Iron Oxide Nanoparticle-Assisted Delamination of Ti3C2Tx MXenes: A New Approach to Produce Magnetic MXene-Based Composites.

Ti3C2Tx MXene is one of the most comprehensively studied 2D materials in terms of its adsorptive, transport, and catalytic properties, cytotoxic performance, etc. Still, conventional MXene synthesis approaches provide low single-flake MXene yield and frequently uncontrollable properties, demanding further post-processing. The MXene family also lacks magnetism, which is helpful for producing effective nanoadsorbents as their magnetic decantation is the cheapest and most convenient way to remove the spent adsorbent from water. Composite materials consisting of magnetic nanoparticles grown on top of MXene flakes are commonly used to provide magnetic properties to the resulting nanocomposite. In this paper, we study the possibility to delaminate multilayer Ti3C2Tx MXene sheets directly by growing iron oxide magnetic nanoparticles inside their interlayer spacing. We find out that, with a mass fraction of particles comparable or exceeding that of MXenes, their growth is accompanied by an effective enhancement of single-layer MXene yield and suitable magnetic properties of the resulting composite. The developed approach can be further used for simplifying synthesis protocols to obtain magnetic MXene-based nanoadsorbents with tunable properties.

Valorization and Potential Antimicrobial Use of Olive Mill Wastewater (OMW) from Italian Olive Oil Production.

The production of olive oil generates olive mill wastewater (OMW) which essentially derives from the processing, treatment and pressing of olives in mills. Traditional milling processes require a quantity of water varying between 40 and 120 L per quintal of pressed olives, generating a considerable amount of wastewater. It is thus necessary to reduce process water and enhance its use to implement the concept of a circular economy. To this end, our preliminary work was dedicated to water purification by means of suitable and efficient filtration systems. The microfiltered OMW was firstly concentrated through reverse osmosis. Then, an additional concentration step was carried out via vacuum membrane distillation using hydrophobic hollow fiber membranes. The application of the membrane-based processes allowed the recovery of a purified water and the concentration of valuable polyphenols in a smaller volume. The different fractions obtained from the purification have been tested for the determination of the antioxidant power (DPPH assay) and dosage of polyphenols (Folin-Ciocalteu assay) and were characterized using IR spectroscopy. All samples showed relevant antioxidant activity (percentage range: 10-80%) and total phenolic content in the 1.5-15 g GAE/L range. The obtained fractions were tested for their antimicrobial effect on numerous clinical isolates of Gram-positive and Gram-negative species, resistant and multi-resistant to current antibiotic drugs. OMW samples showed widespread activity against the considered (phyto)pathogens (MIC range 8-16 mg/mL) thus supporting the value of this waste material in the (phyto)pharmaceutical field.

Efficacy of High-Ozonide Oil in Prevention of Cancer Relapses Mechanisms and Clinical Evidence.

BACKGROUND: Cancer tissue is characterized by low oxygen availability triggering neo angiogenesis and metastatisation. Accordingly, oxidation is a possible strategy for counteracting cancer progression and relapses. Previous studies used ozone gas, administered by invasive methods, both in experimental animals and clinical studies, transiently decreasing cancer growth. This study evaluated the effect of ozonized oils (administered either topically or orally) on cancer, exploring triggered molecular mechanisms. METHODS: In vitro, in lung and glioblastoma cancer cells, ozonized oils having a high ozonide content suppressed cancer cell viability by triggering mitochondrial damage, intracellular calcium release, and apoptosis. In vivo, a total of 115 cancer patients (age 58 ± 14 years; 44 males, 71 females) were treated with ozonized oil as complementary therapy in addition to standard chemo/radio therapeutic regimens for up to 4 years. RESULTS: Cancer diagnoses were brain glioblastoma, pancreas adenocarcinoma, skin epithelioma, lung cancer (small and non-small cell lung cancer), colon adenocarcinoma, breast cancer, prostate adenocarcinoma. Survival rate was significantly improved in cancer patients receiving HOO as integrative therapy as compared with those receiving standard treatment only. CONCLUSIONS: These results indicate that ozonized oils at high ozonide may represent an innovation in complementary cancer therapy worthy of further clinical studies.

A Single Step Preparation of Photothermally Active Polyvinylidene Fluoride Membranes Using Triethyl Phosphate as a Green Solvent for Distillation Applications.

Membrane distillation is a growing technology that can address the growing problem of water shortage. The implementation of renewable energy and a reduction in the environmental impact of membrane production could improve the sustainability of this process. With this perspective, porous hydrophobic polyvinylidene fluoride (PVDF) membranes were prepared using triethyl phosphate (TEP) as a green solvent, using the non-solvent induced phase separation technique. Different amounts of carbon black were added to dope solutions to improve the photothermal properties of the membranes and to enable direct heating by solar energy. By optimizing the preparation conditions, membranes with porosity values as high as 87% were manufactured. Vacuum membrane distillation tests carried out using a concentrated NaCl solution at 50 °C showed distillate fluxes of up to 36 L/m2 h and a complete salt rejection. Some preliminary studies on the photothermal performance were also conducted and highlighted the possibility of using such membranes in a direct solar membrane distillation configuration.

Treatment of Olive Mill Wastewater through Integrated Pressure-Driven Membrane Processes.

The disposal of wastewater resulting from olive oil production (olive mill wastewater, OMW) is a major issue for olive oil producers. This wastewater is among the most polluting due to the very high concentration of organic substances and the presence of hardly degradable phenolic compounds. The systems proposed for OMW treatment are essentially based either on conventional chemical-physical, biological and thermal processes, or on membrane processes. With respect to conventional methods, membrane processes allow to separate different species without the use of chemicals or heat. This work deals with the use of the integrated pressure-driven membrane processes for the treatment of OMW. They consist of a first stage (microfiltration, MF) in which a porous multichannel ceramic membrane retains suspended materials and produces a clarified permeate for a second stage (reverse osmosis, RO), in order to separate (and concentrate) dissolved substances from water. Laboratory scale experiments with different small flat sheet RO membranes were first carried out in order to select the most appropriate one for the successive bench scale tests with a spiral wound module having a large membrane surface. The aim of this test was to concentrate the dissolved substances and to produce water with low salinity, chemical oxygen demand (COD), and reduced phytotoxicity due to a low content of phenolic compounds. The trend of the permeate flux and membrane retention as a function of the volume concentration ratio was investigated. The influence of OMW origin and its aging on the membrane performance was also studied.

Towards Upscaling of La5.5WO11.25-δ Manufacture for Plasma Spraying-Thin Film Coated Hydrogen Permeable Membranes.

Lanthanum tungstate (La6WO12) is a promising material for the development of hydrogen separation membranes, proton ceramic electrolyzer cells and protonic ceramic fuel cells due to its interesting transport properties and stability under different operation conditions. In order to improve the hydrogen transport through the La6WO12 membranes, thin membranes should be manufactured. This work is based on the industrial production of La5.5WO11.25-δ (LWO) powder by spray drying and the manufacturing of thin membranes by low-pressure plasma spraying (LPPS-TF) technique. LPPS-TF allows the production of dense thin films of high quality in an industrial scale. The powders produced by spray drying were morphological and electrochemically characterized. Hydrogen permeation fluxes of a membrane manufactured with these powders were evaluated and fluxes are similar to those reported previously for LWO powder produced in the lab scale. Finally, the transport properties of LWO thin films deposited on Al2O3 indicate that LPPS-TF produces high-quality LWO films with potential for integration in different applications.

The Maximal Pore Size of Hydrophobic Microporous Membranes Does Not Fully Characterize the Resistance to Plasma Breakthrough of Membrane Devices for Extracorporeal Blood Oxygenation.

Extracorporeal membrane oxygenation (ECMO) in blood-outside devices equipped with hydrophobic membranes has become routine treatment of respiratory or cardiac failure. In spite of membrane hydrophobicity, significant amounts of plasma water may form in the gas compartment during treatment, an event termed plasma water breakthrough. When this occurs, plasma water occludes some gas pathways and ultimately cripples the oxygenator gas exchange capacity requiring its substitution. This causes patient hemodilution and increases the activation of the patient's immune system. On these grounds, the resistance to plasma water breakthrough is regarded as an important feature of ECMO devices. Many possible events may explain the occurrence of plasma breakthrough. In spite of this, the resistance to plasma breakthrough of ECMO devices is commercially characterized only with respect to the membrane maximal pore size, evaluated by the bubble pressure method or by SEM analysis of membrane surfaces. The discrepancy between the complexity of the events causing plasma breakthrough in ECMO devices (hence determining their resistance to plasma breakthrough), and that claimed commercially has caused legal suits on the occasion of the purchase of large stocks of ECMO devices by large hospitals or regional institutions. The main aim of this study was to identify some factors that contribute to determining the resistance to plasma breakthrough of ECMO devices, as a means to minimize litigations triggered by an improper definition of the requirements of a clinically efficient ECMO device. The results obtained show that: membrane resistance to breakthrough should be related to the size of the pores inside the membrane wall rather than at its surface; membranes with similar nominal maximal pore size may exhibit pores with significantly different size distribution; membrane pore size distribution rather than the maximal pore size determines membrane resistance to breakthrough; the presence of surfactants in the patient's blood (e.g., lipids, alcohol, etc.) may significantly modify the intrinsic membrane resistance to breakthrough, more so the higher the surfactant concentration. We conclude that the requirements of ECMO devices in terms of resistance to plasma breakthrough ought to account for all these factors and not rely only on membrane maximal pore size.

Electron microscopy characterization of airborne micro- and nanoparticulate matter.

The aim of this work was to offer a state-of-the-art critical survey for characterizing airborne nano- and microparticles by means of electron microscopy (EM) techniques and to highlight advantages and limits of different possible operation modes. Procedures of collection and sample preparation are revisited and improved to analyse airborne particles deposited on filtering membranes by using various sampling methods. Three kinds of electron microscopes are used to this end: scanning electron microscope (SEM), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Following and extending previous studies, we optimized procedures by varying both the sample collection/preparation and the operational parameters of the microscopes. In particular, we diversified the sampling methods applied, using ad hoc filters as well as common filters for standard gravimetric measures. This approach enabled us to achieve a simple and clean procedure allowing direct SEM or TEM observation of the collected particulate matter.