEt) 3 ( 2 , R F = C 6 F 13 ). Subsequently, Au nanoparticles (Au NPs ) introduction in the obtained systems was carried out by controlled immersion into a solution of citrate-stabilized Au NPs . The physico-chemical properties of the target materials were thoroughly investigated by using various complementary techniques. Finally, the application of such systems as catalysts for methanol electro-oxidation under alkaline conditions was investigated, revealing the synergistical role played by FAS and Au NPs in promoting a remarkable electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Supported Fe2O3–TiO2 nanocomposites are fabricated by an original vapor phase synthetic strategy, consisting of the initial growth of Fe2O3 nanosystems on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition, followed by atomic layer deposition of TiO2 overlayers with variable thickness, and final thermal treatment in air. A thorough characterization of the target systems is carried out by X-ray diffraction, atomic force microscopy, field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. High purity nanomaterials characterized by the co-presence of Fe2O3 (hematite) and TiO2 (anatase), with an intimate Fe2O3–TiO2 contact, are successfully obtained. In addition, photocatalytic tests demonstrate that, whereas both single-phase oxides do not show appreciable activity, the composite systems are able to degrade methyl orange aqueous solutions under simulated solar light, and even visible light, with an efficiency directly dependent on TiO2 overlayer thickness. This finding opens attractive perspectives for eventual applications in wastewater treatment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Phloretin inhibit growth of some Gram positive and Gram negative bacteria. [•] Glycosylation dramatically decrease antimicrobial activity of phloretin. [•] Phloretin shows a MICs against S. aureus ATCC 6538 and MRSA between 7.81 and 125μgmL−1. [•] Phloretin decrease enzymatic activity of catalase, lactate and isocitrate dehydrogenase. [ABSTRACT FROM AUTHOR]

In this paper we report on the first example of Fe2O3/CuO composites fabricated by a two-step vapor-phase synthetic strategy. The target route is based on the CVD of Fe2O3 nanorod arrays on Si(100) at 400 °C starting from Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N, N, N′, N′-tetramethylethylenediamine), followed by radio frequency (RF) copper sputtering for various process durations, and final ex-situ annealing in air. The combined use of complementary structural, morphological, and chemical analyses give evidence of the formation of pure nanocomposite systems, characterized by the presence of the sole ϵ-Fe2O3 and CuO phases. The unique features of the adopted approach enable an efficient surface decoration of ϵ-Fe2O3 rods by CuO nanoparticles a few nm in diameter, resulting in an intimate contact between the two oxides, and a CuO content tunable through variations of the sole sputtering time. [ABSTRACT FROM AUTHOR]

[Display omitted] • β-Fe 2 O 3 /CuO and β-Fe 2 O 3 /WO 3 nanoheterostructures are developed via a two-step vapor-phase route. • The fabricated materials are tested as De-NO x photocatalysts. • The target heterostructures show an enhanced NO photochemical removal with negligible release of toxic intermediates. • The performances higher than those of single oxides are attributed to O defectivity and enhanced charge carrier separation. • •O 2 − radicals are the main species contributing to NO x oxidation. The increasing release and accumulation of harmful nitrogen oxides (NO x with x = 1,2) in industrial and urban environments renders the efficient removal of these atmospheric pollutants an urgent and obligatory issue. In this regard, the advantages yielded by photocatalytic oxidation processes have triggered the search for eco-friendly catalysts featuring an improved efficiency. In this work, we propose the use of heterostructures based on β-Fe 2 O 3 , a scarcely investigated iron(III) oxide polymorph, as viable De-NO x photocatalysts with appealing functional performances. The present materials were fabricated in supported form by chemical vapor deposition (CVD) of Fe 2 O 3. A proof-of-principle investigation on the modulation of material performances by heterostructure formation is explored through Fe 2 O 3 functionalization with CuO or WO 3 by radio frequency (RF)-sputtering. The obtained results reveal a controllable dispersion of CuO or WO 3 in close contact with β-Fe 2 O 3 , a crucial issue to profitably exploit their mutual interplay for De-NO x applications. A preliminary analysis in this regard evidenced very encouraging conversion efficiency and selectivity towards nitrate formation, outstanding among non-titania oxide-based De-NO x photocatalysts. The improved photoactivity with respect to bare Fe 2 O 3 , CuO and WO 3 was related to a higher oxygen defectivity and an enhanced separation of photogenerated charge carriers, enabled by the matched band edges in the target heterostructures. [ABSTRACT FROM AUTHOR]

Iron(III) oxide nanomaterials are extremely promising for the development of magnetic devices, gas sensors, photocatalysts, and photoelectrodes for solar water splitting. The fabrication of such systems by chemical vapor deposition (CVD) relies on the use of molecular sources joining shelf-stability, high volatility, and clean decomposition. Herein, we report for the first time on a versatile iron(II) precursor, namely Fe(tfa) 2 TMEDA (tfa = 1,1,1-trifluoro-2,4-pentanedionate; TMEDA = N , N , N′ , N′ -tetramethylethylenediamine), combining the above features with a simple molecular concept. A theoretical-experimental characterization confirmed the compound spectroscopic purity and monomeric nature, and enabled to elucidate its structural, vibrational and electronic properties, along with its fragmentation pathway and thermal behavior. The ideal Fe(tfa) 2 TMEDA characteristics for CVD applications were finally validated through the fabrication of high purity iron oxide nanomaterials. The latter, comprising the sole metastable β-Fe 2 O 3 polymorph rather than the most stable rust (α-Fe 2 O 3), were characterized by the occurrence of oxygen defects and a nano-organization tunable as a function of growth temperature and reaction atmosphere. [Display omitted] • An iron(II) diketonate-diamine precursor is proposed for CVD of Fe 2 O 3 nanomaterials. • A theoretical/experimental approach is adopted for Fe(tfa) 2 TMEDA characterization. • A pure adduct with a fully saturated Fe(II) coordination sphere is obtained. • The complex has a high shelf stability, a good volatility and a clean fragmentation. • The compound validation in CVD afforded the scarcely investigated β-Fe 2 O 3 polymorph. [ABSTRACT FROM AUTHOR]

Highlights: [•] Nine flavonoids were identified and quantified by SRM in Moro juice. [•] Five C-glycosyl and a O-glycosides flavones have been identified for the first time. [•] A 3-hydroxy-3-methylglutaryl derivative have been identified for the first time. [•] The identified flavonoids contribute effectively to crude juice antioxidant activity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Eleven flavonoids were identified and quantified by SRM in tangelo juice in a single chromatographic course. [•] Two C-glycosyl flavones and one O-triglycosyl flavanone have been identified for the first time. [•] Antioxidant assays showed that flavonoids contribute significantly to the total antioxidant activity of crude tangelo juice. [•] Analysis of antimicrobial activity showed that tangelo flavonoids are able to inhibit Staphylococcus aureus growth. [ABSTRACT FROM AUTHOR]

Abstract: A single-step plasma enhanced-chemical vapor deposition (PE-CVD) route for the synthesis of F-doped iron(III) oxide nanomaterials is presented. Growth experiments, performed from a fluorinated Fe(II) β-diketonate precursor on Indium Tin Oxide (ITO) between 200 and 400 °C, yielded columnar β-Fe2O3 arrays with a preferential (100) growth direction. The fluorine content in the deposits could be adjusted by the sole variation of the deposition temperature controlling, in turn, the optical absorption and energy bandgap. Photocurrent measurements and Mott–Schottky analyses, carried out in Na2SO4 solution under one sun illumination, evidenced a conductivity switch from n- to p-type upon increasing fluorine amount in the obtained nanomaterials. The sample photocurrent density, donor content and flatband potential support the hypothesis that a progressive substitution of oxygen by fluorine in the iron(III) oxide lattice can alter electronic structure and extend charge carrier lifetimes, making anion-doped β-Fe2O3 an efficient water oxidation catalyst. [Copyright &y& Elsevier]

Abstract: Diosmin is a glycosylated polyphenolic compound, commonly found in fruits and vegetables, which is utilized for the pharmacological formulation of some drugs. The interactions of diosmin to human serum albumin have been investigated by fluorescence, UV–visible, FTIR spectroscopy, native electrophoresis and protein–ligand docking studies. The fluorescence studies indicate that the binding site of the additive involves modifications of environment around Trp214 at the level of subdomain IIA. Combining the curve-fitting results of infrared Amide I′ band, the modifications of protein secondary structure have been estimated, indicating a decrease in α-helix structure following flavonoid binding. Data obtained by fluorescence and UV–visible spectroscopy, FTIR experiments and molecular modeling afforded a clear picture of the association mode of diosmin to HSA, suggesting that the primary binding site of diosmin is located in Sudlow's site I. Computational mapping confirms this observation suggesting that the possible binding site of diosmin is located in the hydrophobic cavity of subdomain IIA, whose microenvironment is able to help and stabilize the binding of the ligand in non-planar conformation. Moreover the binding of diosmin to HSA significantly contributes to protect the protein against degradation due to HCLO and Fenton reaction. [Copyright &y& Elsevier]

Abstract: The development of efficient photocatalytic nanomaterials is of outstanding importance for the conversion of electromagnetic radiation into chemical energy. Among the various technological options, photoreforming of aqueous media containing suitable organic oxygenates is an attractive strategy towards a sustainable H2 generation. In this regard, the present contribution will provide a survey of our recent research activities on photoactivated H2 production over supported oxide-based nanosystems. Their preparation is carried out by original synthetic routes based on chemical vapor deposition (CVD), either thermal or plasma-enhanced (PE-CVD), in some cases combined with radio frequency (RF) sputtering. In particular, we will present and discuss the synthesis, characterization and functional performances of two material classes: (i) single-phase undoped (Cu x O, with x =1, 2; Co3O4) and anion-doped (F:Co3O4) metal oxides; (ii) oxide-based nanocomposites (Ag/ZnO and CuO/ZnO). Beside highlighting the potential of CVD routes in achieving specific nanosystem properties, the future challenges and perspectives for research advancements in these fields will also be outlined. [Copyright &y& Elsevier]

Abstract: Myelin basic protein (MBP) is one of the main protein components of central nervous system that as shown in our work, under appropriate condition, forms spherulites. The structural and morphological features of these elements and the ability of trehalose to decrease or completely avoid their formation have been clarified with different but complementary techniques. The FTIR spectra provided compelling evidence for the presence of a small amount of elements organized in secondary structures such as helices and sheets. Polarized optical microscope observations show the presence of spherulites with an average size ranged from 41 to 61μm, characterized by non-birifrangent core. The fluorescence data supply useful informations that are consistent with the presence of a molecular exclusion effect, following interaction of the disaccharide with protein that involves the environment around the single tryptophan residue. Moreover, study of protein conformational states by SDS-PAGE, let us to state that trehalose completely avoid autocatalytic cleavage properties of MBP up to 4 days of incubation at 37°C and pH 7.4. [Copyright &y& Elsevier]

Ag/ZnO nanocomposites supported on polycrystalline Al2O3 were synthesized by an unprecedented approach combining plasma enhanced chemical vapor deposition (PE-CVD) of ZnO matrices and the subsequent deposition of Ag nanoparticles (NPs) by radio frequency (RF) sputtering. The system structure, composition and morphology were investigated by glancing incidence x-ray diffraction (GIXRD), secondary ion mass spectrometry (SIMS), field emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy (EDXS). A tailored dispersion and distribution of silver particles could be obtained under mild conditions by the sole variation of the sputtering time. Gas sensing properties toward flammable and toxic gases, both reducing (CH3CH2OH, CH3COCH3) and oxidizing (O3), were investigated in the temperature range 100-400°C. Beside the high sensitivity, the developed sensors exhibited a response proportional to Ag content, thanks to catalytic and electronic effects promoted by silver NPs. In addition, discrimination between oxidizing and [ABSTRACT FROM AUTHOR]

Abstract: The preparation of the second generation iron(II) complex Fe(hfa)2·TMEDA (hfa=1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, TMEDA= N,N,N′,N′-tetramethylethylenediamine) is performed by reacting iron(II) chloride with Hhfa and TMEDA in two subsequent steps. Density functional theory data show that the compound possesses a distorted octahedral geometry, with the two β-diketonate ligands in a cis configuration. The complex mass transport properties and fragmentation pattern are investigated by thermal analyses and electron impact mass spectrometry, respectively. In addition, its experimental and simulated IR spectra are presented. For the first time, Fe(hfa)2·TMEDA was successfully applied in the chemical vapor deposition (CVD) of iron oxide on Si(100). Structural, compositional and morphological analyses evidence the possibility of obtaining pure, single-phase and homogeneous β-Fe2O3 films. [Copyright &y& Elsevier]

Abstract: Citrus myrtifolia Raf. (chinotto) flavedo, albedo and carpel membranes from green and ripe fruits, as well as seeds and leaves, were investigated for the first time for their flavonoid and furocoumarin composition. Twenty-three unique compounds distributed in the different fruit/plant parts were identified and quantified. All samples analysed contained flavanone O-glycosides, flavone C- and O-glycosides and furocoumarins; flavedos and albedos also contained significant amounts of polymethoxyflavones. Flavedo and albedo extracts were found to be richest in flavonoids and furocoumarins, containing up to 1.95g/kg fresh weight. Flavedo, albedo and carpel membranes from ripe fruits were found to be richer than the corresponding tissues from unripe fruits. The remarkable radical-scavenging activity of all the extracts was tested by DPPH•, ABTS•+ and FRAP methods, revealing that (i) they were particularly efficient in quenching ABTS•+ radical cations (up to 9.8mM Trolox equivalents), and (ii) flavedo and albedo extracts, on average, showed the highest antioxidant capacity. [Copyright &y& Elsevier]

Abstract: Co3O4-based nanosystems were prepared on polycrystalline Al2O3 by plasma enhanced-chemical vapor deposition (PE-CVD), at temperatures ranging between 200 and 400°C. The use of two different precursors, Co(dpm)2 (dpm=2,2,6,6-tetramethyl-3,5-heptanedionate) and Co(hfa)2·TMEDA (hfa=1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA= N,N,N′,N′-tetramethylethylenediamine) enabled the synthesis of undoped and fluorine-doped Co3O4 specimens, respectively. A thorough characterization of their properties was performed by glancing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM), field emission-scanning electron microscopy (FE-SEM), secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS). For the first time, the gas sensing properties of such PE-CVD nanosystems were investigated in the detection of ethanol and acetone. The results show an appreciable response improvement upon doping and functional performances directly dependent on the fluorine content in the Co3O4 system. [Copyright &y& Elsevier]

p-Type Co3O4 nanostructured films are synthesized by a plasma-assisted process and tested in the photo catalytic production of H2 from water/ethanol solutions under both near-UV and solar irradiation. It is demonstrated that the introduction of fluorine into p-type Co3O4 results in a remarkable performance improvement with respect to the corresponding undoped oxide, high- lighting F-doped Co3O4 films as highly promising systems for hydrogen generation. Notably, the obtained yields were among the best ever reported for similar semiconductor- based photo catalytic processes. [ABSTRACT FROM AUTHOR]

Abstract: Ag/ZnO nanocomposites were developed by a plasma-assisted approach. The adopted strategy exploits the advantages of Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) for the growth of columnar ZnO arrays on Si(100) and Al2O3 substrates, in synergy with the infiltration power of the Radio Frequency (RF)-sputtering technique for the subsequent dispersion of different amounts of Ag nanoparticles (NPs). The resulting composites, both as-prepared and after annealing in air, were thoroughly characterized with particular attention on their morphological organization, structure and composition. For the first time, the above systems have been used as catalysts in the production of hydrogen by photo-reforming of alcoholic solutions, yielding a stable H2 evolution even by the sole use of simulated solar radiation. In addition, Ag/ZnO nanocomposites presented an excellent response in the gas-phase detection of H2, opening attractive perspectives for advanced technological applications. [Copyright &y& Elsevier]

The flavonoid composition of crude Citrus limetta Risso (limetta, Mediterranean sweet lemon) juice was elucidated by means of reverse-phase HPLC–DAD–ESI-MS/MS analysis. In a single course, eight compounds (C- and O-glycosyl flavonoids) were identified, six of which were found for the first time in limetta juice: four C-glucosyl flavones, namely vicenin-2, lucenin-2 4′-methyl ether, orientin 4′-methyl ether and scoparin; the O-glycosyl flavone, rhoifolin; and the O-glycosyl flavanone, eriocitrin. In addition, ABTS·+ and DPPH· radical quenching and FRAP assays demonstrate that limetta juice possesses remarkable antioxidant activity. [ABSTRACT FROM AUTHOR]

Abstract: The flavonoids composition of kumquat (Fortunella japonica) crude juice, obtained from uripe and ripe fruits, were investigated by reverse-phase LC-DAD-ESI-ITMS analysis. Thirteen compounds (C- and O-glycosyl flavonoids) were identified. Acacetin 3,6-di-C-glucoside (1), vicenin-2 (2), lucenin-2 4′-methyl ether (3) narirutin 4′-O-glucoside (4) and apigenin 8-C-neohesperidoside (5) were identified for the first time in kumquat juice. Furthermore, we report on the remarkable antioxidant properties of crude juice, of selected flavonoids fractions and of the main component, phloretin 3′,5′-di-C-glucoside (6). [Copyright &y& Elsevier]

Abstract: Cherimoya is a tropical and subtropical native exotic fruit which has become an important crop due to its tasty flavor, high pulp content, nutritional value and potential use in folk medicine. In this study the pulp of ripe fruits were extracted using three organic solvents (ethanol, methanol and dimethyl formammide) and analyzed for the total phenols, antioxidants power and cytoprotective activity on lymphocyte tert-butyl hydroperoxide treated. Also, potential antiperoxidative activity of each extract has been performed. Organic extracts from cherimoya pulp had powerful antioxidant and ferric reducing power activities and, among the extracts, the dimethyl formammide one showed the highest scavenging activity towards DPPH:glyph name="rad" /> +, O2 − radical and FRAP assay, while the ethanol one showed the highest activity against lipid peroxidation induced by tert-butyl hydroperoxide. Extract protective activities were also evaluated in isolated human peripheral blood lymphocytes exposed to 250μM tert-butyl hydroperoxide. The results showed that all the extracts could significantly enhance cell survival and clearly decrease the release of lactate dehydrogenase, with data almost superimposable for all the tested samples. Moreover RP-HPLC-DAD-ITMS analysis reveals the presence of flavanols and procyanidins (dimers and trimers). These results highlight cherimoya extracts'' strong antioxidant properties, remarkable decrease of lipid peroxidation and cytoprotective effects against strong oxidant, supporting their suitable employment as bioactive elements in cosmetic, pharmaceutical and food processing industries. [Copyright &y& Elsevier]

Co3O4thin films were grown on MgO(100) and MgAl2O4(100) by plasma enhanced-chemical vapor deposition (PE-CVD) from the [Co(dpm)2] precursor. Depositions on both single crystal substrates were performed from Ar/O2plasmas at temperatures between 100 and 400 °C in order to tailor the chemical and physical properties of the synthesized films. The composition, morphology and structure of the Co3O4systems were thoroughly analyzed by XPS, SIMS, FE-SEM and bidimensional XRD. The obtained results evidenced the formation of high-purity and strongly oriented Co3O4thin films, with features dependent on the used substrate and the adopted growth temperature. [ABSTRACT FROM AUTHOR]

Abstract: The qualitative and quantitative flavonoid and furocoumarin composition of crude sour orange (Citrus aurantium L.) juice was determined via reverse-phase LC–DAD–ESI–MS–MS analysis. In a single course, a comprehensive chromatographic profile of 14 compounds (furocoumarins, C- and O-glycosyl flavonoids) was obtained. Seven flavonoids and a furocoumarin were identified for the first time in sour orange juice: three C-glucosides (lucenin-2, vicenin-2 and lucenin-2, 4′-methyl ether), two O-glycosides (rhoifolin 4′-glucoside and narirutin 4′-glucoside), two 3-hydroxy-3-methylglutaryl flavanone glycosides (melitidin and brutieridin) and a furocoumarin (epoxybergamottin). Furthermore, the antioxidant activity of sour orange juice was assessed by means of ABTS + and DPPH radical scavenging assays. [ABSTRACT FROM AUTHOR]

Abstract: Supported ZnO nanorods with a different degree of preferential orientation and tunable morphological features were grown on Si(100) by plasma enhanced-chemical vapor deposition. The combined investigation of the synthesized arrays by RHEED and FE-SEM enabled a thorough insight into their structural properties and growth mechanism, whose control is a key issue in view of potential technological applications. [ABSTRACT FROM AUTHOR]

Abstract: In this work, 1D ZnO nano-assemblies were prepared on Al2O3 substrates by plasma enhanced-chemical vapor deposition (PE-CVD), and characterized in their morphology and chemical composition by field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDXS) and X-ray photoelectron spectroscopy (XPS). For the first time, the sensing performances of PE-CVD ZnO nanosystems were tested in the detection of toxic/combustible gases (CO, H2 and CH4), revealing very good responses already at moderate working temperatures. In particular, carbon monoxide and hydrogen detection was possible already at 100°C, whereas methane sensing required a minimum temperature of 200°C. The performances of the present ZnO nanosystems, that make them attractive candidates for technological applications, are presented and discussed in terms of their unique and controllable morphological organization. [ABSTRACT FROM AUTHOR]

Abstract: During our experimental work, aggregation of bovine serum albumin was obtained incubating the protein solution at 60°C to investigate temperature-induced secondary structure, conformation changes and anti-aggregative activity of trehalose. IR-measurements suggested that in the presence of 1.0M of trehalose there is a little increase in short segment connecting α-helical and a clearly decrease in the loss of α-helix structure and in the formation of intermolecular and antiparellel β-sheet up to 78 and 55%, respectively. Useful information also arose following the temperature evolution of Amide I′ band profile in the range of temperature between 25 and 90°C in absence or in presence of 1.0M trehalose. Complementary information is obtained by electrophoresis, circular dichroism, fluorescence spectroscopy, titration of SH groups and light scattering measurements. Results encouraged biotechnology and pharmaceutical application of the disaccharide and provided evidence for its utilization in degenerative diseases evolving via aggregation process. [Copyright &y& Elsevier]

The antioxidative activity of some natural flavonoids was analyzed against the stable free radical 2,2-diphenyl-1-picryhydrazyl. The results indicate that the scavenging power of the tested flavonols is higher than that of the synthetic antioxidants butylated hydroxyanisole and butylated hydroxytoluene; instead, the flavanones show little activity, as indicated by efficient concentration (EC50) values. Flavonoid autoxidation and interaction with Fe2+ and hydrogen peroxide were tested using erythrocyte membranes as a model. The results show that some compounds, like hesperetin, evidence a pro-oxidant activity higher than the ascorbic acid/iron reference system. The compounds with strong oxidative capability do not only influence cellular redox balance but also activate caspase-3, producing lactate dehydrogenase release and enhancing anionic exchange at the level of band 3 protein. [ABSTRACT FROM AUTHOR]

Abstract: The present work is devoted to the investigation of photoinduced superhydrophilicity (PSH) and photocatalytic oxidation (PCO) activity of quasi-2D zinc oxide nanoplatelets obtained by Chemical Vapor Deposition (CVD). In the case of PCO, the degradation of a fatty compound layer (methyl stearate) was chosen as a test reaction. The peculiar textural and morphological features of such systems resulted in a PSH behavior and in a PCO activity appreciably higher than those of a reference commercial Pilkington® ActivTM Glass. Relevant results are presented and discussed as a function of the structure and morphology of these systems, whose control enables a direct tailoring of the functional response. [Copyright &y& Elsevier]

An adduct of Co(II) 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate with N,N,N′,N′-tetramethylethylenediamine is synthesized by a simple procedure and, for the first time, thoroughly characterized by several analytical methods in order to elucidate its structure (single-crystal X-ray diffraction), chemical composition (elemental analyses, FT-IR), optical properties (UV−vis absorption spectroscopy), thermal behavior (thermogravimetric analysis and differential scanning calorimetry), and fragmentation pathways (electrospray ionization mass spectrometry and tandem mass spectrometry). The target complex is monomeric with a pseudo-octahedral Co(II) core and presents a clean decomposition pathway and a high volatility at moderate temperatures. Preliminary chemical vapor deposition (CVD) experiments highlight its very promising features as a CVD/atomic layer deposition molecular source for cobalt oxide nanosystems. A convenient route for the obtainment of Co(hfa)2·TMEDA is proposed. For the first time, the target product is characterized by single-crystal X-ray diffraction, FT-IR, optical absorption, thermal analyses, and mass spectrometry. The compound possesses a monomeric structure, very favorable mass transport properties, and a clean decomposition pattern, allowing assessment of its suitability as a chemical vapor deposition (CVD)/atomic layer deposition precursor for cobalt oxide nanosystems. The final validation by CVD deposition points out to the attractive properties of Co(hfa)2·TMEDA for such applications. [ABSTRACT FROM AUTHOR]

Abstract: Thermodynamic, circular dichroism (CD), and activity measurements have been used to characterize the different conformational states and the effects of NaCl concentrations (0.0–3.0M) on thermal unfolding of ornithine carbamoyltransferase (OCT) from Alopias vulpinus. Furthermore conformational changes in whole enzyme structure have been monitored by titration of SH-groups. OCT unfolding process follows an irreversible two-state mechanism with a first-order kinetic of denaturation, without breaking-point. NaCl shows very little stabilization effects at low concentration and its action become very important over 1.5M concentration. The presence of 3.0M NaCl completely avoids OCT unfolding at 60, 64 and 66°C. Kinetic and thermodynamic parameters are strongly influenced by the presence of high NaCl concentration. Our experiments showed that NaCl stabilization process involved changes in preferential binding, in electrostatic and van der Waals interactions and exposure of buried site and SH-groups. During thermal denaturation, UV–vis and CD spectroscopy show that high salts concentration preserves OCT activity, avoiding exposure of hydrophobic site and destruction of secondary and tertiary structure elements. [Copyright &y& Elsevier]

Abstract: The availability of soft synthetic processes for the preparation of SiO2 films with tailored features plays a key role for several technological applications, from optics to electronics, from surface modifications to barrier coatings. In such context, this work presents the development and optimization of a Plasma Enhanced-Chemical Vapor Deposition route towards high-purity SiO2 films at near room temperature. Depositions were performed from Ar and Ar–O2 plasmas using tetramethoxysilane as precursor, devoting particular attention to the interplay between film properties and process parameters (RF- (Radio Frequency-) power, total pressure, O2/(Ar+O2) ratio and precursor vaporization temperature). Real-time information on the growth process was gained by Laser Reflection Interferometry, while the chemical composition and bonding structure of the obtained layers were analyzed by Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy. Scanning Electron and Atomic Force Microscopies were adopted to analyze the surface and cross-sectional film morphology. The system structural and optical properties were investigated by means of Glancing Incidence X-Ray Diffraction and UV–Vis spectroscopy. Finally, nanoindentation measurements were performed to investigate film hardness. Under optimized conditions, very pure silica films, characterized by a remarkable optical transparency and favorable mechanical properties, were obtained even at RF-power values as low as 5 W and in the absence of O2 in the plasma. [Copyright &y& Elsevier]

Abstract: Nanocomposite materials based on metal nanoparticles (NPs, guest) in/on oxide matrices (host) have attracted increasing attention thanks to their intriguing chemico-physical properties that can be tailored as a function of NP size, shape and mutual interactions. The possibility to obtain a controlled dispersion of metal particles in/on suitable oxides (inside- and outside-cluster systems, respectively) paves the way to a broad spectrum of technological applications, ranging from heterogeneous catalysis, to gas sensing and non-linear optics. The control of functional performances relies on tailoring the system properties by design through a suitable choice of the synthesis and processing routes. In this context, the present review provides a synoptic overview on our recent research activity concerning nanocomposites containing 11th group metal clusters (Cu, Ag and Au), dispersed in/on oxide matrices (SiO2, TiO2, Al2O3). We begin by briefly outlining the interest and size-dependent properties of such systems. Subsequently, the attention is switched to a survey on the preparation strategies previously adopted in the literature, focusing in particular on the use of soft methods, such as sol–gel (SG), RF-sputtering and their innovative combination. The most relevant results on M′/M x O y nanocomposites (where M′=Cu, Ag, Au and M=Si, Ti, Al) obtained by these routes are then comparatively discussed, highlighting analogies and differences between them. Finally, the most attractive research perspectives in the field are briefly presented. [Copyright &y& Elsevier]