Annarosa Mangone

Palladium/Zirconium Oxide Nanocomposite as a Highly Recyclable Catalyst for C-C Coupling Reactions in Water

Palladium nanoparticles have been electrochemically supported on zirconium oxide nanostructured powders and all the nanomaterials have been characterized by several analytical techniques. The Pd/ZrO2 nanocatalyst is demonstrated to be a very efficient catalyst in Heck, Ullmann, and Suzuki reactions of aryl halides in water. The catalyst efficiency is attributed to the stabilization of Pd nanophases provided by tetra(alkyl)-ammonium hydroxide, which behaves both as base and PTC (phase transfer catalyst) agent.

Synthesis and analytical characterisation of copper-based nanocoatings for bioactive stone artworks treatment

AbstractBiological agents play an important role in the deterioration of cultural heritage causing aesthetic, biogeophysical and biogeochemical damages. Conservation is based on the use of preventive and remedial methods. The former aims at inhibiting biological attack, and the latter aims at eradicating the biological agents responsible for biodeterioration. Here, we propose the preparation and the analytical characterisation of copper-based nanocoating, capable of acting both as a remedy and to prevent microbial proliferation. Core–shell CuNPs are mixed with a silicon-based product, commonly used as a water-repellent/consolidant, to obtain a combined bioactive system to be applied on stone substrates. The resulting coatings exert a marked biological activity over a long period of time due to the continuous and controlled release of copper ions acting as biocides. To the best of our knowledge, this is the first time that a multifunctional material is proposed, combining the antimicrobial properties of nanostructured coatings with those of the formulations applied to the restoration of stone artworks. A complete characterisation based on a multi-technique analytical approach is presented. Online abstract figureRelease properties and morphological features of copper-based nanocoatings.

XPS, ICP and DPASV analysis of medieval pottery — Statistical multivariate treatment of data

Medieval ceramic sherds have been studied by inductively coupled plasma (ICP) emission spectroscopy and X-ray photoelectron spectroscopy (XPS) in order to acquire knowledge about technological achievements in pottery production in Apulia during the Middle Ages. The XPS results allow to characterize the surface glazes, which are transparent owing to the presence of PbO or opaque-white in case of Sn addition. The study of coloured glossy surfaces, after an optimized chemical etching, has also shed light on the pigment nature of the painted decorations, whose red colour is to be attributed to the presence of Pb3O4 and not of Fe oxides. Quantitative determinations were performed by ICP measurements on samples of differently coloured glazes, clayey slips and ceramic bulks. Pb and Cu, present in one green glaze, were also determined by differential pulsed anodic stripping voltammetry (DPASV). The analytical results were treated by different statistical techniques of multivariate analysis.

A multianalytical study of archaeological faience from the Vesuvian area as a valid tool to investigate provenance and technological features

The investigation was aimed at defining the compositional and structural characteristics of a group of monochrome blue faiences recovered in Pompeii to assess provenance on the basis of their technological features. Different complementary analytical techniques were used: Scanning Electron Microscopy (SEM) to investigate the morphological aspects of the samples and in particular of the interfaces, micro-Raman Spectroscopy and XRPD to identify crystalline phases and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) to assess the elemental composition due to its sensitivity to a wide range of elements and the adequate lateral resolution. Statistical data treatment of the elemental concentrations of both the ceramic bodies and the glazes allowed us to classify the objects into compositional groups and to verify the previously established archaeological hypothesis suggesting an Egyptian provenance for faience of Pompeii.

Towards highly stable aqueous dispersions of multi-walled carbon nanotubes: the effect of oxygen plasma functionalization

In order to improve the dispersion of multi-walled carbon nanotubes (MWCNTs) in aqueous media, their surface functionalization was carried out in O2-fed low-pressure plasmas. Differently from what can be found in the literature of this field, homogeneous functionalization was achieved by generating the plasma inside vials containing the nanotube powders properly stirred. Experimental parameters, such as input power, treatment time and pressure, were varied to investigate their influence on the process efficiency. A detailed characterization of the plasma treated nanotubes, dry and in aqueous suspension, was carried out with a multi-diagnostic analytical approach, to evaluate their surface chemical properties, morphology, structural integrity and stability in the colloidal state. The plasma grafting of polar ionizable (e.g. acid) groups has been proved to successfully limit the agglomeration of MWCNTs and to produce nanotubes suspensions that are stable for one month and more in water.

Mobile Raman spectroscopy analysis of ancient enamelled glass masterpieces

Richly decorated enamelled glass objects and fragments of different provenance and epoch have been analysed using mobile and fixed Raman instruments: some fragments of the outstanding Begram treasure (Musee des arts asiatiques – Guimet, Paris) dated to the 1st century AD, mosque lamps and bottles of Syrian/Egyptian provenance dated to the 13th/14th century (collections of Musee du Louvre and of Musee des arts decoratifs, Paris). The techniques are compared using the data obtained from the study of a group of similar objects and fragments discovered in Melfi Castle in the South of Italy in an archaeological context dated to the last quarter of the 13th century. The glass body was difficult to analyse requiring the use of high-energy high-power laser beams and/or sampling that allowed determining the soda-lime type precisely. In contrast, a variety of colouring agents was identified: lapis lazuli and/or cobalt for blue, antimonate pyrochlore solid solution for yellow, with the addition of cobalt/lapis lazuli for green, hematite for red and calcium phosphate/cassiterite/calcium antimonate for white. Where present, gilding was found applied on a rough and matt red enamel base probably in order to guarantee the physical adherence of the gold leaves. The comparison between the above mentioned groups of objects and between them and data existing in the literature about Roman enamelled glass allowed us to follow the evolution of the technology of this class of precious artefacts and to discuss the potential of the mobile Raman analysis.

Characterisation of mineral waters by pattern recognition methods

Eighty-three samples of mineral water from four different wells in the same district were analysed for 23 parameters. Nineteen parameters were chosen for multivariate analysis. Principal components analysis provided a feature reduction to two or three dimensions without substantial loss of information. The data set is well separated into four clusters using hierarchical and non-hierarchical methods; samples from different wells are generally assigned to different clusters.

Methodology of a combined approach: analytical techniques to identify the technology and raw materials used in thin-walled pottery from Herculaneum and Pompeii

This study focuses on defining compositional and structural characteristics, identifying raw materials and production technology, and validating the archaeological hypothesis of a local production of thin-walled pottery (2nd cent. BC–3rd cent. AD) in the Vesuvian area. Samples investigated were analysed using OM, SEM-EDS, XRD and LA-ICPMS supported by a statistical multivariate treatment of the compositional data of the ceramic bodies. The results obtained show how an integrated approach of analytical techniques can provide answers to archaeological questions and also give a valuable insight into the exchange of raw materials and/or finished products between sites. The paper also discloses how a combined analytical methodology represents a positive step in answering the one question which remains unsolved concerning the entire ceramic production in the Vesuvian area: the provenance of the clayey raw materials used. Indeed, the massive pottery production in the Bay of Naples down the ages contrasts with the unavailability of the necessary clayey local resources.

A systematic characterization of fibulae from Italy: from chemical composition to microstructure and corrosion processes

Fibulae from the archaeological site of Egnatia were examined with the aim of identifying types of alloys, the processes employed for their manufacturing, and outlining the corrosion products. The results obtained, by identifying the raw materials and the technological solutions used allowed us to provide convincing answers to most of the archaeological questions and confirmed the integration of Egnatia in a complex commercial network. In addition, investigations focused on the study of corrosion products, with a view to the planning of more suitable restoration and preservation strategies.

An archaeometric approach to gain knowledge on technology and provenance of Apulian red-figured pottery from Taranto

A large sampling of Apulian red-figured pottery fragments (fifth to fourth century BC) coming from Taranto (Italy) was analyzed by a multi-technique approach. The ceramic bodies’ elemental composition has been obtained by inductively coupled plasma mass spectrometry (ICP-MS), the mineralogical composition of pastes by polarized-light optical and electron microscopies (OM and SEM-EDS), and X-ray powder diffraction (PXRD). The results obtained from the statistical treatment of compositional data, combined with those driven from mineralogical composition of pastes, allow to formulate hypotheses about the provenance of the objects and the manufacturing tradition of the workshops, starting to make it possible to understand the relationships among ceramic technology, artistic expression, and workshop practice in the samples analyzed.