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Per- and polyfluoroalkyl substances (PFAS) are considered emerging contaminants and have been increased their attention due to their distribution in water body. These compounds are acid and characterized by a thermal stability to make them resistant to degradation processes. Activities such as tannery, paper and cardboard production, waterproof cloths, produce wastewater rich in PFAS and heavy metals. There are currently no Maximum Contaminant Levels established for PFAS chemicals and the Environmental Protection Agency is working on the definition of a technical guidance providing information on health effects and methods for the treatment of drinking water. The adsorption process is one of the technologies used for the treatment of wastewater and food residues are getting increased attention as bio-adsorbent because they can be found easily as wastes or by-products and at almost no cost. In this work the removal of PFAS was performed by using food waste such as Yerba Mate (YM) as bio-adsorbent. Adsorption tests were performed at different pH condition (from 3 to 10) and temperature (from 10 °C to 40 °C). The concentration of pollutants was determined by HPLC, UV-VIS and TOC analysis. SEM-EDS, XRD, FT-IR and BET were done to achieve a characterization of the adsorbent material.

The use of fiber reinforced polymers (FRPs) as a replacement of traditional homogeneous materials is still hindered by their brittle behavior and poor interlaminar resistance. Interleaving veils in polymer matrix, especially with fibers at the nanoscale dimension, is considered as one of the most promising toughening methods. By considering the hierarchical nature of the resulting laminated composites, their properties are intrinsically dependent on the interaction between the nanofibrous veils and the thermosetting resin and, in an attempt to tailor the interfacial adhesion between the electrospun fibers and matrix, surface modification of the fibers with the integration of inorganic nanostructures could be a solution. This work is an investigation on the use of commercially available electrospun nylon nanofibers decorated with ZnO nanorods obtained by three-step chemical synthesis. The modified veils were interleaved in carbon/epoxy prepreg composites and their mechanical properties were evaluated under Low Velocity Impact (LVI) tests at different energy levels (5 J and 7.5 J). Although the presence of ZnO nanorods did not limit the extension of the delaminated area in case of high energy level test (7.5 J), nanomaterials contributed positively to reduce the extent of the damaged area when a low energy impact was adopted (5 J). A beneficial effect of ZnO-functionalized commercial electrospun veils was observed in the flexural strength of laminated composites. After LVI tests at 5 J and 7.5 J, the flexural strength resulted higher compared to that observed in the same tests on specimens with non-decorated veils (NY4M), thus suggesting a positive role played by ZnO nanorods in hindering delamination propagation.

The present research is focused on the synthesis of hexagonal ZnO wurtzite nanorods for the decoration of commercially available electrospun nylon nanofibers. The growth of ZnO was performed by a hydrothermal technique and for the first time on commercial electrospun veils. The growth step was optimized by adopting a procedure with the refresh of growing solution each hour of treatment (Method 1) and with the maintenance of a specific growth solution volume for the entire duration of the treatment (Method 2). The overall treatment time and volume of solution were also optimized by analyzing the morphology of ZnO nanostructures, the coverage degree, the thermal and mechanical stability of the obtained decorated electrospun nanofibers. In the optimal synthesis conditions (Method 2), hexagonal ZnO nanorods with a diameter and length of 53.5 nm ± 5.7 nm and 375.4 nm ± 37.8 nm, respectively, were obtained with a homogeneous and complete coverage of the veils. This easily scalable procedure did not damage the veils that could be potentially used as toughening elements in composites to prevent delamination onset and propagation. The presence of photoreactive species makes these materials ideal also as environmentally friendly photocatalysts for wastewater treatment. In this regard, photocatalytic tests were performed using methylene blue (MB) as model compound. Under UV light irradiation, the degradation of MB followed a first kinetic order data fitting and after 3 h of treatment a MB degradation of 91.0% ± 5.1% was achieved. The reusability of decorated veils was evaluated and a decrease in photocatalysis efficiency was detected after the third cycle of use.

Different surface treatments including mercerization, stearic acid and growth of zinc oxide nanorods as well as their combinations were exploited to address their effects on the properties of green composites based on polylactic acid (PLA) and flax fabrics. The resulting fabrics were morphologically (SEM), crystallographically (XRD) and thermally (TGA) characterized, showing no significant changes with respect to the untreated samples. In contrast, tensile and flexural properties of composites produced by compression moulding were significantly influenced. A combination of mercerization and environmentally friendly stearic acid treatment turned the character of the flax fabric from hydrophilic to hydrophobic, and led to improved bending and tensile strengths by 20% and 12%, respectively, compared to untreated composites. The presence of ZnO nanorods promoted an increase in flexural and tensile stiffness by 58% and 31%, respectively, but at the expense of strength, with reductions ascribed to the degradation of polylactic acid under high-temperature conditions favoured by ZnO, as confirmed by a reduction in the initial thermal degradation temperature up to 26%. These latter composites can be suggested in those applications where a suitable combination of flexural properties and a shorter persistence in the environment is desired.

The composites based on basalt fibres and poly(lactic acid) (PLA) show promising applications in biomedical and automotive fields, but their mechanical performance is still largely hindered by poor interfacial properties. Zinc oxide nanorods have been successfully used to tune the PLA/basalt fibre interface by growing them on commercially available basalt fabrics. The hierarchical fibres significantly enhanced the mechanical properties of PLA-based composites, especially their flexural strength and stiffness. These values are 26% and 22% higher than those of unmodified basalt/PLA composites, and 24% and 34% higher than those of glass/PLA composites used as a baseline. The increase in tensile and flexural properties hinges on the mechanical interlocking action promoted by ZnO nanorods and on the creation of a compact transcrystallinity structure. A degradation of PLA matrix was detected but it was positively counteracted by the better interfacial stress transfer. This study offers a novel approach for modifying the fibre–matrix interface of biocomposites intended for high-performance applications.

The urgent need to make natural fibre composites suitable for semi-structural applications demands a thorough assessment of their behaviour under different loading conditions and strain rates. In this regard, low velocity impact represents a severe hazard to the composite industry due to the resulting complex damage scenario able to markedly impair the mechanical properties of composite structures. The aim of this chapter is to provide a comprehensive review of the resistance to low velocity impacts of natural fibre composites, with a view to highlighting the effects of the various factors that influence the impact resistance of traditional fibre reinforced composites. The potential of natural fibre composites and differences with the behaviour of the synthetic counterparts are addressed, along with the areas that need improvement for a better exploitation of natural fibre composites in semi- or structural applications. Literature survey highlighted that also for natural fibre composites the toughness of the matrix dictates the energy absorbed at perforation, the damage resistance and tolerance, which are largely independent of fibre architecture. Another important feature, for energies far from perforation, is the less detrimental role played by delamination compared to synthetic laminates.

The outstanding specific mechanical properties of carbon fiber reinforced laminates are often counteracted by the poor interlaminar fracture toughness that makes them prone to global failure induced by delamination onset and propagation. The availability of nanofillers have triggered the development of composites reinforced from the micro down to the nanoscale, the so called hierarchical composites. These composites mimic biological materials and promise high mechanical performance with added functionalities. This chapter reviews the recent advances in the exploitation of the multiscale approach to increase interlaminar toughness of advanced carbon fiber reinforced laminates. The techniques for nano-reinforcement integration in conventional composites, from in-situ growth and/or deposition on fibers, dispersion in the matrix, and interleaving of self-standing assemblies are discussed, with a view to emphasizing opportunities, limits and challenges with regard to Mode I and II interlaminar fracture toughness and low velocity impact loading.

The effects of electrospun veil position, areal density and concurrent presence of MWCNTs on the low velocity impact behaviour and damage tolerance of thin cross-ply carbon/epoxy laminates were investigated. Three different interleaved configurations were tested along with baseline laminates and the optimal configuration was then used to assess the effect of veil density (1.5 gsm and 4.5 gsm) and CNT doping on the damage tolerance. The presence of nanofibrous interlayers resulted in a decrease higher than 40% in the delaminated area for impacts up to 7.5 J without weight penalty and degradation of the in-plane flexural properties. SEM micrographs of fractured surfaces allowed to identify the synergistic contribution of MWCNTs and nanofibres to the effective toughening of traditional laminates. Energy absorption mechanisms were found similar to those described in fracture toughness studies, which resulted in a better damage tolerance of modified laminates in terms of residual flexural strength and stiffness.

The presence of a secondary phase between the fibres and the matrix has proved to be a good approach for interphase tailoring for enhanced load transfer. In this regard, an optimization of the low-...

The weathering and deterioration of historical buildings, as well as that of many monuments or sculptures using natural stones, is a problem that has been known since antiquity. In this work, we have obtained an innovative waterborne coating made of silica-armored polymer particles. The synthetic approach aimed at maximizing the presence of the silica at the particle surface and its attachment to the polymer is discussed. The performance of the coating is evaluated in two natural building stones that have widely different porosities, Carrara marble and Lecce stone. It was found that the coatings maintained the aesthetics upon ageing, reduced liquid water absorption by capillary and let the water vapor permeate. Moreover, the addition of the nanosilica improves the mechanical resistance, making them suitable to use as protective coatings in total agreement with the regulations in the field of protective natural stones.

International audience; The ideal mechanical performance of a composite is controlled by the level of interfacial adhesion and to overcome the incompatibility issues between plant fibres and polymeric matrices, the surface of flax yarns has been modified by zinc oxide (ZnO) nanostructures. The ZnO nanorods were synthesized through a lowtemperature hydrothermal treatment, and several parameters have been analysed in order to obtain a uniform and homogeneous ZnO interphase, such as the number of the seeding cycles, the growth reaction times and the replacement of the growth solution. The results showed that it is possible to obtain highly oriented and well aligned ZnO nanostructures (by FE-SEM), with an hexagonal wurtzite structure (by XRD) and a high degree of coverage along the whole yarn (by TGA), reducing the number of the seed cycles, with rather long growth times (5 hours) and substituting the growth solution at least once during the synthesis. The experimental conditions preserved the breaking force of the yarns, while Single Fibre Fragmentation Tests (SFFT) highlighted a better interfacial adhesion of ZnO-modified flax yarns with epoxy matrix, which displayed a 29 % reduction in average debonding length relative to untreated yarns.

Four different strategies for mitigating the highly hydrophilic nature of flax fibers were investigated with a view to increase their compatibility with apolar polypropylene. The effects of two carbon nanostructures (graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs)), of a chemical modification with a fatty acid (stearic acid), and of maleated polypropylene on interfacial adhesion, mechanical properties (tensile and flexural), and thermal stability (TGA) were compared. The best performance was achieved by a synergistic combination of GNPs and maleated polypropylene, which resulted in an increase in tensile strength and modulus of 42.46% and 54.96%, respectively, compared to baseline composites. Stearation proved to be an effective strategy for increasing the compatibility with apolar matrices when performed in an ethanol solution with a 0.4 M concentration. The results demonstrate that an adequate selection of surface modification strategies leads to considerable enhancements in targeted properties.

The use of wood fibers is a deeply investigated topic in current scientific research and one of their most common applications is as filler for thermoplastic polymers. The resulting material is a biocomposite, known as a Wood Polymer Composite (WPC). For increasing the sustainability and reducing the cost, it is convenient to increase the wood fiber content as much as possible, so that the polymeric fraction within the composite is thereby reduced. On the other hand, this is often thwarted by a sharp decrease in toughness and processability&mdash, a disadvantage that could be overcome by compounding the material with a toughening agent. This work deals with the mechanical properties in tension and impact of polypropylene filled with 50 wt.% wood flour, toughened with different amounts (0%, 10%, and 20%) of a polypropylene-based thermoplastic vulcanizate (TPV). Such properties are also investigated as a function of extrusion processing variables, such as the feeding mode (i.e., starve vs. flood feeding) and screw speed. It is found that the mechanical properties do depend on the processing conditions: the best properties are obtained either in starve feeding conditions, or in flood feeding conditions, but at a low screw speed. The toughening effect of TPV is significant when its content reaches 20 wt.%. For this percentage, the processing conditions are less relevant in governing the final properties of the composites in terms of the stiffness and strength.

Basalt fibers were functionalized by ZnO electroless deposition for obtaining a nanostructured interphase for enhancing the interfacial strength with an epoxy resin matrix. The structural, morphological and wetting properties of the pristine basalt fabrics and ZnO-coated basalt fabrics were evaluated. The fabrics were uniformly coated with ZnO nanostructures featuring a wurtzite structure and a twin hexagonal prism morphology. The contact angle measurements revealed that ZnO prisms transformed the hydrophilic basalt fabric into a hydrophobic one (~130°). ZnOs were also grown on the basalt fibers as yarns to evaluate their interfacial adhesion by single fiber pull-out tests. The results emphasize significant improvement in the apparent interfacial shear strength (~42%) with limited degradation of the pristine basalt fiber tensile strength (a reduction of ~ 17%). Therefore, ZnO electroless deposition can be regarded as an effective route to improve the mechanical performance of basalt/epoxy composites expanding their potential range of applications as structural materials.

International audience; Thermoplastic fiber metal laminates (TFMLs) represent a relatively new class of fiber metal laminates (FMLs) specifically designed to overcome the limitations of conventional fiber metal laminates in terms of the elevated processing temperatures and pressures required for their consolidation. In this work the low velocity impact response of TFMLs based on aluminum alloy and a polypropylene (PP) matrix reinforced with basalt fibers has been experimentally addressed, by considering the effect of the stacking sequence and of the impact temperature. The results have been compared with those obtained on glass fiber/PP reinforced FMLs, basalt/epoxy reinforced FMLs and monolithic aluminum. Basalt TFMLs showed a better performance than aluminum plates, basalt/epoxy TFMLs and glass TFMLs, especially for the specific energy level causing FC (first crack), with an increase of 42%, 34%, 8.5% respectively due to a greater deformation ability of basalt fiber metal laminates even at an impact temperature as low as −40 °C.

In this paper, different self-made membranes based on polyethersulfone (PES) with sulfonated nano-Fe3O4 (Fe3O4-SO3H) were tested in H-Type Microbial Fuel Cell system. The nanomaterials were characterized by FTIR, SEM, TEM and TGA, while the nanocomposite membranes by tensile tests, TGA, SEM, and profilometry. The presence of sulfonic groups (-SO3H) within the polymer matrix allowed a better dispersion of nanoparticles and prevented oxygen permeation from the cathodic compartment. Different amounts of filler, ranging from 5 wt% to 20 wt%, were adopted to establish an optimal content for enhancing the electrochemical performances as Power density (PD), Current intensity (CI) and Open Circuit Voltage (OCV), without altering the mechanical and thermal stability of the synthesized materials. PES with 10 wt% of sulfonated Fe3O4 resulted the best formulation among those analyzed with properties superior to commercial Nafion 117 membrane, with an OCV and a Coulombic efficiency equal to 868.09 mV and 29.58%, respectively. The maximum power and current densities improved by 270% and 117% compared to Nafion 117, respectively.

The effects of the integration of continuous sheets of randomly oriented multi-walled carbon nanotubes on the low velocity impact behavior of cross-ply carbon/epoxy laminates have been investigated. Three different energy levels were used, namely 5 J, 10 J, and 20 J and significant reductions in delaminated area in the range 11%–39% compared to the baseline laminates were achieved by incorporating interleaves at each 0/90 interface. This resulted in a better flexural damage tolerance of modified laminates. The combination of ultrasonic C-scans, profilometry, and scanning electron microscopy showed that interlaminar crossing between CNT sheets and carbon fibers occurred in modified laminates and that nanotube pull-out, bridging and improved fiber/matrix adhesion are the mechanisms responsible for the enhanced impact performance.

Les objets conserves en un lieu representent une source precieuse pour tracer d’autres histoires, en replacant dans une perspective interne et familiale des evenements, des circonstances et des personnes, ignores par l’histoire officielle. Certains moments de l’histoire du monastere clarisse de Fara in Sabina (Rieti) sont ici relus a partir d’objets devotionnels (tableaux, statues, bibelots, restes et reliques) qui y sont conserves et dont certains lui furent donnes par le cardinal Francesco Barberini. L’analyse de certaines de ces pieces permet de reconstruire les fragments d’une histoire inedite et d’envisager des hypotheses concernant les politiques religieuses et les orientations cultuelles du monastere. Constituees non seulement par les objets en question, mais aussi par les paroles des religieuses, leurs recits, leurs souvenirs et toutes les ecritures quotidiennes (annotations eparses, notes, chroniques et journaux communautaires, lettres) se rapportant a ces objets, les sources, privees et informelles, eclairent notamment le rapport qui liait Francesco Barberini et Francesca Farnese (1597-1651), fondatrice du lieu, ainsi que les intentions strategiques de Barberini.

Ascertain the distribution of materials and that of their degradation products in historical artifacts is crucial to understand their conservation status. Among the different analytical techniques that can be used, FT-IR imaging supplies information on the molecular composition of the material on a micrometric-scale in a nondestructive way (i.e. respecting the physical integrity of the material/object and without inducing visible damage to the object. This is possible by limiting the sampling to very small amounts.) (K.H.A. Janssens, R. van Grieken, Non-destructive microanalysis of cultural heritage materials, Elsevier, 2004). When thin sections of the material are not exploitable for transmission, and when ATR imaging mode is not suitable due to possible damages on the sample surface, FT-IR imaging is performed in reflection mode on thick polished, matrix embedded samples. Even if many efforts have been done in the optimization of the sample preparation, the material's surface quality is a critical issue that can hinder the achievement of good infrared images. Moreover, spectral artifacts due to volume and surface interactions can yield uncertain results in standard data treatment. In this paper we address a multivariate statistical analysis as an alternative and complementary approach to obtain high contrast FT-IR large images from hyperspectral data obtained by reflection μ-FTIR analysis. While applications of Principal Component Analysis (PCA) for chemical mapping is well established, no clustering unsupervised method applied to μ-FTIR data have been reported so far in the field of analytical chemistry for cultural heritage. In order to obtain certain chemical distribution of the stratigraphy materials, in this work the use of Hierarchical Cluster Analysis (HCA), validated with a supervised Principal Component based k-Nearest Neighbor (PCA-kNN) Analysis, has been successfully used for the re-construction of the μ-FTIR image, extracting useful information from the complex data set. A case study (a patina from the Arch of Septimius Severus in the Roman Forum) is presented to validate the model and to show new perspectives for FT-IR imaging in art conservation.

Physico-mechanical properties and the microstructure of basalt fiber reinforced hydraulic lime-based mortars were investigated. Three different mortars were characterized, one based on natural hydraulic lime and a siliceous aggregate and two dry premix of natural hydraulic lime, selected inert aggregates and selected crushed bricks and tiles. The effect of three different types of basalt fibers at two contents on mechanical and water absorption through capillarity was investigated. Fiber reinforced mortars showed a marked improve in post-cracking behavior and compressive strength which was found to depend strongly on the type of matrix and basalt fiber. Reinforced mortars exhibited a lower capillary water absorption coefficient than the reference mortars regardless of type of matrix and basalt fiber. Despite the promising results, the study highlighted the need to optimize both the surface treatment of basalt fibers and their content in the mortars with a view to defining a suitable material for masonry restoration.

L'articolo indaga la produzione e la patrimonializzazione dell’oggetto considerato “sacro” in ambito cattolico europeo. In particolare, si analizza il processo, compiuto da religiose di clausura specializzate, attraverso il quale il resto umano è trasformato in oggetto reliquia, con riferimento alle dinamiche di conservazione e di diffusione in ambito claustrale e, più in generale, ecclesiastico.

This paper is based on an extensive and engaged ethnographic study in which the researcher lived the life of a postulant in two French Carmelite monasteries. The aim is to discuss the relation between sound (auditory sensation) – here intended as silence, i. e. the absence of sound or noise – and monastic space, highlighting to what extent the construction of space is implemented on a basis which is mostly sound-related and how such a soundscape, in turn, can produce and preserve certain shared behaviours and life values. Thus, the focus is not so much on silence and its generally accepted devotional function as a medium for prayer; rather, the emphasis is placed on its social value as a performative, group-building and identity de/construction tool. O artigo baseia-se num estudo etnográfico extensivo no âmbito do qual a autora experimentou a vida de noviça em dois carmelos franceses. Pretende-se discutir a relação entre som (sensação auditiva) – aqui compreendido como silêncio, ou seja, como ausência de som ou rumor – e o espaço conventual, destacando até que ponto a construção do espaço é realizada, em grande medida, a partir do som, e como essa paisagem sonora pode, por sua vez, produzir e sustentar determinados comportamentos e valores partilhados. Assim, mais do que a função devocional do silêncio como meio para a oração, generalizadamente aceite, a ênfase é colocada no seu valor social como ferramenta performativa, de (des)construção identitária e de formação grupal.

Per mettere a punto leganti qualificati per il ripristino di edifici storici sono state studiate le proprietà meccaniche e la microstruttura di malte modificate con fibre corte di basalto con differente morfologia e concentrazione. Ecco i risultati della sperimentazione.

Sur la base d’une recherche ethnographique de terrain menee en France et en Italie, cette contribution interroge le concept de secret inherent aux pratiques de production et de re-production de l’objet-relique dans la cloture chretienne contemporaine. Elle s’interesse aux traitements materiels et symboliques operes principalement par des Carmelites sur les restes d’un saint ou d’un bienheureux. Plus encore, elle s’attache au role du secret dans le controle d’un processus et a l’apparition de competences hierarchisees, inscrites dans un systeme de communication reserve a une minorite. Il s’agit d’observer comment ces religieuses, s’etant soustraites a l’influence du clerge seculier, ont su – par le biais de pratiques dissimulees – s’amenager des niches de competence et d’autonomie.

Francesca Sbardella a effectué une recherche de terrain dans des couvents carmélites en Bretagne et en Italie. Elle s’est particulièrement intéressée à la fabrication des reliques de la duchesse Françoise d’Amboise, béatifiée en 1863 et considérée comme la fondatrice des carmélites en France. Ce qui est très intéressant, note Francesca Sbardella, c’est que les religieuses françaises et italiennes spécialisées dans la fabrication de ces objets auxquels est reconnue une valeur extrahumaine présentent leur pratique comme érudite. L’auteur interroge donc cette pratique élitaire, secrète, transmise par voie initiatique et à la fois sous-tendue et conditionnée par la représentation même de la bienheureuse Françoise d’Amboise, construite au travers de la lecture et de la connaissance parfaite des textes hagiographiques la concernant. Numéro thématique A. Herrou et A. Poujeau (dir.), Savoirs monastiques. Érudition et ascèse

The application of coating polymers to building materials is a simple and cheap way to preserve and protect surfaces from weathering phenomena. Due to its environmentally friendly character, waterborne coating is the most popular type of coating, and improving its performance is an important key of research. The study presents the results regarding the mechanical and photo-oxidation resistance of some water-based acrylic coatings containing SiO2 nanoparticles obtained by batch miniemulsion polymerization. Coating materials have been characterized in terms of hydrophobic/hydrophilic behavior, mechanical resistance and surface morphology by means of water-contact angle, and scrub resistance and atomic force microscopy (AFM) measurements depending on silica-nanoparticle content. Moreover, accelerated weathering tests were performed to estimate the photo-oxidation resistance of the coatings. The chemical and color changes were assessed by Fourier-transform infrared spectroscopy (FTIR) and colorimetric measurements. Furthermore, the nanofilled coatings were applied on two different calcareous lithotypes (Lecce stone and Carrara Marble). Its properties, such as capillary water absorption and color modification, before and after accelerated aging tests, were assessed. The properties acquired by the addition of silica nanoparticles in the acrylic matrix can ensure good protection against weathering of stone-based materials.

À partir d’une expérience ethnographique menée dans deux couvents français de carmélites, on a cherché à analyser les modalités concrètes de la vie claustrale. Sont examinés ici un cas limite d’utilisation de la parole, déclinée dans la spécificité de parole-silence, et la construction de familiarité qui se forme autour d’elle. On souhaite proposer une lecture phénoménologique du silence claustral, sur le plan de l’agi, de l’entendu et du parlé. Tout doit se réduire à l’essentiel, c’est-à-dire à l’élimination du superflu, qu’il s’agisse du matériel, del’émotionnel ou du linguistique. Listening, looking and staying quiet: dialogue in an enclosed community This is an analysis of the reality of enclosed life on the basis of an ethnographic study in two French Carmelite nunneries. The paper examines an extreme case of language use: the language of silence and the construction of familiarity which it creates. We propose a phenomenological reading of enclosed silence as it relates to actions, hearing and speaking. The ultimate aim is to reduce everything to the essential by eliminating the superfluous whether it be material, emotional orlinguistic.