Giuseppe Prenesti

A confined-fluidized bed was investigated as a dynamic adsorber-regenerator for CO₂ capture using amino-functionalized mesoporous silica (APTES20). Adsorption, gas switching, in situ temperature-swing desorption and cooling were repeated in the same reactor without sorbent transfer. In one 68-cycle series, the fitted adsorption-capacity trend decreased by approximately 1.5%; individual-cycle scatter and the absence of independent replicate series limit inference about long-term material lifetime. The results demonstrate cyclic operation over the tested window, not industrial-scale durability.

In this work, we develop a simple and scalable fabrication method for the preparation of stable and efficient self‐heating membranes that combine the excellent photothermal conversion efficiency of graphene oxide (GO) and the hydrophilic properties of polyvinyl alcohol (PVA) for photothermal membrane distillation (PMD) applications. Our results demonstrated that Janus composite membranes comprising a thin layer of GO‐loaded PVA hydrogel on a porous polyvinylidene fluoride (PVDF) support can offer a dual advantage: the hydrophilic GO‐loaded hydrogel provides localized heating under light irradiation and resistance to scaling, while the hydrophobic substrate offers excellent wetting resistance and allows water evaporation under thermal gradients. As a result, a 190% flux increase with 99.99% salt rejection was achieved for a 35 g L ⁻¹ NaCl feed solution under 1 sun irradiation with 2 wt.% GO‐filled composites, achieving a photothermal conversion efficiency of 70% and a specific thermal energy consumption approximately 25% lower than the latent heat of evaporation of water at the operating temperature. Detailed computational fluid dynamics (CFD) simulations allowed us to evaluate the thermal profiles across the membrane module and calculate the temperature polarization coefficient (TPC) that ranged from 0.8 to 1.2 for the light ON‐state. Our results also demonstrated the fundamental dependence of process performance on solution velocity and GO loading, which establishes a key tradeoff for the efficient applicability of this technology to water desalination.

This study undertakes a thorough examination of hydrogen solubility within various metal-alloy membranes, including those based on palladium (Pd), vanadium (V), niobium (Nb), tantalum (Ta), amorphous alloys and liquid gallium (Ga). The analysis aims to outline the strengths and weaknesses of each material in terms of solubility and permeability performance. The investigation began by acknowledging the dual definitions of solubility found in literature: the “secant method”, which calculates solubility based on the hydrogen pressure corresponding to a specific sorbed hydrogen loading, and the “tangent method”, which evaluates solubility as the derivative (differential solubility) of the sorption isotherm at various square root values of hydrogen partial pressure. These distinct methodologies yield notably different outcomes. Subsequently, a compilation of experimental data for each membrane type is gathered, and these data are re-analysed to assess both solubility definitions. This enabled a clearer comparison and a deeper analysis of membrane behaviour across different conditions of temperature, pressure, and composition in terms of hydrogen solubility in the metal matrix. The re-evaluation presented in this study serves to identify the most suitable membranes for hydrogen separation or storage, as well as to pinpoint the threshold of embrittlement resulting from hydrogen accumulation within the metal lattice. Lastly, recent research has indicated that particularly promising membranes are those fashioned as “sandwich” structures using liquid gallium. These membranes demonstrate resistance to embrittlement while exhibiting superior performance characteristics.

Understanding the early-stage physical interactions between polymeric membranes and supersaturated salt solutions is crucial for advancing membrane-assisted crystallization (MCr) processes. In this study, we employed molecular dynamics (MD) simulations to investigate the short-term morphological response of an isotactic polypropylene (PP) membrane in contact with LiF solutions at different concentrations (5.8 M and 8.9 M) and temperatures (300–353 K), across multiple time points (0, 150, and 300 ns). These data were used as input for computational fluid dynamics (CFD) analysis to evaluate structural descriptors of the membrane, including tortuosity, connectivity, void fraction, anisotropy, and deviatoric anisotropy, under varying thermodynamic conditions. The results show subtle but consistent rearrangements of polymer chains upon exposure to the hypersaline environment, with a marked reduction in anisotropy and connectivity, indicating a more compact and isotropic local structure. Surface charge density analyses further suggest a temperature- and concentration-dependent modulation of chain mobility and terminal group orientation at the membrane–solution interface. Despite localized rearrangements, the membrane consistently maintains a net negative surface charge. This electrostatic feature may influence ion–membrane interactions during the crystallization process. While these non-reactive, short-timescale simulations do not capture long-term degradation or fouling mechanisms, they provide mechanistic insight into the initial physical response of PP membranes under MCr-relevant conditions. This study lays a computational foundation for future investigations bridging atomistic modeling and membrane performance in real-world applications.

The recovery of lithium from extracts obtained from a black mass of spent lithium-ion batteries treated with a ternary solvent system at acidic pH was investigated using flat-sheet nanofiltration (NF) membranes operated according to a dead-end configuration. Specifically, four samples obtained at different pH values (2.5 and 5) and extraction times (48, 96 and 168 h) were treated in selected operating conditions by using two commercial polymeric membranes (denoted DK and HL, with an approximate molecular weight cut-off of 150–300 Da) up to a volume reduction factor (VRF) of 4. Membrane performance was assessed in terms of productivity and selectivity towards specific ions, including lithium. For most treated samples, the HL membrane exhibited higher permeate fluxes in comparison to the DK membrane. However, the DK membrane performed better in terms of lithium rejection than the HL membrane, with a negative rejection at VRF 4 observed for all treated samples. More than 90% of multivalent ions were rejected by both membranes independently of the VRF. The membrane ability to retain multivalent ions led to their progressive concentration in the retentate as the VRF increased. The extraction time did not impact the NF performance of both membranes in terms of ion rejection. For the DK membrane conditions of extraction of 96 h and pH 5 represented the best trade-off between flux, ion rejection, and total lithium recovery.

This paper focuses on a morphological study of the MnTe-like structures, carried out by the evaluation of the tortuosity tensor and other related parameters using a computational fluid dynamics approach recently developed by our research group. The present work focuses on all possible crystals—existing or not developed yet—having the same structure as that of the manganese telluride. This analysis provides new information not present yet in the open literature. The motivation behind this study lies in the importance of this type of structure in physics and material science. In particular, the structures investigated are anisotropic and bi-disperse, with two independent geometrical parameters controlling the structure shape: the ratio of the particle diameters (r₁) and the normalised inter-particle distance (r₂). Exploiting this fact, several different structures of the same family are created, changing these two parameters independently, also allowing inter-penetration of particles to enlarge the study’s applicability. The results are primarily obtained in terms of the tortuosity tensor, needed to catch and quantify the anisotropy of the structures. Then, other morphological parameters, such as connectivity, principal diffusion directions, and anisotropy factors, are evaluated, obtaining in this way a novel morphological characterisation of the structure. It is found that high values of tortuosity are observed at lower and higher values of {r₁, r₂}, which means that there exists a minimum value between them. Additionally, the anisotropy factor is found to be higher at lower values of {r₁, r₂} and lower at higher ones. This is in accordance with the fact that, as the inter-particle distance and the ratio between particle diameters increase, the structure enlarges, which implies a lower influence of the particle distribution and, thus, a gradually more isotropic structure.