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Cement composites containing different carbon nanomaterials, namely graphene technical grade, graphene super grade, and graphene oxide, up to 1.0% by weight of cement, were prepared. Ultrasonic, chemical, and thermochemical treatments were applied to improve the stability of the dispersions containing the graphene-based nanomaterials. Their exfoliation was analyzed using Raman spectroscopy, and the stability of the dispersions was quantitatively investigated by means of the static multiple light scattering (SMLS) technique. The sonication process enhanced the intensity of the 2D band of graphene technical grade, suggesting a partial degree of exfoliation, while the hydrothermal treatment with sodium cholate significantly promoted the stability of its dispersion. The effect of the addition of selected graphene-based nanomaterials in mortars was evaluated in terms of fresh state properties, mechanical strength, capillary water absorption, and pore size distribution. Workability decreased with the increase in the amount of carbon nanomaterials. Field emission scanning electron microscopy (FESEM) was also employed to characterize the microstructure of pristine graphene-based nanomaterials and their inclusion within the cement matrix. Our results suggest that mechanical properties are only moderately affected by the inclusion of all additives, whereas the introduction of graphene significantly influences the coefficient of capillary water absorption. Specifically, a reduction of about 20% in the capillary water absorption coefficient was observed at the concentration of 1.0 wt% of graphene technical grade, which is ascribed to a refinement of the porosity. [ABSTRACT FROM AUTHOR]

This work presents the results of the study of a fragment of architectural terracruda sculpture from the Buddhist archaeological site of Tepe Narenj (Kabul, Afghanistan, fifth-ninth centuries CE) through X-ray micro-computed tomographic analysis. This technique offers great potential for the study of artworks that, due to their nature, condition, or relevance, are not suitable for sampling. The results have provided useful data for understanding the making of the sculpture showing for the first time the relevance of materials of plant origin used in the composition of the clay-based body, a feature that had not been previously highlighted and which appears to be crucial for proposing suitable conservation interventions. [ABSTRACT FROM AUTHOR]

The target for European decarburization encourages the use of renewable energy sources and H2 is considered the link in the global energy system transformation. So, research studies are numerous, but only few facilities can test materials and components for H2 storage. This work offers a brief review of H2 storage methods and presents the preliminary results obtained in a new facility. Slow strain rate and fatigue life tests were performed in H2 at 80 MPa on specimens and a tank of AISI 4145, respectively. Besides, the storage capacity at 30 MPa of a solid-state system, they were evaluated on kg scale by adsorption test. The results have shown the H2 influence on mechanical properties of the steel. The adsorption test showed a gain of 26% at 12 MPa in H2 storage with respect to the empty condition. All samples have been characterized by complementary techniques in order to connect the H2 effect with material properties. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) in conjunction with an increasing use of renewables provides a clean pathway to sustainable development and climate change mitigation. In selecting a low temperature CCS adsorbent, parameters such as selectivity, regeneration energy, and economicity play a crucial role. Poly(L‐lactide) (PLA) is one of the most promising materials in science and engineering, not only because it is a green polymer progressively replacing petrobased plastics, but also for its carbon dioxide (CO2)‐philic nature that makes it a suitable candidate for greenhouse gas capture and climate change mitigation. Literature data point to PLA as a valid CCS candidate, although no direct gaseous CO2 adsorption investigation or with mild preparation/regenerative energy was reported. In the present experimental work, a deeper investigation of the adsorption/desorption properties of PLA in presence of gaseous CO2 at room temperature was undertaken by means of a home‐made Sievert‐type apparatus. The effects of pressure (0–15 bar), morphology (commercial pellets, powder, and flakes), and regenerative energy (303 and 333 K) were investigated. PLA samples were also characterized by helium picnometry to obtain skeletal density and by XRD and SEM to obtain morphological and structural information. Results show that PLA represents a valid and ecological alternative among the materials for the capture of CO2. The PLA absorption capacity reaches 16 wt% at 15 bar and 303 K, and is closely linked to the thermal treatment, morphology, and crystalline structure of the material. [ABSTRACT FROM AUTHOR]

Lead zirconium titanate PbZr0.53Ti0.47O3 (PZT) thin films have been obtained by sol-gel synthesis, deposited on different substrates [float glass, indium tin oxide (ITO)-coated float glass, and intrinsic silicon wafer], and later subjected to different thermal treatments. The morphologic and the structural properties of both PZT thin films and substrates have been investigated by scanning electron microscope and their composition was determined by energy dispersive x-ray (EDX) analysis. Moreover, variable angle spectroscopic ellipsometry provides relevant information on the electronic and optical properties of the samples. In particular, the optical constant dispersion of PZT deposited on ITO-coated float glasses shows a small absorption resonance in the near IR region, not observed in PZT films deposited on the other substrates, so that such absorption resonance can be explained by interfacial effects between ITO and PZT layers. This hypothesis is also supported by EDX measurements, showing an interdiffusion of lead and indium ions, across the PZT-ITO interface, that can generate a peculiar charge distribution in this region. [ABSTRACT FROM AUTHOR]

The synthesis, morphologic and the structural properties of lead zirconium titanate Pb[Zr.sub.0.53][Ti.sub.0.47][O.sub.3] (PZT) thin films deposited on different substrates such as float glass, indium tin oxide (ITO)-coated float glass, and intrinsic silicon wafer are described. A small absorption resonance in the near infrared (IR) region observed for the optical constant dispersion of PZT deposited on ITO-coated float glasses is explained by interfacial effects between ITO and PZT layers.

In this study, sustainable nanoporous carbon materials that are efficient, renewable, cost-effective and adaptable were developed. These microporous feature carbon adsorbents were synthesized utilizing a straightforward and efficient method. Plum stones are residual fruit materials that offer a financially feasible and sustainable carbon source with exceptional porosity and desirable elemental composition. The plum stones underwent carbonization and were subsequently chemically modified with polyaniline nanofibers and then subjected to chemical activation using different activating agents. This yielded sustainable nanoporous carbon with a high degree of porosity, in conjunction with doping with precious high electron density elements such as O, N and S. The sustainable nanoporous carbons that have been developed exhibits exceptional microporosity, with BET-SSA of 1705 m2 g−1 and a pore volume of 0.726 cm3 g−1, besides, the dominance of ultramicropores of 0.6 nm size. This in addition to convenient doping of oxygen, nitrogen and sulfur elements which are crucial for H 2 uptake. The developed nanoporous carbon demonstrated highly promising capabilities for storing H 2 molecules at cryogenic and ambient temperatures. The sustainable adsorbent achieved hydrogen storage capacities of 4.63 and 0.45 wt% at 77, 296 K, and a pressure of 40 and 80 bar, respectively. This H 2 storage capacity at RT is often regarded as one of the highest reported in the literature for nanoporous adsorbents. Moreover, study investigated the separation selectivity of developed adsorbents for CO 2 /H 2 based on uptake ratio at 30 bar and RT. The results demonstrated a significant separation selectivity reaching a value of 382.5 for the CO 2 /H 2 , which is regarded as one of the most elevated values documented in the existing literature for nanoporous carbon materials. Thus, the presented sustainable nanoporous materials have shown great promise for hydrogen storage, pre-combustion CO 2 capture and H 2 purification applications at ambient temperature. • Sustainable and cost-effective microporous carbons were developed. • Plum stones and their composites with nanofibers were used as renewable carbon precursor. • Efficient nanoporous carbon with high SSA and doped with precious heteroatoms were developed. • Ultra-micropores doped with O and N were engineered for high H 2 uptake at RT. • Outstanding H 2 uptake values of 4.63 and 0.45 wt% at 77, 296 K, were achieved. [ABSTRACT FROM AUTHOR]

Activated carbons exhibit a high grade of porosity, which together with structural stability, regenerability and cyclability makes them capable of achieving excellent hydrogen adsorption capacity. A further advantage comes from the ease of production and the use of recyclable and biocompatible materials. A simple way to produce activated carbons from amorphous cellulose involves procedures in which a pyrolysis process is combined with physical activation in CO 2. We used this approach by optimizing the production process tuning the activation times. The aim is to evaluate the influence of this process parameter on the formation of the specific surface area, the pore volume and fraction of micropores with a typical size <2 nm. The influence of these structural parameters on the hydrogen adsorption properties was then evaluated. The textural and adsorption characteristics were investigated using a commercial volumetric apparatus (ASAP 2460, Micromeritics) at −196 °C and pressures between 0 and 1 bar, while the morphological properties were investigated using scanning electron microscopy. The results show that the nanostructured samples are characterized by a very high degree of ultra-microporosity (<0.7 nm) with an average pore size between 0.5 and 0.6 nm and a high specific surface area, reaching maximum values around 1500 m2/g and micropore volume up to 0.58 cc/g. These morphological characteristics strongly influence the hydrogen adsorption properties, where the molecules adsorbed reach values very close to the coverage of ideal monolayer. The synthesized activated carbon samples show a higher hydrogen adsorption capacity than similar commercial materials tested under the same thermodynamic conditions. [Display omitted] • Easily tuning of ultra-microporosity. • Precursor influence on storage performance. • Hierarchical porous carbons and possibility hydrogen storage at low pressure. • Fully reversible hydrogen physisorption. • Amorphous cellulose as sustainable solution. [ABSTRACT FROM AUTHOR]