Rosa Taurino

Facile preparation of superhydrophobic coatings by sol–gel processes

Different organic/inorganic compositions and deposition methods were used to prepare superhydrophobic surfaces using metal alkoxides and the sol-gel process. Both surface roughness and composition had to be adjusted in order to obtain very high contact angles and low contact angle hysteresis as a necessary requirement for superhydrophobicity. Multilayer samples with a fluorinated organic-inorganic top layer showed water contact angles of about 157 degrees with low hysteresis (2 degrees ). Water drops rolled easily off their surface at a tilt angle as low as 4 degrees .

Management of agricultural biomass wastes: preliminary study on characterization and valorisation in clay matrix bricks.

In this work the feasibility of using woody agricultural biomass wastes as grapes and cherries seeds, sawdust, as pore forming agent, and sugar cane ash, as silica precursor, in bricks, were reported. Sawdust and grapes and cherries seeds, thanks to their organic substances content, during their combustion, bring an energetic support in the bricks firing phase and act as pore forming agent. Usually the addition of this kind of waste is limited to 10wt.% in order to reach an equilibrium between positive (weight and shrinkage decrease and porosity increase) and negative (increase of water absorption and mechanical resistance decrease) effects. The results show that grapes and cherries seeds, added in a percentage of 5wt.% to a brick formulation, have better influence with respect to the sawdust, maintaining the mechanical properties of the fired brick (950°C), showing modulus of rupture around 21-23MPa with a weight reduction of 3-10% (respect to the standard one). Regarding the sugar cane ash, the addition of 5wt.% improves the mechanical properties (modulus of rupture around 27MPa) and no weight decrease is observed. These results confirmed the role played by this kind of agricultural waste, which thanks to its high silica content (61wt.%) is capable to demonstrate a filler and plasticity reducing effect on the brick bodies. Tests carried out highlighted that the addition of these by-products (5wt.%) do not change negatively the main technological properties measured (water absorption, linear shrinkage, flexural resistance, etc.) and permit to hypothesize their use to obtain bricks with both insulating and higher mechanical properties using a pore agent forming or silica carrier alternative raw materials, respectively.

Facile characterization of polymer fractions from waste electrical and electronic equipment (WEEE) for mechanical recycling

In view of the environmental problem involved in the management of WEEE, and then in the recycling of post-consumer plastic of WEEE there is a pressing need for rapid measurement technologies for simple identification of the various commercial plastic materials and of the several contaminants, to improve the recycling of such wastes. This research is focused on the characterization and recycling of two types of plastics, namely plastic from personal computer (grey plastic) and plastic from television (black plastic). Various analytical techniques were used to monitor the compositions of WEEE. Initially, the chemical structure of each plastic material was identified by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). Polymeric contaminants of these plastics, in particular brominated flame retardants (BFRs) were detected in grey plastics only using different techniques. These techniques are useful for a rapid, correct and economics identification of a large volumes of WEEE plastics.

Functionalization of ceramic tile surface by sol-gel technique.

The aim of this investigation was the surface functionalization of industrial ceramic tiles by sol-gel technique to improve at the same time the cleanability of unglazed surfaces. This objective was pursued through the design and preparation of nanostructured coating that was deposited on polished unglazed tiles by air-brushing. In particular TiO(2)-SiO(2) binary film with 1, 2 or 5wt% of titania were prepared by using tetraethoxysilane and titania nanoparticles as precursors. The obtained films were characterized by scratch tests to verify the adhesion of the coatings to the polished tiles. To mainly evaluate the effect of the thermal treatment (temperature range 100-600 degrees C) on the photocatalicity of the coatings, the films were studied under UV exposure by contact angle measurements and cleanability test. Particular attention has been paid to preserve the aesthetical aspect of the final product and the obtained hue variation was evaluated by means of UV-visible spectroscopy and colorimetric analysis.

Anaerobic digestion of selected Italian agricultural and industrial residues (grape seeds and leather dust): combined methane production and digestate characterization

A combined experimental evaluation of methane production (obtained by anaerobic digestion) and detailed digestate characterization (with physical-chemical, thermo-gravimetric and mineralogical approaches) was conducted on two organic substrates, which are specific to Italy (at regional and national levels). One of the substrates was grape seeds, which have an agricultural origin, whereas the other substrate was vegetable-tanned leather dust, which has an industrial origin. Under the assumed experimental conditions of the performed lab-scale test series, the grape seed substrate exhibited a resulting net methane production of 175.0 NmL g volatile solids (VS)−1; hence, it can be considered as a potential energy source via anaerobic digestion. Conversely, the net methane production obtained from the anaerobic digestion of the vegetable-tanned leather dust substrate was limited to 16.1 NmL gVS−1. A detailed characterization of the obtained digestates showed that there were both nitrogen-containing compounds and complex organic compounds present in the digestate that was obtained from the mixture of leather dust and inoculum. As a general perspective of this experimental study, the application of diversified characterization analyzes could facilitate (1) a better understanding of the main properties of the obtained digestates to evaluate their potential valorization, and (2) a combination of the digestate characteristics with the corresponding methane productions to comprehensively evaluate the bioconversion process.

An efficient and fast analytical procedure for the bromine determination in waste electrical and electronic equipment plastics

In this study, X-ray fluorescence (XRF) spectroscopy was used, in combination with micro-Raman spectroscopy, for a fast determination of bromine concentration and then of brominated flame retardants (BFRs) compounds in waste electrical and electronic equipments. Different samples from different recycling industries were characterized to evaluate the sorting performances of treatment companies. This investigation must be considered of prime research interest since the impact of BFRs on the environment and their potential risk on human health is an actual concern. Indeed, the new European Restriction of Hazardous Substances Directive (RoHS 2011/65/EU) demands that plastics with BFRs concentration above 0.1%, being potential health hazards, are identified and eliminated from the recycling process. Our results show the capability and the potential of Raman spectroscopy, together with XRF analysis, as effective tools for the rapid detection of BFRs in plastic materials. In particular, the use of these two techniques in combination can be considered as a promising method suitable for quality control applications in the recycling industry. GRAPHICAL ABSTRACT

Comparison of biomethane production and digestate characterization for selected agricultural substrates in Italy

Starting from (but not limited to) their importance in the Italian context, three agricultural substrates, two of fruit origin (grape seeds and plum stones) and one of herbaceous origin (woad), were comparatively tested for both biomethane production and digestate characterization. The anaerobic digestion tests showed that grape seeds had the highest net methane production of 253.0 NmL g volatile solids (VS)−1, followed by plum stones, whose best resulting net methane production was 174.7 NmL gVS−1, and finally by woad with a net methane production of 153.1 NmL gVS−1. Interestingly, the best methane productions of the fruit substrates were obtained with different substrate to inoculum ratios (on a VS basis), 1:1 for grape seeds but 2:1 for plum stones. On the other hand, a three-month ageing of woad caused a limited reduction of methane production. The estimation of obtained degrees of conversion, carried out on a chemical oxygen demand (COD) basis for the specific tests achieving the respective best methane productions, gave values of 48%, 31%, and 33% for grape seeds, plum stones, and woad, respectively. The estimated degrees of conversion were evaluated along with the respective methane productions and substrate COD/VS ratios. The comparison of Fourier transform infrared (FT-IR) spectra and differential thermal analysis (DTA) profiles, carried out for selected digestates in pairs, revealed some distinctive differences in the relative intensities or presence and absence of particular peaks in the FT-IR spectra and in the relative intensities of the exothermic peaks or horizontal curve shifting of the DTA profiles.

New fired bricks based on municipal solid waste incinerator bottom ash

The main objective of this work was to study the sintering process and technological properties of new fired bricks based on high amount of post-treated municipal solid waste incinerator bottom ash and refractory clay. In addition, the effect of the minor addition of flux (Na2CO3) or reinforce (corundum) was also highlighted. Several methods were used to study the effect of compositions variations on the sintering process, structure and the mechanical characteristics of the test briquettes. Differential thermal analysis (TG/DTA) and dilatometry techniques were applied to study the thermal behaviour while scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and high-temperature X-ray diffraction were used to elucidate the structure and the phase composition. The mechanical characteristics were estimated by micro-indentation, strength and various physical tests (porosity, linear shrinkage and water absorption, etc). The results highlight the possibility to use very high amount of municipal solid waste incinerator bottom ashes in the production of new fired bricks with good performances at all levels. It is also shown that the addition of additives managed the final properties, affecting the crystal phase formation, porosity and greatly the strength of the samples.

Thin-film morphologies of block copolymers with nanoparticles

Diblock copolymers (BCPs) show phase separation on mesoscopic length scales and form ordered morphologies in both bulk and thin films, the latter resulting in nanostructured surfaces. Morphologies in thin films are strongly influenced by film parameters, the ratio of film thickness and bulk domain spacing. Laterally structured polymer surfaces may serve as templates for controlled assembly of nanoparticles (NPs). We investigated the BCP of poly( n -pentyl methacrylate) and poly(methyl methacrylate) which show bulk morphologies of stacked lamellae or hexagonally packed cylinders. Thin films were investigated by atomic force microscopy and grazing-incidence small-angle X-ray scattering. For film thicknesses f well below d bulk , standing cylinder morphologies were observed in appropriate molar ratios, while film thicknesses around and larger than d bulk resulted in cylinders arranged parallel to surface. To alter and/or improve the morphology also in presence of different NPs (e.g., silica, gold), solvent vapour annealing (SVA) was applied. The BCP morphology usually remains unchanged but periodicities change depending on type and amount of incorporated NPs. It was found that silica clusters enlarge lateral distances of cylinders, whereas Au NPs reduce it. The effect of SVA is weak. The quality of morphology is slightly improved by SVA and lateral distances remain constant or are slightly reduced.

Production of Cement Blocks and New Ceramic Materials with High Content of Glass Waste

Virgin raw materials can be partially replaced by glass waste in order to reduce the environmental impact being its recycling a significant problem for municipalities worldwide. In Italy in 2013, approximately 1,600,000 tons of container glass have been collected but it was not possible to recycle all of them in the glass melting process.This work is focused on the valorization of glass waste as raw material in new cement and ceramic products, to convert it from an environmental and economic burden to a profitable, added-value resource in the formulation of new mixes. Several parameters, such as grinding, forming, firing, etc. have been studied.It has been optimized the grinding and the reclaiming step of waste to obtain an alternative raw material for hot and cold consolidation processes. Chemical, physical and mechanical properties of products were carried out. The results show new real possibilities to use high amounts of glass waste as an alternative raw material in products consolidated either by hot or cold techniques, reducing the management problems of the glass waste.