Paolo Sgarbossa

Understanding how fluorinated contaminants interact with porous carbonaceous materials requires to gain insights beyond macroscopic uptake metrics, particularly when heterogeneous pore networks and surface chemistries imply multiple mobility states. Here, we introduce a dynamic-signature approach to rank biochar-fluorinated liquid interactions based on molecular mobility states probed by 19F fast field-cycling (FFC) NMR relaxometry. Two fluorinated model systems, a perfluoropolyether mixture (Galden HT70) and the small-molecule perfluorodecalin (PFD), were investigated as neat liquids and after contact with two activated biochars (APN1 and LP39) characterized by diverse pore architectures and surface chemistries. Inverse Laplace transform (ILT) analysis of selected relaxation decays reveals the emergence of interfacial and confinement-related heterogeneity upon biochar contact, whereas quantitative analysis of 19F nuclear magnetic relaxation dispersion (NMRD) profiles using a two-term rotational–translational model yields effective dynamic parameters that encode these interactions. APN1, a predominantly microporous and alkaline carbon, induces moderate perturbations consistent with partial interfacial exchange and confinement, whereas LP39, a high-surface area, mesopore-richer and acidic carbon, produces strongly dispersive NMRD signatures indicative of restricted diffusion and enhanced surface-driven relaxation. These trends are consistent across both fluorinated probes, demonstrating that the observed dynamic signatures primarily reflect biochar physicochemical properties rather than probe-specific chemistry. Overall, the results show that activated biochars can be mechanistically typified by their ability to redistribute fluorinated molecules among bulk-like, interfacial, and confined dynamic states. The dynamic-signature approach presented here provides a complementary, mechanistically grounded perspective to conventional adsorption metrics and offers a pathway toward rational selection of biochars for fluorinated-contaminant retention.

Polyamide 12 (PA12) is a widely employed feedstock material in industrial additive manufacturing (AM) technologies. Despite this, there is limited epidemiological evidence regarding its health effects, raising particular concern about the potential implications for workers exposed to it. The present study evaluates PA12 in two exposure scenarios: via a laboratory simulation of powder-handling tasks associated with powder bed fusion processes and during active filament-based material extrusion 3D printing. Characterization of particle emissions was carried out through an integrated experimental approach that combined real-time measurements, morphological and elemental analyses, and in vitro cytotoxicity screening of virgin powder. The investigation was performed according to the multimetric tiered approach proposed by the Organization for Economic Cooperation and Development (OECD). Real-time instruments were used to measure particle number concentration, average diameter, and lung deposited surface area, while samples were collected for subsequent off-line analyses. The results reported elevated levels of airborne particles compared to the background in both applications, with emissions characterized as larger micrometric particles (approximately 20 μm) during powder handling and as smaller aggregates of submicrometric components during filament-based extrusion. Preliminary in vitro testing revealed no significant cytotoxic response or alterations in gene expression profiles in human bronchial epithelial cells (HBEC3-KT) when exposed to PA12 virgin powder. Such findings will be useful to develop precautionary hazard measures and appropriate control strategies to ensure the safe use of PA12 3D printing applications in occupational settings.

The coffee industry and landfill leachate treatment produce waste: spent coffee grounds (SCG) and landfill leachate membrane concentrate (LLMC). Current disposal methods, such as open burning, incineration, and landfilling, waste resources and hinder sustainability. Due to their high pollution potential, cost-effective management solutions are urgently needed. This research explores the slow pyrolysis of SCG using potassium hydroxide (KOH) and LLMC as activating agents (1:1 weight ratio). LLMC’s high alkali and alkaline earth metal content may enhance char activation and improve char quality. Using LLMC as an activating agent offers an alternative to value SCG and landfill waste, potentially replacing industrial-scale activators like steam, CO2, and chemical additives. SCG had a low specific surface area (4.5 m2 g-1), contrasting with the notable surface areas observed in both activated chars. In particular, the KOH-activated char exhibited a higher surface area than the LLMC-activated char, measuring 1.960 m2 g-1 compared to 1.138 m2 g-1 - a difference of about 72%. On the other hand, the combustion enthalpy of the LLMC-activated material was estimated at 22.04 MJ kg-1. The combustion enthalpy of LLMC-activated char was about 21.7% and 19.8% higher than that of SCG and KOH-activated chars, which had values of 18.11 and 18.40 MJ kg-1, respectively. This work showed that both activated chars had superior energetic and morphological properties compared to non-activated chars made from SCG biomass. Among the activating agents, KOH led to better performance in terms of char yield and morphological properties. Meanwhile, utilizing LLMC as an activating agent highlights its potential for converting landfill waste into high-value material.

Tetroxides of Group 4 elements are benchmark catalysts for aldol reactions and oxidation processes, achieving high yields and regio‐, diastereo‐, and enantioselectivities. Our computational analyses and experimental studies, performed in solution and solid, consistently reveal that these tetroxides form attractive interactions with lone pair compounds exhibiting distinctive σ‐hole bond features. We propose naming these novel bondings as titan bonds (TnBs). These new insights into Ti/Zr/Hf tetroxide interactions may significantly aid in designing more effective catalysts with enhanced selectivities.

Tetroxides of Group 4 elements are benchmark catalysts for aldol reactions and oxidation processes, achieving high yields and regio‐, diastereo‐, and enantioselectivities. Our computational analyses and experimental studies, performed in solution and solid, consistently reveal that these tetroxides form attractive interactions with lone pair compounds exhibiting distinctive σ‐hole bond features. We propose naming these novel bondings as titan bonds (TnBs). These new insights into Ti/Zr/Hf tetroxide interactions may significantly aid in designing more effective catalysts with enhanced selectivities.

The preparation and use of iron oxide magnetic nanoparticles for water remediation is a widely investigated research field. To improve the efficacy of such nanomaterials, different synthetic processes and functionalization methods have been developed in the framework of green chemistry to exploit their magnetic properties and adsorption capacity in a sustainable way. In this work, iron oxide magnetic nanoparticles embedded in cross-linked sodium alginate beads designed to clean water from metal ions were magnetically characterized. In particular, the effect of copper adsorption on their magnetic properties was investigated. The magnetic characterization in a DC field of the beads before adsorption showed the presence of a superparamagnetic state at 300 K—a state that was also preserved after copper adsorption. The main differences in terms of magnetic properties before and after Cu²⁺ adsorption were the reduction of the magnetic signal (observed by comparing the saturation magnetization) and a different shape of the blocking temperature distribution obtained by magnetization versus temperature measurements. The evaluation of the reduction in magnetization can be important from the application perspective since it can affect the efficiency of the beads’ removal from the water medium after treatment.

Understanding how soil formation processes influence the microstructure and the dynamic behavior of clay‐rich materials is essential for both pedological interpretation and technological assessment. In this study, we applied fast field cycling nuclear magnetic resonance (FFC NMR) relaxometry to investigate the microstructural heterogeneity of Moroccan clays developed under diverse pedogenetic conditions. Nuclear magnetic relaxation dispersion (NMRD) profiles were processed using a model‐free inversion algorithm to retrieve the distribution of correlation times. The latter provides a phenomenological mapping of proton–surface interactions across distinct dynamic domains. Complementary indicators of micro‐scale hydrological connectivity were, then, computed from the T₁ distributions, integrating both structural (SCI) and functional (FCI) heterogeneity. While the former indicates the breadth of molecular environments experienced by water across the system, the latter captures the dynamic contrast between fast‐ and slow‐relaxing populations associated with variations in surface accessibility and magnetic heterogeneity. The results showed that the clay sample from Khemisset exhibited the greatest relaxation heterogeneity, consistent with advanced pedogenetic reorganization related to redox‐driven redistribution of paramagnetic metals. In contrast, the clay samples from Berrechid and Tiflet displayed a more ordered architecture and lower magnetic heterogeneity, reflecting earlier‐stage pedogenetic development. This study demonstrated that FFC NMR relaxometry reveals the microstructural memory encoded into water dynamics, offering a powerful tool to infer the pedogenetic pathways leading to soil formation. Beyond its relevance for pedological studies, the method also offers valuable insights into the technological behavior of clays, supporting the selection of raw materials for industrial purposes based on their microstructural properties.

Despite efforts to recycle, boro-alumino-silicate pharmaceutical glass (BASG) results in a significant portion of glass cullet currently landfilled. Highly contaminated fractions of BASG cullet are largely unemployed because of the presence of metals in their composition that prevents recycling. This waste glass can be eligible to produce sustainable alkali-activated materials (AAMs) reducing at the same time consumption of raw materials and CO₂ emissions. The ‘weak’ alkaline attack (NaOH < 3 M) determines the gelation of glass suspensions. Condensation reactions occur in hydrated surface layers, leading to strong bonds (Si-O-Si, Al-O-Si, etc.) between individual glass particles. Alkali are mostly expelled from the gel due to the formation of water-soluble hydrated carbonates. Microwave treatment has been implemented on samples after precuring at 40 °C, saving time and energy and achieving better mechanical properties. To improve the stability and reduce the release of glass components into solution, the consolidated monoliths were subjected to boiling/drying cycles. The chemical stability, cytotoxicity and antibacterial behavior of the final products have been investigated with the purpose of obtaining new competitive and sustainable materials. For further stabilization and for finding new applications, the activated and boiled samples can be fired at low temperature (700 °C) to obtain, respectively, a homogeneous foam or a compact material with glass-like density and microstructure.