The production and maintenance of road pavements consume resources and produce wastes that are disposed of in landfills. To make more sustainable this activity, we have envisioned a method based on a circular use of residues (oil and char) from municipal solid waste pyrolysis as useful additives for producing improved asphalts and for recycling old asphalts to generate new ones, reducing at the same time the consumption of resources for the production of new road pavements and the disposal of wastes to landfills. This work aims to show the feasibility of the integration of two processes (thermal treatment of municipal solid waste on one side, and that of road pavement production on the other side) where the products deriving from waste pyrolysis become added-value materials to improve the quality of road pavements. In this contribution, we presented the effect of pyrolysis product addition on asphalt binder (bitumen) preparation and aging. Solid and liquid products, deriving from the pyrolysis of two kinds of wastes (refused derived fuel (RDF) and granulated rubber tyre waste), have been used for the preparation of asphalt binder samples. Rheological tests have been performed to determine the mechanical properties of neat asphalt binder (bitumen) and those enriched with pyrolysis derived products. Measurements to evaluate possible anti-aging effects have been also performed. The collected results indicate that char addition strengthens the overall bitumen intermolecular structure while bio-oil addition exerts a rejuvenating activity.

La questione energetica è centrale per il presente ed il futuro dell'essere umano e delle sue attività, e per affrontarla in modo efficace è necessario sviluppare un modo di pensare out-of-the-box. Per trovare nuove soluzioni e nuove strategie, è fondamentale una base culturale ampia che abbracci vari settori (tecnico-scientifico, civile, ambientale) e discipline (chimica, fisica, scienza dei materiali, ingegneria). Data la complessità e la trasversalità delle tematiche incorporate nell'ampio contenitore della questione energetica, una possibile opzione per rendere le persone consapevoli delle proprie conoscenze a riguardo è l'uso di un approccio di tipo ludico. L'attività "Si fa presto a dire 'Energia'!", gioco a quiz presentato dall'Istituto di Scienze e Tecnologie per l'Energia e la Mobilità Sostenibili (STEMS) del CNR al Festival della Scienza di Genova, Edizione 2022 (Linguaggi), è stata quindi sviluppata con l'intento di incuriosire ed avvicinare i partecipanti alle problematiche legate alla questione energetica attraverso il gioco, senza trascurare però la possibilità di fornire accenni sugli aspetti pratici riguardanti i processi di produzione, distribuzione, gestione ed utilizzazione dell'energia nelle sue diverse forme (fonti tradizionali, alternative e rinnovabili). Il gioco, che è stato principalmente proposto a studenti di scuole secondarie, ha visto contrapposte due squadre che, seguendo un percorso stabilito, sono state chiamate a sfidarsi, tra bonus e imprevisti, su domande a risposta multipla appartenenti a tre categorie (definizioni, fonti energetiche, attualità) e prove pratiche. Oltre agli aspetti ludici, l'attività ha cercato di far consolidare le conoscenze e la consapevolezza riguardo l'impatto ambientale dei sistemi energetici, l'uso razionale dell'energia e le tecnologie sostenibili e far sviluppare, attraverso l'uso corretto del linguaggio, una visione ampia e soprattutto critica su queste tematiche.

Modifying bitumens to improve their characteristics is one of the ways to increase road pavement durability reducing maintenance costs and environmental issues. In this study the structural and mechanical characteristics of a 50/70 bitumen modified by two different char samples are presented. The choice of char as bitumen modifier fulfils the recent needs for environmental protection. The two char samples come from the pyrolysis of Refuse Derived Fuel (RDF) and waste tyres (WT), respectively. They differ in composition and morphology and their production took place with different yields. Char-modified bitumens revealed increased shear modulus and resistance to mechanical stress as found by rheometry. Artificial aging of these char-modified bitumens unveiled that the bitumen modified by char from WT (WT-char) possessed a certain resilience against aging, with a reduced increase in rigidity upon aging. The anti-aging effect showed by WT-char was attributed to its higher carbon content, which confers higher compatibility with the bitumen chemical nature and presumably a more uniform dispersion within the bituminous structure thanks to the establishment of more effective interactions.

Sulfated alginates (ASs), as well as several artificially sulfated polysaccharides, show interesting bioactivities. The key factors for structure-activity relationships studies are the degree of sulfation and the distribution of the sulfate groups along the polysaccharide backbone (sulfation pattern). The former param-eter can often be controlled through stoichiometry, while the latter requires the development of suitable chemical or enzymatic, regioselective methods and is still missing for ASs. In this work, a study on the regioselective installation of several different protecting groups on a D-mannuronic acid enriched (M-rich) alginate is reported in order to develop a semi-synthetic access to regioselectively sulfated AS derivatives. A detailed structural characterization of the obtained ASs revealed that the regiose-lective sulfation could be achieved complementarily at the O-2 or O-3 positions of M units through multi-step sequences relying upon a silylating or benzoylating reagent for the regioselective protection of M-rich alginic acid, followed by sulfation and deprotection.

The design and fabrication of platforms reproducing the microenvironment in which the cells can properly acquire a specific fate is a decisive step towards the effective exploitation of stem cell-based nanomedicine. Indeed, the environments and the surfaces wherein the cells can attach, migrate and grow significantly affect stem cell differentiation to specific cell types. In this work, a new-concept bio-interface composed by hybrid eumelanin/ graphene-like/titanium dioxide (EU/GL/TiO2) nanostructures has been prepared by an in situ solvothermal method with the aim to address those specific properties to sustain survival and growth of stem cells as well as to stimulate their differentiation. Information on the chemical and structural properties of both the organic and inorganic components constituting the hybrid nanomaterial was achieved by different analytical techniques (XRD, FTIR, EPR, TGA, SEM, AFM) while the ability of EU/GL/TiO2 interface to support stem cell adhesion, growth and proliferation was probed by in vitro tests with mouse embryonic stem cells (mESCs). In the end, specific in vitro tests demonstrated that the prepared platform efficiently supports the differentiation of mESCs into beating cardiomyocytes and neuronal cells. The tests demonstrated that EU/GL/TiO2 holds those biophysicochemical characteristics to prospectively act as a bio-interface. Furthermore, its chemical composition represents a perspective starting point to subsequently explore the decoration with inductive cues that can be released upon external stimuli to drive the growth and differentiation of neurons and beating cardiomyocytes.

The role of graphene related material (GRM) functionalization on the structural and adsorption properties of MOF-based hybrids was deepened by exploring the use of three GRMs obtained from the chemical demolition of a nanostructured carbon black. Oxidized graphene-like (GL-ox), hydrazine reduced graphene-like (GL), and amine-grafted graphene-like (GL-NH2) materials have been used for the preparation of Cu-HKUST-1 based hybrids. After a full structural characterization, the hybrid materials underwent many adsorption-desorption cycles to evaluate their capacities to capture CO2 and store CH4 at high pressure. All the MOF-based samples showed very high specific surface area (SSA) values and total pore volumes, but different pore size distributions attributed to the instauration of interactions between the MOF precursors and the specific functional groups on the GRM surface during MOF growth. All the samples showed a good affinity toward both gases (CO2 and CH4) and a comparable structural stability and integrity (possible aging was excluded). The trend of the maximum storage capacity values of the four MOF samples toward CO2 and CH4 was HKUST-1/GL-NH2 > HKUST-1 > HKUST-1/GL-ox > HKUST-1/GL. Overall, the measured CO2 and CH4 uptakes were in line with or higher than those already reported in the open literature for Cu-HKUST-1 based hybrids evaluated in similar conditions.

A new class of graphene-related materials (GRMs) obtained as water suspensions through a two-step oxidation/reduction of a nanostructured carbon black, namely graphene-like (GL) materials, has recently emerged. GL materials undergo self-assembly in thin amorphous films after drying upon drop-casting deposition on different surfaces. The GL films, with thicknesses of less than a micron, were composed of clusters of nanoparticles each around 40 nm in size. The exploitation of the GL films for different options (e.g., bioelectronic, sensoristic, functional filler in composite) requires a deep characterization of the material in terms of their electric transport properties and their possible interaction with the surface on which they are deposited. In this work, a careful electrical characterization of GL films was performed at room temperature and the results were compared with those achieved on films of benchmark graphenic materials, namely graphene oxide (GO) materials, obtained by the exfoliation of graphite oxide, which differ both in morphology and in oxidation degree. The results indicate a non-linear current-voltage relationship for all the investigated films. The extrapolated dielectric constant (") values of the investigated GRMs (GL and GO materials) agree with the experimental and theoretically predicted values reported in the literature ("~2-15). Because similar conductance values were obtained for the GL materials deposited on glass and silicon oxide substrates, no significant interactions of GL materials with the two different substrates were highlighted. These results are the starting point for boosting a feasible use of GL materials in a wide spectrum of applications, ranging from electronics to optics, sensors, membranes, functional coatings, and biodevices.

Refuse-Derived Fuels (RDFs) are segregated forms of wastes obtained by a combined mechanical-biological processing of municipal solid wastes (MSWs). The narrower characteristics, e.g., high calorific value (18-24 MJ/kg), low moisture content (3-6%) and high volatile (77-84%) and carbon (47-56%) contents, make RDFs more suitable than MSWs for thermochemical valorization purposes. As a matter of fact, EU regulations encourage the use of RDF as a source of energy in the frameworks of sustainability and the circular economy. Pyrolysis and gasification are promising thermochemical processes for RDF treatment, since, compared to incineration, they ensure an increase in energy recovery efficiency, a reduction of pollutant emissions and the production of value-added products as chemical platforms or fuels. Despite the growing interest towards RDFs as feedstock, the literature on the thermochemical treatment of RDFs under pyrolysis and gasification conditions still appears to be limited. In this work, results on pyrolysis and gasification tests on a real RDF are reported and coupled with a detailed characterization of the gaseous, condensable and solid products. Pyrolysis tests have been performed in a tubular reactor up to three different final temperatures (550, 650 and 750 C) while an air gasification test at 850 C has been performed in a fluidized bed reactor using sand as the bed material. The results of the two thermochemical processes are analyzed in terms of yield, characteristics and quality of the products to highlight how the two thermochemical conversion processes can be used to accomplish waste-to-materials and waste-to-energy targets. The RDF gasification process leads to the production of a syngas with a H2/CO ratio of 0.51 and a tar concentration of 3.15 g/m3.

In this study, matrix-assisted pulsed laser evaporation (MAPLE) was used to deposit graphene-like materials (GL), a new class of biocompatible graphene-related materials (GRMs) obtained from a controlled top-down demolition of a carbon black, on silicone slices to test their potential use as functional coating on invasive medical devices as indwelling urinary catheters. Results indicate that the relevant chemical-physical features of the deposit (controlled by FTIR and AFM) were maintained after MAPLE deposition. After deposition, GL films underwent a biological survey toward target cellular lines (murine fibroblast NIH3T3, human keratinocytes HaCAT and the human cervical adenocarcinoma epithelial-like HeLa). Results indicate that the GL films did not lead to any perturbations in the different biological parameters evaluated. The presented results and the possibility to further functionalize the GL or combine them with other functional materials in a hybrid fashion to assure a tighter adhesion onto the substrate for use in harsh conditions open the door to practical applications of these new-concept medical devices (drug delivery, next generation flexible devices, multifunctional coatings) paving the way to the prevention of nosocomial infections driven by catheterization through antibiotics-free approaches.

The deliverable 3.1 (D3.1) entitled Guidelines and Codes of good practices referring to the manufacturing processes of carbon nanomaterials (CNM) composites, was developed within the WG3 regarding novel CNM & new processing routes. At first, a brief overview of the different carbon-based nanomaterials with potential utilization in sensing applications is presented. Followed by the different methodologies used to prepare nanocomposites and fibre reinforced composites, along with their main properties. The main purpose of this document is to give a clear view of the drawbacks that limit the up-scale utilization of CNM composites and to provide principles and strategies for the maximization of their properties with the incorporation of these types of particles. This deliverable received contribution of some WG3 members.

Refuse Derived Fuels (RDFs) are generated from municipal solid wastes (MSWs) thought a combined mechanical-biological processing. The narrower chemico-physical characteristics make RDFs more suitable than MSWs for thermochemical valorisation purposes. For this reason EU regulations encourage the use of RDF as a source of energy in the frameworks of sustainability and circular economy. Pyrolysis and gasification are promising thermochemical processes for RDF treatment, since, with respect to incineration, they ensure an increase in energy recovery efficiency, a reduction of pollutants emissions, and the production of value-added products as chemical platforms or fuels. In this work, the results on pyrolysis tests on a real RDF rich in plastic- and cellulose-based materials are reported. Pyrolysis tests have been performed in a tubular reactor up to three final temperatures (550, 650 and 750°C) and the resulting gaseous, condensable and solid products have been analysed in terms of yield, chemico-physical characteristics and energy recovery to highlight how this thermochemical conversion process can be used to accomplish waste to materials and waste to energy targets. RDF pyrolysis produces three products (gas, char and pyrolysis oil) with specific chemico-physical characteristics exploitable in unconventional technological applications. Among the three products, the most abundant and also the most promising in terms of possible applications is the condensable species fraction, whose highest yield was achieved at 550°C. The massive presence of waxes makes this fraction a potential candidate for the replacement of fossil-fuel based material in bitumen and asphalt processing and rejuvenation. It is worth of noting also that the final pyrolysis temperature has a strong influence on the segregation of some critical species such as S and N in the char opening to its re-use as adsorbent, catalyst, material for energy harvesting devices and additives for pavement industry depending on its composition. The use of pyrolysis products for asphalt preparation is an emerging research topic and opens to an alternative use of pyrolysis products (liquids and solids) outside of fuel and chemicals industries and to the replacement of petroleum-derived products (e.g. crude oil) with products deriving from waste thermoconversion.

Introduction: A number of experimental and modeling works are continuously ongoing on the pyrolysis of biomass as well as of their single organic components (cellulose, hemicellulose and lignin) for assessing at which extent the variability of the biomass composition, in terms of both organic and inorganic matrices, affects the pyrolysis characteristic temperatures and products yields. Despite its abundance in plants (about 20-30 wt.%), hemicellulose pyrolysis is scarcely studied because of its chemical heterogeneity, complexity and less defined structure. Moreover, the hemicellulose isolation techniques can induce polymer modifications and cause salts inclusions, thus making even harder the understanding of the pyrolytic behaviour of this complex polymer. Aim: A research activity devoted to the characterization of hemicellulose pyrolytic behaviour under slow pyrolysis conditions has been carried out since a few years, taking into account also the effect of AAEMs presence. This work aims at elucidating the mechanisms involved in the pyrolysis of xylan-based hemicellulose, emphasizing the role of the inorganics and of the composition and the structure of the polymeric chain. Methods: Two commercially available xylans isolated from beechwood (BW X) and corncob (CC X) and one hemicellulose extracted from grape pruning residues (GP X) have been selected. The hemicellulose was extracted through alkaline treatment after a proper purification and its structure was fully characterized. The thermal behaviour of the BW X, CC X and GP X samples has been evaluated by thermogravimetric (TG) analysis and slow pyrolysis tests have been performed up to 700 °C. Weight loss profiles and gas release rates as a function of the temperature have been compared and the differences between products yields, gas composition and the yields of the main liquid species have been discussed. Results: The results of TG analyses indicate that the GP X follows a different reaction pathway characterized by a lower weight loss rate with respect to BW X and CC X during the main devolatilization stage. Consistently, higher yields of char have been obtained from the GP X pyrolysis. At the same time, high amounts of gaseous species (CO, CO2 and H2) have been produced and a lower yield of the liquid product has been obtained. Conclusion: Since the GP X sample has the highest ash content it is likely that the observed differences were due to the catalytic effect of alkali metals, well known in cellulose pyrolysis, on the ring scission reactions with the consequent formation of light gases. However, the composition and the structure of the starting material may contribute to the differences in char yields. The comparison between the raw and demineralized samples is now ongoing to highlight the relative role of ashes and of the polymer composition and structure.

A detailed investigation on the slow pyrolysis of xylose-based materials was conducted since many years in our group to shed light on the pyrolytic behavior of hemicellulose and identify and circumscribe the role of structural characteristics and alkali and alkaline earth metals on hemicellulose decomposition mechanisms. Studies on three xylose-based hemicelluloses differing in composition, molecular weight (MW), chain branching, monomers composition and origin, indicated that: i) the production of char and gaseous species is promoted by higher MW, branching and composition with the ashes playing a prominent role; ii) the production of anhydrosugars, furfural, formic acid and acetic acid is suppressed by the presence of ashes, while the chain branching seems to favor the production of linear ketones and to inhibit the production of cyclic and hydroxylated ketones; iii) the production of water seems to be favored by the increase of MW and branching and suppressed by the presence of ashes. Studies on demineralized and metal doped xylan samples led to the acquisition of details regarding the catalytic effects of alkali and alkaline earth metals on hemicellulose pyrolysis behavior. The comparison of the results of pyrolysis tests on a demineralized xylan (DX) sample and a raw commercial xylan (X) indicated that metal ions in X were responsible of: i) a slight anticipation of the initial decomposition temperature and of the presence of a second important event (peaked at 550 K) in the devolatilization curve that is only slightly visible at higher temperature in the DX decomposition curve; ii) a higher amount of solid residue compared to the demineralized sample. The results of pyrolysis tests on samples obtained by doping a demineralized xylan through cationic exchange with controlled amounts of K+ (from 0.3 to 1.2 wt.%) or Na+ (from 0.4 to 1.1 wt.%) allowed to define the specific catalytic effects of K+ and Na+. The experimental results showed that K+ and Na+ have similar catalytic effects: both Na+ and K+ catalyze ring opening reactions (increasing the production of CO2, CO and hydroxy-ketones) and the rearrangement of the xylose ring to form furan derivatives. In the end, the comparison of above reported results with those of pyrolysis tests on a set of doped xylan samples obtained introducing controlled amounts of KCl or NaCl on a demineralized xylan sample through a conventional wet impregnation approach demonstrated how the catalytic effect of alkali metals on xylan pyrolysis is also affected by the adopted doping approach. The results showed that the introduction of K+ by wet impregnation using a chloride salt negligibly affected the pyrolytic behavior of the demineralized sample and indicated that the doping approach based on wet impregnation using chloride salts is not appropriate for the study of the effect of alkali metals on the pyrolysis of polysaccharides bearing acidic functional groups as xylan.

The ability to measure and monitor the concentration of specific chemical and/or gaseous species (i.e., "analytes") is the main requirement in many fields, including industrial processes, medical applications, and workplace safety management. As a consequence, several kinds of sensors have been developed in the modern era according to some practical guidelines that regard the characteristics of the active (sensing) materials on which the sensor devices are based. These characteristics include the cost-effectiveness of the materials' manufacturing, the sensitivity to analytes, the material stability, and the possibility of exploiting them for low-cost and portable devices. Consequently, many gas sensors employ well-defined transduction methods, the most popular being the oxidation (or reduction) of the analyte in an electrochemical reactor, optical techniques, and chemiresistive responses to gas adsorption. In recent years, many of the efforts devoted to improving these methods have been directed towards the use of certain classes of specific materials. In particular, ionic liquids have been employed as electrolytes of exceptional properties for the preparation of amperometric gas sensors, while metal-organic frameworks (MOFs) are used as highly porous and reactive materials which can be employed, in pure form or as a component of MOF-based functional composites, as active materials of chemiresistive or optical sensors. Here, we report on the most recent developments relative to the use of these classes of materials in chemical sensing. We discuss the main features of these materials and the reasons why they are considered interesting in the field of chemical sensors. Subsequently, we review some of the technological and scientific results published in the span of the last six years that we consider among the most interesting and useful ones for expanding the awareness on future trends in chemical sensing. Finally, we discuss the prospects for the use of these materials and the factors involved in their possible use for new generations of sensor devices.

The detection of gaseous oxygen (O2) in gas mixtures is relevant for air quality control, packaging, life sciences, automotive industry, and chemical industry. Starting from previous literature results on the ability of TiO2 nanostructures to act as a photoluminescence-based probe of O2, in this work we explored the possibility to produce a mesoporous mixed-phase TiO2 by using a metal organic framework (MOF) as sacrificial template and to test it as dual-emitting O2 optical probe. Mesoporous TiO2 containing both anatase and rutile crystalline phases was produced starting from a 1,4-benzenedicarboxylate (BDC)-based MOF containing Ti as metallic center (MIL125-(Ti)). Two different calcination temperatures were explored with the aim of modulating the ratio between the two crystalline phases. The obtained samples were characterized by TGA, SEM, HRTEM, N2 adsorption- desorption isotherms, XRD, FTIR, XPS and photoluminescence (PL) spectroscopies. Their capacity to act as doubly-parametric O2 optical sensor was evaluated by measuring PL intensity changes during O2 exposure (Fig.1). In particular, the time dynamics of the PL modulation for VIS-PL and NIR-PL emission bands were investigated by measuring PL spectra during exposure to flowing Air-N2 mixtures at different relative concentrations. The results showed that the MOF-derived samples exhibited responses to air densities in the 2-20% range. Future work will be focused on the detection of lower concentrations of O2 and to improve the responsivity of both NIR- and VIS-PL components also by metal doping.