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The identification of the most competent embryos for transfer to the uterus constitutes the main challenge of in vitro fertilization (IVF). We established a metabolomic-based approach by applying Fourier transform infrared (FTIR) spectroscopy on 130 samples of 3-day embryo culture supernatants from 26 embryos that implanted and 104 embryos that failed. On examining the internal structure of the data by unsupervised multivariate analysis, we found that the supernatant spectra of nonimplanted embryos constituted a highly heterogeneous group. Whereas ∼40% of these supernatants were spectroscopically indistinguishable from those of successfully implanted embryos, ∼60% exhibited diverse, heterogeneous metabolic fingerprints. This observation proved to be the direct result of pregnancy's multifactorial nature, involving both intrinsic embryonic traits and external characteristics. Our data analysis strategy thus involved one-class modelling techniques employing soft independent modelling of class analogy that identified deviant fingerprints as unsuitable for implantation. From these findings, we could develop a noninvasive Fourier-transform-infrared-spectroscopy–based approach that represents a shift in the fundamental paradigm for data modelling applied in assisted-fertilization technologies. [ABSTRACT FROM AUTHOR]

Biofilms are microbial communities encased in a protective matrix composed of exopolymeric substances including exopolysaccharides, proteins, lipids, and extracellular DNA. Biofilms cause undesirable effects such as biofouling, equipment damage, prostheses colonization, and disease. Biofilms are also more resilient than free-living cells to regular decontamination methods and therefore, alternative methods are needed to eradicate them. The use of non-thermal atmospheric pressure plasmas is a good alternative as plasmas contain reactive species, free radicals, and UV photons well-known for their decontamination potential against free microorganisms. Pseudomonas aeruginosa biofilms colonize catheters, indwelling devices, and prostheses. Plasma effects on cell viability have been previously documented for P. aeruginosa biofilms. Nonetheless, the effect of plasma on the biofilm matrix has received less attention and there is little evidence regarding the changes the matrix undergoes. The aim of this work was to study the effect plasma exerts mostly on the P. aeruginosa biofilm matrix and to expand the existing knowledge about its effect on sessile cells in order to achieve a better understanding of the mechanism/s underlying plasma-mediated biofilm inactivation. We report a reduction in the amount of the biofilm matrix, the loss of its tridimensional structure, and morphological changes in sessile cells at long exposure times. We show chemical and structural changes on the biofilm matrix (mostly on carbohydrates and eDNA) and cells (mostly on proteins and lipids) that are more profound with longer plasma exposure times. We also demonstrate the presence of lipid oxidation products confirming cell membrane lipid peroxidation as plasma exposure time increases. To our knowledge this is the first report providing detailed evidence of the variety of chemical and structural changes that occur mostly on the biofilm matrix and sessile cells as a consequence of the plasma treatment. Based on our results, we propose a comprehensive model explaining plasma-mediated biofilm inactivation. [ABSTRACT FROM AUTHOR]

Highlights • NF, RO and MD comparison for the treatment of As-contaminated waters. • NF and RO performance depending on the water quality and As content. • Pre-oxidation of As(III) needed for both NF and RO, but not for MD. • Wider range of As content, lower fluxes, higher rejections and energy demand for MD. • Similar energy request for MD, NF and RO if thermal/renewable energy is available. Abstract The presence of arsenic in water beyond the admitted limits is becoming an important concern for many Countries. Methods usually employed for the arsenic removal from water are based on coagulation followed by filtration, ion-exchange, adsorption. Drawbacks like the use of chemicals and the production of sludges (in case of coagulation) have, however, to be mentioned. Membrane operations, based on the features of membrane materials involved in the separation, do not need chemicals and are easy to scale-up, due to their modularity. In this contribution, the potential of membrane operations for the treatment of arsenic-polluted water is presented and discussed. In particular, two classes of membrane operations are illustrated and compared, the pressure-driven, like Nanofiltration (NF) and Reverse Osmosis (RO) and the thermally-driven ones, like Membrane Distillation (MD). [ABSTRACT FROM AUTHOR]

Graphical abstract SENTENCE OF TEXT HIGHLIGHTING THE NOVELTY OF THE WORK: Polymeric membranes offer great potential for aromatherapy applications, allowing the separation of some bergamot essential oil from the starting phytocomplex. Highlights • Use of membranes as alternative technology for concentrating and isolating BEO volatile compounds. • Three polymeric lab-made and two commercials dense membranes were tested. • HS-SPME coupled with GC/MS was employed for analyzing BEO volatile components in feed and permeate. • The use of a membrane prototype allows separating some BEO components from starting phytocomplex. • The PSU and cellulose membranes selectively concentrated BEO volatile compounds. Abstract Aromatherapy is a form of complementary and alternative therapy that uses essential oils extracted from different organs of aromatic plants. BEO, extracted from Citrus bergamia Risso et Poiteau (Rutaceae family, genus Citrus) fruit, represents one of the most used aromatherapy oil in the industrialized countries. Biological effects of BEO are due to a synergistic action of the components present in the phytocomplex but it is not yet known which components are crucial for the biological activity. In this work three polymeric lab-made and two commercials dense membranes were tested for concentrating and isolating BEO volatile compounds. Lab-made membranes, composed of poly PVDF-HFP, PSU and SBS, were prepared via EIPS. Commercial investigated membranes were made of cellulose and polyamide. The membranes have been also characterized to determine morphological and surface properties. Volatile aroma compounds were isolated from BEO by means of a vapor permeation system. For this purpose, a membrane prototype which allowed to vaporize BEO and to separate specific components by their passage through the membrane, was developed. HS-SPME coupled with GC/MS was employed for the analysis of BEO volatile components both in feed and permeate. Hand-made PSU and commercial cellulose membranes were able to reject a greater number of volatile components than the other tested membranes. In particular, all cyclic and acyclic oxygenated monoterpenes (linalool, linalyl acetate, terpinen-4-ol, α-terpineol) were not detected in the permeate. The results showed that with the dense PSU membrane limonene (53.121%) and p -cymene (2.070%) contents were lower than the relative contents registered with the commercial cellulose membrane (63.440% and 3.325%, respectively), indicating a higher membrane selectivity of M3 towards these components. Contrarily, the rejection of both α- and β-pinene was higher when cellulose membrane was used (6.401% and 22.740%, respectively) in comparison to that observed for the PSU lab-made membrane (9.801% and 29.535%), respectively. [ABSTRACT FROM AUTHOR]

Innovative hydrophobic coated membranes have been prepared and characterised in Direct Contact Membrane Distillation (DCMD) for potential water treatment applications. A UV-curable perfluoropolyether (PFPE) hydrophobic compound (Fluorolink® AD 1700) was used as coating material to tailor the surface of commercial microfiltration hydrophilic polyamide (PA) membranes with different pore sizes. The coated membranes consisted of a top thin hydrophobic porous layer overlying the hydrophilic commercial membrane support. Produced membranes were fully characterised in terms of surface and cross-section morphology, water contact angle, porosity, pore size and liquid entry pressure. The innovative coated hydrophobic membranes were tested in DCMD configuration, using deionized water and salty solution 0.6 M (NaCl) as feed. In particular, the effect of the coating concentration on the permeate fluxes was investigated for different hydrophilic pore size commercial membranes (0.1–0.22–0.45 μm). The measured permeate fluxes ranged between 4.56–22.81 kg/m 2 h at different feed temperatures (40–50–60 °C) keeping constant the permeate temperature at 14 °C, for deionized water, whereas an average value of 11 kg/m 2 h, at 50 °C was found in case of the salty solution. [ABSTRACT FROM AUTHOR]

Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs) look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III) and As(V) from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM) configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s) plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM) systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration. [ABSTRACT FROM AUTHOR]

An innovative hydrophilic and anti-fouling coating material for application in membrane technology for wastewater treatment has been developed by polymerization of a polymerizable bicontinuous microemulsion (PBM) and used for surface modification of a commercial flat polyethersulfone (PES) membrane. The novel nanostructured coating has been produced using acryloyloxyundecyltriethylammonium bromide (AUTEAB) as a co-polymerizable surfactant, obtained through a synthetic method characterized by a lower cost and a higher reproducibility compared to other known polymerizable surfactants. The novel composite membranes have been characterized and compared with the uncoated PES membranes. Coated membranes resulted in a smoother surface and a higher hydrophilicity with respect to the uncoated ones, and showed a particular nano-size channel-like morphology making them highly resistant to the fouling phenomenon. The covalent anchorage of the surfactant on the membrane surface ensured the embedment of the molecule in the polymeric matrix avoiding its leaching and also leading the coated membranes to have significant antimicrobial activity, which is very important for reducing the biofouling phenomenon. All these aspects make the tailored coating material an ideal and efficient coating for modifications of commercial membrane surfaces, to be used in membrane processes in wastewater treatment. [ABSTRACT FROM AUTHOR]

This work focuses on the preparation of porous mixed matrix membranes (MMMs) by non-solvent induced phase separation (NIPS) using poly(vinylidenefluoride) (PVDF) as polymer and nano-sized silicalite-1 (S-1) and Ti-silicalite-1 (TS-1) seeds of MFI zeolite structure as inorganic fillers. These MMMs have been used as VOCs adsorbers. Different zeolite seed concentrations (up to 22 wt.%) were homogeneously dispersed into the polymeric matrix to evaluate the influence of the amount of zeolites on the membrane characteristics. In all cases, asymmetric porous membranes, made up of two layers were obtained: the bottom side exhibited spherulitic structure; whereas, at the top side, a smooth layer was observed. With respect to the neat PVDF membranes, the hydrophobic character was found to be improved by the zeolite addition; in particular S-1 nano-seeds. The mechanical properties of the membranes were reduced by the addition of the filler, although the mechanical resistance of the MMMs was still sufficiently preserved. Experiments of hexane adsorption were carried out in order to evaluate the performance of the adsorbers in Volatile Organic Compounds (VOCs) removal. The as-prepared composite porous membranes revealed high adsorption capacity, confirming their potential as adsorbers for removing VOCs traces from waste air environment. [ABSTRACT FROM AUTHOR]

This critical review accomplished two main tasks: first, the article provides scope for identifying the most common conceptions of moral competence in the scientific literature, as well as the different ways to measure this type of competence. Having moral judgment is the most popular element of moral competence, but the literature introduces many other elements. The review also shows there is a plethora of ways to measure moral competence, either in standardized tests providing scores or other non-standardized tests. As a second task, the article reflects critically on the general use of the idea of moral competence. Results suggest that this idea functions as what philosopher Bernard Williams would have called a thin ethical concept. Thin concepts are not problematic in and of themselves if they are used as linguistic shorthand, however, there may be shortcomings in the literature on moral competence because the idea is not rooted in more substantive views or theories in a way that is both clear and coherent. [ABSTRACT FROM AUTHOR]

Solvents are used in every chemical process and affect its overall safety, environmental, and economic impact. Membrane processes have attracted increasing interest as sustainable alternatives to traditional technologies, being characterized by reduced energy consumption and use of chemicals. However, the most important membrane preparation techniques are often based on the use of toxic solvents, which reduces the benefit to the environment. Due to the influence of solvent properties such as viscosity, dielectric constant, polarity, and boiling point on the final features and the indispensable prerequisite of dissolving the selected polymer (at room or high temperature, depending on the technique), one of the most difficult but most interesting challenges for membrane scientists is replacing these solvents, such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), N-methyl-2-pyrrolidone (NMP), and tetrahydrofuran (THF), with safer alternatives. In this review, the most relevant steps towards the use of non-toxic solvents in membrane preparation are reported, focusing particular attention on the nonsolvent induced and temperature induced phase separation (NIPS and TIPS) techniques. Supercritical CO2 (ScCO2) and ionic liquids (ILs) are promising examples of benign solvents, and their use in membrane preparation will also be described. The total replacement of toxic diluents with greener alternatives still remains at the beginning stages. However, in several cases, membranes prepared using less/non-toxic solvents achieved performance comparable to those produced with classical toxic solvents. This review offers valid support for membrane scientists who wish to reduce the environmental impact of solvent use and increase membrane processes sustainability. [ABSTRACT FROM AUTHOR]

Abstract: Poly(vinylidene fluoride) microporous hydrophobic hollow fibers were prepared using N-methyl pyrrolidone (NMP) as solvent, and water and low molecular weight poly(vinyl pyrrolidone) (PVP K-17) as pore forming additives. The effect of selected spinning parameters, i.e. composition and flow rate of the inner coagulant (bore fluid), on fiber properties was carefully investigated, keeping constant all the other parameters (composition and temperature of the polymeric dope, spinning rate, outer coagulant composition and temperature). It was found that fiber properties, in particular thickness and porosity, are strongly influenced by the composition and flow rate of the bore fluid. Fiber thickness decreases as bore fluid flow rate increases, as a consequence of enlargement of fiber inner diameter. While fiber porosity, expressed as void fraction, decreases when the liquid/liquid demixing rate decreases during coagulation, due to the reduction of macrovoids. The produced hollow fibers were tested using a vacuum membrane distillation (VMD) setup, both feeding double distilled water and synthetic seawater. The fibers produced reached average transmembrane water vapor fluxes as high as 19.50 (pure water) and 14.46kg/m2 h (synthetic seawater), coupled with solute separation factors of about 99.99%. By analyzing the relationship between the fiber VMD performance, morphology and properties, it has been confirmed that VMD flux has strong dependence on porosity, which influences both the space available for evaporation and the thermal insulation during the process. This systematic study allowed us to show how fiber properties can be tailored by carefully acting on spinning parameters, in order to obtain high VMD performance both in terms of flux and salt rejection. [Copyright &y& Elsevier]

Encapsulation is a promising technology to carry natural active substances, preventing their loss and maintaining their stability until use. Beads of chitosan-containing propolis have been prepared using a mono-pore filter device, which permits the encapsulation of natural polyphenols avoiding heat treatments, high shear rates and the use of toxic solvents. Beads proved to be active against Bacillis cereus, Escherichia coli, Listeria innocua, Pseudomonas fluorescens, Yarrovia lipolytica and three moulds strains; the highest effect was found against Staphylococcus aureus ( MIC 0.8 mg beads mL−1). Results in liquid cultures of S. aureus evidenced that beads were able to release the flavonoids from propolis: the diffusion of the active compounds is a key factor in the exploitation of the microbial activity. The obtained chitosan-propolis beads represent an example of natural antimicrobial delivery system that could be used to prevent the growth of pathogenic/spoilage bacteria in food applications. [ABSTRACT FROM AUTHOR]

Abstract: In this work, different PVDF grades were used for producing hollow fibers for application in seawater desalination by membrane distillation (MD). In particular, PVDF Solef® homopolymers, with increasing molecular weight and different crystallinity, were used, also in blend, for preparing polymeric dopes. The effect of PVDF molecular weight on the dope viscosity was investigated. Then, a group of six polymeric dopes, having the same additive composition and the same viscosity (about 7000 mPas), but containing different PVDF types was selected. Spinning experiments were carried out under the same conditions to highlight the effect of PVDF type on the produced hollow fibers’ morphology and properties. It was evidenced that polymer concentration plays a major role in determining the final membrane morphology; in particular, the formation of macrovoids is more affected by polymer concentration than dope viscosity. Fibers’ mechanical properties, porosity and pore size were found to be also strongly affected by polymer concentration. Finally, the produced hollow fibers were tested in a membrane distillation unit working under vacuum (VMD). Tests were carried out both feeding pure water and synthetic seawater. It was found that VMD performance, both in terms of flux (J) and solute separation factor (α), being connected to fibers’ morphology and porosity, is also clearly dependent on polymer concentration. [Copyright &y& Elsevier]

Abstract: The membrane process concept coupled with phase inversion technique has been successfully applied for the first time for the preparation of ionic liquid (IL) encapsulated microspheres using polyetheretherketone with card group (PEEKWC), trihexyl(tetradecyl)phosphonium chloride[CYPHOS IL 101] in N,N-dimethylformamide (DMF) as dispersing phase and dodecane, ethanol and water as continuous phases. The technique yields porous, spongy, spheres with smooth surface and diameter around 1000μm, with morphology and chemical composition strongly affected by preparative conditions. IL loading capacity and subsequent surface topography has been investigated using optical microscopy, FT-IR, SEM, EDX, TGA and SDT. [Copyright &y& Elsevier]

Abstract: In this work, polymeric membranes have been prepared by thermal induced phase inversion (TIPS) using Ethylene–Chlorotrifluoroethylene copolymer (ECTFE). N-methyl pyrrolidone (NMP) has been used as solvent. Moreover, four different additives, i.e. glycerol triacetate (GTA), triethyl citrate (CTF), dibutyl itaconate (DBI) and diethyl adipate (DEA), have been tested in order to improve polymer processability. The microstructure of the obtained membranes has been analyzed by scanning electron microscopy (SEM). In all cases, asymmetric membranes, made up of two layers have been observed: the bottom side consists of spherulitic structures, which develop as a consequence of polymer crystallization; at the top side, a fully dense skin, having variable thickness, can be observed. Membranes show excellent resistance to most aggressive organic solvents, such as: Dimethyl Formamide (DMF), Dimethyl Acetamide (DMA), N-methyl pyrrolidone (NMP), Tetrahydrofuran (THF), toluene, Chloroform and Acetone. For each solvent, solvent uptake tests of 72h have been performed. Besides, solvent uptake tests have been carried out using organic solvent/water and organic/organic mixtures. The obtained results suggest that the prepared ECTFE dense membranes are very promising candidates for organic solvents pervaporation but also for nanofiltration. Preliminary pervaporation (PV) tests on aqueous solutions of toluene (200–250ppm) have been also carried out. [Copyright &y& Elsevier]

Abstract: The pervaporation properties of poly lactic acid (PLA), a natural source polymer, were studied in a polar/non-polar case study. PLA/PVP (poly vinyl pyrrolidone) blend membranes were prepared containing different PVP contents and evaluated in ethanol/ethyl tert-butyl ether azeotropic separation. The swelling and mechanical properties of the membranes were investigated. SEM cross-sectional images showed a porous structure at higher PVP concentrations. The degree of swelling as well as the permeation flux (0.05–1.36kg/m2 h) gradually increased when the PVP amount increased to 21wt%. On the other hand, the EtOH separation factor initially raised to 16 using 3wt% PVP and then decreased to 3 using 21wt% PVP. The continuously decreasing water contact angle from 74° in PLA to 54° confirmed higher hydrophilicity and EtOH affinity at higher PVP contents. However, the more porous morphology and the plasticization effect resulted in selectivity decrease. This was also in agreement with the observed mechanical behavior of the blends. At higher EtOH concentrations and PVP contents, the elastic modulus of the membranes decreased, contrary to the membrane elongation. [Copyright &y& Elsevier]

Abstract: Modified poly(ether ether ketone) (PEEKWC) dense membranes were prepared using chloroform as the evaporating solvent. Pervaporation of methanol (MeOH) and methyl tert-butyl ether (MTBE) mixtures were carried out at different feed concentrations, flow rates and temperatures. The swelling and mechanical properties of the membranes were studied at different MeOH concentrations. These MeOH selective membranes were mechanically strong for PV tests. However, their strength decreased in feed mixture to some extent particularly in contact with high concentrations of MeOH. The observed high separation factor of more than 250 at 1wt% MeOH dropped to an ultimate value of 4–6 at around 20–50wt% MeOH. Meanwhile, total permeation flux increased tenfold continuously from 0.015kg/m2 h to 0.113kg/m2 h at 87.2wt% MeOH in feed. Increasing the feed flow rate had a positive effect on both the separation factor and the permeation flux due to the elimination of concentration and temperature polarization. Increasing the feed temperature improved the permeation rate as well. However, the separation factors slightly decreased at higher temperatures. The observed effects of feed temperature on the PV results are caused by increasing the thermal motions of polymer chains and permeating molecules at higher temperatures. [Copyright &y& Elsevier]

Abstract: Modified poly(ether ether ketone) (PEEKWC) membranes with different poly(vinyl pyrrolidone) (PVP) content were used to separate ethanol/cyclohexane (EtOH/CHx) azeotropic mixture in a pervaporation lab scale apparatus. Eight blends were prepared with the PVP weight percent up to 24%. Several characterization tests were carried out to investigate mechanical, morphological and operational properties of the membranes. These tests include FTIR-ATR, tensile strength, and water contact angle measurements. Furthermore, swelling and pervaporation tests are reported. All the membranes were EtOH selective. The highest separation factor was observed at 21wt% of PVP. Permeation total flux was continuously increased from 3.75×10−3 to 14.81×10−3 kg/m2 h as the PVP content increased from 0 to 24wt%. The structure of the blends changed to a more porous form at higher PVP percents as shown in the SEM images, resulting in higher fluxes. Furthermore, it increased the tendency of EtOH uptake which caused the separation factor to increase simultaneously. Swelling results at different concentrations confirmed the same affinity to EtOH with respect to the PVP amount. As the result of the mechanical tests, Young''s modulus and maximum stress values decreased in the contrary of elongation of the membranes at higher PVP contents and EtOH concentrations. Since EtOH molecules compared to CHx molecules have higher interactions with the polymer chains, the mechanical strength of the membranes is expected to decline at higher EtOH concentrations, particularly at higher PVP amounts. [Copyright &y& Elsevier]

Abstract: Microporous hydrophobic poly(vinylidene fluoride) (PVDF) hollow fibres were prepared by the dry–wet spinning technique. N,N-Dimethylformamide (DMF) was used as solvent, while water and poly(vinyl pyrrolidone) (PVP) were used as pore forming additives. Mixtures of DMF or ethanol in water were employed as bore fluids. The influence of different parameters on the fibres characteristics was explored. Particular attention was focused on the PVP concentration and on the composition of the bore fluid. The obtained fibres exhibit good structure, excellent mechanical properties, high porosity (up to 80%) and an average pore size ranging from 0.12 to 0.27μm. Fibres were tested in vacuum membrane distillation (VMD) configuration, using distilled water as feed. The effect of membrane properties on the water vapor fluxes was investigated. For the prepared membranes, the measured fluxes ranged between 3.5 and 18kg/m2 h at 50°C and 20mbar vacuum pressure. Some selected fibres were assessed for long term stability. Constant performances were observed up to 2 months. Furthermore, preliminary VMD tests on salty water were also performed, in order to verify fibres suitability for seawater desalination. [ABSTRACT FROM AUTHOR]

Abstract: Poly(vinyl pyrrolidone) (PVP) was used as an additive to modify the structure and the physical–chemical properties of poly(lactic acid) (PLA) membranes. The membranes with different PVP contents up to 21.33wt% were employed for pervaporation separation of ethanol/cyclohexane (EtOH/CHx) azeotropic mixture. Several characterization tests were carried out on the membranes including contact angle measurements, mechanical properties before and after immersion in solvent mixtures of different compositions, swelling properties, SEM and FTIR-ATR. The membranes were able to selectively separate EtOH from the feed. The fluxes were continuously increased at higher PVP contents from 0.02 to 0.05kg/(m2 h) due to the higher affinity to EtOH, together with the more porous structure obtained. However, this will cause the separation factor trend to level off at around 120. This behavior was expected since the addition of PVP made the membranes more hydrophilic, decreasing the water contact angle from 74° in pure PLA to 54° with the maximum studied PVP content (21.33wt%). Furthermore, swelling experiments confirmed the same affinity to EtOH at higher PVP contents. The values of Young''s modulus decreased, contrary to the membrane elongation, at higher EtOH concentrations in comparison with the untreated membranes. The same trends exist for the blend membranes with higher amount of PVP. [Copyright &y& Elsevier]

Abstract: Laboratory-made silicalite filled PDMS membranes were tested by means of concentration and temperature influence on the membrane performance in removal of ethanol from ethanol/water mixtures. This allowed studying the applicability of solution-diffusion model in the transport mechanism description. Experiments were performed by varying the ethanol concentration in the feed and temperature. Two types of fillers were incorporated into the PDMS network: commercial zeolite silicalite (CBV 3002) and laboratory-made colloidal silicalite-1. Obtained results were then compared with data gathered for unfilled PDMS membranes to examine the effect of fillers incorporation. Moreover, the comparison with novel block co-polymer based porous and dense SBS membranes was done. It was found that the solution-diffusion model was a good representation of ethanol transport through both filled and unfilled PDMS membranes, whereas the water flux did not obey this model due to the swelling effects. Incorporation of the fillers increased membrane stability and improved the selectivity. Performance of the SBS membranes characterized by a dense structure was found to be similar to the performance of filled PDMS membranes. [Copyright &y& Elsevier]

Abstract: The processing of kiwifruit for obtaining products with a higher sensory quality, to be used in the food industry, is associated with the use of techniques which can limit the physical and chemical losses of aroma compounds. Pervaporation (PV) represents an alternative to the techniques based on distillation/evaporation or partial condensation to concentrate the aroma compounds preserving the molecule integrity (mild operational conditions used), having a high selectivity towards the organic volatile compounds, and respecting also the environment. The most representative volatile compounds of the kiwifruit aroma was chosen for evaluating the pervaporation process. SPME‐GC/ion trap mass spectrometry method was exploited to determine the amounts of these compounds. The approach was based on chemical ionization acquisition with isobutane as reagent gas and 1‐heptanol and (Z)‐3‐hexen‐yl acetate as internal standards. In these conditions, the calibration curves were satisfactory as demonstrated by the R 2 values of the straight lines (0.9937–0.9999). A kiwifruit fresh juice was processed by pervaporation through the composite commercial membrane (GFT1070) and the one self‐prepared, made of styrene butadiene co‐styrene (SBS), at three different feed temperatures. Marked effects for both membranes were observed in the total and partial fluxes of aroma compounds as the temperature was increased. The studied aroma compounds were differently affected by the temperature changes during PV process, with the result of a change in concentration in the permeate of the aroma compounds recovered. [Copyright &y& Elsevier]

Abstract: Arsenic contamination of surface and groundwater is a worldwide problem in a large number of Countries (Bangladesh, Argentina, Italy, USA, New Zealand, etc.). In many contaminated areas a continuous investigation of the available arsenic removal technologies is essential to develop economical and effective methods for removing arsenic in order to meet the new Maximum Contaminant Level (MCL) standard (10μg/l) recommended by the World Health Organization (WHO). In this work the removal of pentavalent arsenic from synthetic water was studied on laboratory scale by using two commercial nanofiltration (NF) spiral-wound membrane modules (N30F by Microdyn-Nadir and NF90 by Dow Chemical). The influence of main operating parameters such as feed concentration, pH, pressure and temperature on the As rejection and permeate flux of both membranes, was investigated. An increase of pH and a decrease of operating temperature and As feed concentration led to higher As removal for both membranes, whereas higher transmembrane pressure (TMP) values slightly reduced the removal achievable with the N30F membrane. In both cases, the permeate flux increased with temperature and pressure and reached its maximum value at a pH of around 8. Among the parameters affecting the As rejection, feed concentration plays a key role for the production of a permeate stream respecting the limits imposed by WHO. [Copyright &y& Elsevier]

In this work, polyvinilydene fluoride (PVDF) microcapsules were prepared by using combined emulsion and phase inversion techniques. With this method, microcapsules with different diameters and porosities have been obtained by just controlling the diameter of the membrane used during the preparation. Using a PVDF solution containing the oxidation catalyst ammonium molybdate (20 wt %), catalytic polymeric microcapsules with diameters ranging from 600 to 1200 μm have been obtained. Characterization of catalytic microcapsules by means of SEM, BSE, and EDX analyses showed a uniform ammonium molybdate dispersion in the polymeric matrix. Catalytic microcapsules have been tested in the oxidation of aromatic primary alcohols to corresponding aldehydes. In the range 600−1200 μm, the microcapsule diameter influences the formation of oxidation products: in particular, microcapsule diameters >900 μm slightly diminish the formation of aldehyde due to a beginning diffusion limitation. An interesting structure−reactivity behavior, induced by the interaction between the polymeric membrane and the substituted aromatic alcohol, has been observed. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we report on the preparation, characterization and use of new catalytic polymeric microcapsules for the selective oxidation of benzyl alcohols to benzaldehydes. The catalyst, ammonium molybdate tetrahydrate, was entrapped inside modified polyetheretherketone (PEEKWC) polymeric microcapsules during their preparation. Catalytic activity of the new PEEKWC microcapsules has been evaluated in the oxidation of substituted benzyl alcohols to benzaldehydes using hydrogen peroxide as oxidant. EDX analysis of the catalytic microcapsules showed a satisfactorily catalyst distribution on the shell and on the inner core. Proof of successful entrapment of catalyst inside polymeric matrix during the preparation was given by the different colorimetric reactions between the catalytic PEEKWC microcapsules and the oxidant (hydrogen peroxide). An interesting structure-reactivity behaviour, that may indeed be induced by the interaction between the polymeric membrane and the substrate, has been observed. PEEKWC catalytic microcapsules were stable under oxidation conditions and can be recycled without a loss of activity. [Copyright &y& Elsevier]

Abstract: Novel polyvinylidene fluoride (PVDF) porous microcapsule membranes were successfully prepared with non-solvent induced phase inversion method for the immobilization of catalyst ammonium molybdate tetrahydrate ((NH4)6Mo7O24·4H2O). The chemical–physical analysis of the new PVDF catalytic microcapsules was carried out by means of SEM, EDX, IR, DSC and XRD techniques. Catalytic activity of the PVDF catalytic microcapsules has been evaluated in the oxidation of benzyl alcohol to benzaldehyde in solvent free conditions. The polymeric microcapsules “keep in contact” the two phases: the organic phase, containing the substrate and the product, and the aqueous phase with the oxidant, H2O2. In literature, ((NH4)6Mo7O24·4H2O) was reported to be effective in the oxidation of alcohols with H2O2 in combination with a phase transfer catalyst in chlorinated solvents. The effect of reaction temperature, substrate:oxidant ratio, swelling of polymeric microcapsules on the reaction progress was investigated. PVDF catalytic microcapsules have given proof of their complete stability under oxidation conditions and their good recycle. [Copyright &y& Elsevier]

Abstract: In this study, the performance of a hydrophobic nanofiltration membrane (SolSep 3360) for treating alcoholic solutions by pervaporation is investigated and compared to a conventional pervaporation membrane (PV 1070, Sulzer Chemtech and Pervatech PDMS). Both binary ethanol/water mixtures and common multicomponent mixtures (alcoholic beverages) are examined. The experiments were performed at feed ethanol concentrations up to 50vol% and at temperatures up to 45°C. The effects of feed ethanol content and temperature were studied in terms of: (1) fluxes and permeances of individual components, and (2) separation factor, enrichment factor and selectivity of ethanol to water. Using permeance and selectivity instead of flux and separation/enrichment factor allows the effects on performance evaluation of operating conditions, such as temperature and swelling, to be decoupled. In this way the contribution by nature of the membrane to separation performance can be clarified and quantified. In addition, previous analyses indicate that the aqueous activity coefficient and the saturated vapour pressure play an important role when evaluating the membrane performance in terms of permeance and selectivity. This is confirmed by this study. Furthermore, it was found that multicomponent alcoholic beverages behave in exact the same manner as binary ethanol/water mixtures. Using a nanofiltration membrane for pervaporation purposes is a suitable possibility, because of the higher fluxes and permeances, while remaining a good separation factor and selectivity. The difference between nanofiltration and pervaporation membranes is explained by the influence of swelling, making the membrane more dense, and the different interactions between permeating molecules and the membrane. [Copyright &y& Elsevier]

A novel type of modified polyetheretherketone (PEEKWC) microcapsules was prepared using a procedure which combines membranes with the sol-gel phase inversion technique. An experimental and theoretical study was carried out to explore the fundamental aspects concerning the production of these polymeric capsules. By using a mono-pore polyethylene (PE) film with a pore diameter ranging from 300 to 1400 µm the formation of PEEKWC microcapsules with different morphologies was performed. The capsule morphology, its shape, and size can easily be adjusted with changing parameters such as polymer concentration, solvent, and nonsolvent involved phases. The mean diameter of the obtained microcapsules, with different morphology, ranged from 650 to 2200 µm. The capsules sizes, obtained experimentally were compared with the droplet diameter derived by a balance force analysis along the pore mouth. The theoretical analysis permitted to understand the droplet detachment mechanism, occurring during this process as a function of the membrane and process parameters involved. This study analyzed the different morphology and sizes of the capsules and clarified the mechanism by which the capsules are formed as a function of the parameters involved in the process. [ABSTRACT FROM AUTHOR]

Abstract: Bergamot peel oil is the most valuable essential oil due to its unique fragrance and freshness. The essence finds application in the cosmetic, pharmaceutical and food industries. However, strong limitations have been imposed on its use since bergamot oil contains several coumarins and psoralens which may be photoactive. Qualitative and quantitative analyses with GC–MS were carried out to evaluate the aroma flavour bouquet of the bergamot essential oil obtained by pervaporation (PV). In all PV experiments, made at different ethanol feed concentration and temperature, the bergapten was not detected in the permeate while the aroma components, present in the feed, permeate through the commercial Pervap 1070 membrane. Bergapten is a photoactive component of bergamot essential oil which, in combination with UV radiation, promotes melanogenesis and causes thickening of the stratum corneum. Therefore, PV is a valid alternative for the high quality of essential oil produced without bergapten to the traditional techniques employed in which the bergapten can be removed after an extra-chemical treatment. [Copyright &y& Elsevier]

Abstract: The aim of this study has been to design, on a laboratory scale, an integrated membrane process for the production of concentrated kiwi juice and its aroma recovery. Fresh depectinised kiwifruit juice was clarified by the ultrafiltration (UF) process. The clarified juice was concentrated by osmotic distillation (OD), as an alternative to the traditional vacuum evaporation, up to a total soluble solids (TSS) content higher than 60 °Brix at 25°C. Pervaporation (PV) runs were carried out before and after each membrane unit operation in order to identify the best configuration giving the minimal loss of aroma compounds. For the majority of the aroma compounds detected, the enrichment factor in the permeate of the fresh juice was higher than the clarified and concentrated juice. This result suggests the use of PV for the removal and enrichment of aroma compounds directly from the fresh juice, before any concentration process. The effect of UF and OD on the total antioxidant activity (TAA) and ascorbic acid content of the kiwifruit juice was also evaluated. On the basis of the obtained results, an integrated membrane process scheme for the production of highly nutritional kiwifruit juice has been proposed. [Copyright &y& Elsevier]

Abstract: In the last few years, molecular imprinting technology has entered in different fields of chemistry, biochemistry, biotechnology and medicine. The technique allows us to introduce the molecular memory of the substrate to be recognized in a polymeric material during its preparation. In the present paper, molecularly imprinted enantioselective polymer membranes were prepared by photo-copolymerization of commercial polypropylene membranes with the functional monomer 4-vinylpyridine. The (S)-naproxen was used as a template molecule. Enantioselectivity studies in a dead-end filtration system showed the recognition properties of the imprinted membranes, which exhibited a selective transport of the (S)-enantiomer. [Copyright &y& Elsevier]

The synthesis of novel nanostructured mixed matrix membranes is presented in this contribution. The concept is to embed a liquid in which eventually a carrier can be located, as microscopically small droplets in a polymeric matrix. Preparation of capsules by applying and modifying of traditional encapsulations routes is described in detail and a new method to prepare submicrometer-sized capsules based on interfacial crosslinking or copolymerisation is presented. In the last step, the capsules are embedded in a polymer matrix using a novel film formation technique: the capsules are dispersed in the monomer, which is subsequently polymerised. [Copyright &y& Elsevier]

As a promising technique for multiphase catalytic reactions, the widespread applications of gas–liquid– solid microreactors are still limited by poor durability. Hence, in this work a novel catalytic membrane was synthesised for carrying out the hydrogenation reaction of a bio-oil model compounds. A PEEK-WC membrane was obtained by VIPS/ NIPS technique using a more sustainable solvent (Tamisolve® NxG), with subsequently surface solfanation and doped with Ru. The modified membrane was characterised with different techniques and subsequently tested for the model compounds hydrogenation under mild conditions, achieving 75% furfural conversion and 57.5% furfuryl alcohol selectivity at 85 °C and 18 bar, while only 33% vanillin was converted to vanillin alcohol. The TOF for furfural resulted comparable to that of previously tested catalysts in conventional reactors. The microreactor performed in a stable manner for about 90 h with less than 1% Ru leached out in solution, outperforming previously tested Ru-PES membrane. • Novel synthesis of Ru-PEEK-WC catalytic membrane using sustainable Tamisolve® NxG • Selective (>99%) and rapid (few seconds) hydrogenation of furfural to furfuryl-alcohol under mild conditions • Complete selectivity towards vanillin alcohol at 33% vanillin conversion • Ru-PEEK-WC membrane was able to perform in a stable manner for about 90 h [ABSTRACT FROM AUTHOR]

In this work, a geochemical approach was used as strong-scientific tool for pre-selection of suitable remediation systems to treat Cr-contaminated groundwaters. The geochemical characterization allowed to select Nanofiltration (NF) and Reverse Osmosis (RO) as suitable remediation processes, whereas through a new geochemical modeling, the evolution of water chemistry during the water-rock interaction was also studied. The new reaction path modelling was performed re-evaluating the role of Fe as main oxidant in the system and the analytic concentrations of relevant solutes, including Cr(VI), were reproduced. The spring with the highest Cr(VI) content was treated to lower its concentration below the threshold values. A laboratory-scale set-up was used to carry out both NF and RO experiments. The experiments were conducted on different commercial membranes varying the operating pressures. The results showed high Cr(VI) rejections (around 95%) for all tested membranes, leading to Cr(VI) concentrations below the threshold limits. The high flux, obtained already at lower operating pressures, combined with high selectivity towards Cr(VI) makes NF a favorable remediation option. Image 1 • Investigation of Fe(III) role as potential oxidant of Cr(III) during water-rock interaction. • Geochemical characterization of Cr(VI)-contaminated groundwaters into Italian ophiolitic acquifers. • Use of geochemical approach as tool to improve water remediation systems. • Use of NF/RO membrane processes to decontaminate Cr(VI)-rich groundwaters. [ABSTRACT FROM AUTHOR]

Polymeric membranes, mixed matrix membranes, membrane preparation, membrane characterization, water and wastewater treatment, gas and vapor separation, new solvents in membrane preparation, new polymers in membrane preparation. [Extracted from the article]

Abstract: Capsules of PEEKWC are prepared using a membrane process combined with phase inversion technique. Polymeric droplets were prepared using a mono-pore film in polyethylene with pore diameter ranging from 300 to 1000 μm. The morphology, porosity and shell thickness of the made capsules are modified changing some process parameters such as the polymeric concentration or the non solvent in the coagulation bath. [Copyright &y& Elsevier]

We report that diazepam binding inhibitor (DBI) is a glial messenger mediating crosstalk between satellite glial cells (SGCs) and sensory neurons in the dorsal root ganglion (DRG). DBI is highly expressed in SGCs of mice, rats, and humans, but not in sensory neurons or most other DRG-resident cells. Knockdown of DBI results in a robust mechanical hypersensitivity without major effects on other sensory modalities. In vivo overexpression of DBI in SGCs reduces sensitivity to mechanical stimulation and alleviates mechanical allodynia in neuropathic and inflammatory pain models. We further show that DBI acts as an unconventional agonist and positive allosteric modulator at the neuronal GABAA receptors, particularly strongly affecting those with a high-affinity benzodiazepine binding site. Such receptors are selectively expressed by a subpopulation of mechanosensitive DRG neurons, and these are also more enwrapped with DBI-expressing glia, as compared with other DRG neurons, suggesting a mechanism for a specific effect of DBI on mechanosensation. These findings identified a communication mechanism between peripheral neurons and SGCs. This communication modulates pain signaling and can be targeted therapeutically. [ABSTRACT FROM AUTHOR]

This review focuses on contaminant removal from water using hydrogel-based materials. It highlights the recent results achieved, unresolved problems, and possible developments. Polymer and graphene hydrogels are promising new materials for removing inorganic (e.g., metals and metalloids) and organic (e.g., dyes) trace contaminants from water. They can be prepared as composites with practically any desired conventional or innovative adsorbent, to enhance the removal efficiency. Obtaining a three-dimensional highly effective network is one of the significant features of hydrogels, which confer specific characteristics on them. There are number of benefits of using hydrogels: easy separation and handling, the facility for large-scale application, and the ability to regenerate and reuse the hydrogels. At present, the experiments based on hydrogels for water purification are mostly limited to the laboratory scale and further research needed to move toward large-scale industrial applications. Moreover, the present studies are currently limited to a few types of contaminants, so that further experiments needed for removal of more contaminant types and mixtures of contaminants, considering that in practical situations. All these features are described and discussed in this review, which, to the best of our knowledge, is the first comprehensive review on hydrogel applications for contaminant removal from water. [ABSTRACT FROM AUTHOR]

Conductive polymers, such as polyaniline (PANI), have interesting applications, ranging from flexible electronics, energy storage devices, sensors, antistatic or anticorrosion coatings, etc. However, the full exploitation of conductive polymers still poses a challenge due to their low processability. The use of compatible stabilizers to obtain dispersible and stable colloids is among the possible solutions to overcome such drawbacks. In this work, potato starch was used as a steric stabilizer for the preparation of colloidal polyaniline (emeraldine salt, ES)/starch composites by exploiting the oxidative polymerization of aniline in aqueous solutions with various starch-to-aniline ratios. The polyaniline/starch bio-composites were subjected to structural, spectroscopic, thermal, morphological, and electrochemical analyses. The samples were then tested for their dispersibility/solubility in a range of organic solvents. The results demonstrated the formation of PANI/starch biocomposites with a smaller average size than starch particles, showing improved aqueous dispersion and enhanced solubility in organic solvents. With respect to previously reported PANI-EB (emeraldine base)/starch composites, the novel colloids displayed a lower overall crystallinity, but the conductive nature of PANI-ES enhanced its electrochemical properties, resulting in richer redox chemistry, particularly evident in its oxidation behavior, as observed through cyclic voltammetry. Finally, as proof of the improved processability, the colloids were successfully integrated into a thin polyether sulfone (PES) membrane. [ABSTRACT FROM AUTHOR]

An archaeometric approach was applied to the study of the hoard found in the Samshvilde fortress, one of the richest areas of archaeological artefacts in Caucasian Georgia, since it is representative of the historical events from the Neolithic period until the most recent epochs. In this context, four coins dated back to the 12th–13th centuries AD to the reign of King Giorgi III, Queen Tamar, and King Giorgi IV of Georgia underwent different analytical methods to collect information about the technological production process, the probable forge location, and their conservation state. Optical microscope observations provided details about the decorations, the stylistic aspects, and a preliminary evaluation of the conservation state. Portable X-ray fluorescence and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy analysis revealed a composition consisting almost exclusively of copper with a lower amount of tin, lead, and silver. Moreover, degradation products (copper chlorides and sulphates) and cuprite patina were identified. The metal-supplying areas could be related to the nearby Bolnisi Mining District, and the forge location could coincide with the hoard location in Samshvilde, but further data and analyses are necessary. [ABSTRACT FROM AUTHOR]

• Hollow fiber membranes display important advantages respect to the flat-sheet ones. • The advent of hollow fibers in pervaporation dates back to 90s. • The dehydration of organics by PV using hollow fibers is a very attractive field. • Impressive pervaporation performance can be achieved using different strategies. Pervaporation (PV) has been potentially identified as a candidate in replacing the conventional distillation since it possesses the ability to separate azeotropic solvent mixtures. At a large scale, PV has been mainly involved within hybrid processes for the dehydration of organics toward their purification. Considering that the membrane is the primary separation barrier, "membranologists" are currently seeking for suitable membranes that can be effective for industrial applications. In this regard, due to its minimal fouling and large effective surface area, hollow fiber configuration is recognized as the most advantageous geometry in comparison with flat sheet or tubular modules. Therefore, the goal of this review paper is to provide an outlook on the studies available so far focusing on the use of hollow fiber membranes for the dehydration of organics by PV. By fully reviewing the literature, the main attention is paid to such works that release relevant insights into new membrane concepts and their performance, together with some brief fundamentals of PV technology. The concluding remarks, future trends and recommendations to the new researchers are also given. [ABSTRACT FROM AUTHOR]

Since several decades ago, the application of pervaporation (PV) technology has been mainly aimed at the separation of different types of water-organic, organic-water and organic–organic mixtures, reaching its large-scale application in industry for the dehydration of organics. Today, the versatility and high selectivity toward specific compounds have led its consideration to other types of application such as the assisted chemical and bio-chemical reactions. The focus of this review is to provide a compelling overview on the recent developments of PV combined with chemical and bio-chemical reactions. After a general introduction of PV and its theoretical background, particular emphasis is given to the results obtained in the field for different reactions considered, identifying the key features and weak points of PV in such particular applications. Furthermore, future trends and perspectives are also addressed according to the latest literature reports. [ABSTRACT FROM AUTHOR]

Abstract: The concentration of bergamot peel oils by pervaporation, with and without enzymatic pre-treatment, is studied. The influence of different PV membranes, industrial enzymes and operational parameters on the PV process are also investigated. GC-MS analyses are carried out to evaluate the recovery of the main aroma compounds such as linalool, linalyl acetate and limonene. [Copyright &y& Elsevier]

Polymeric membranes are useful tools for water filtration processes, with their performance strongly dependent on the presence of hydrophilic dopants. In this study, polyaniline (PANI)-capped aluminosilicate (halloysite) nanotubes (HNTs) are dispersed into polyether sulfone (PES), with concentrations ranging from 0.5 to 1.5 wt%, to modify the properties of the PES membrane. Both undoped and HNT-doped PES membranes are investigated in terms of wettability (static and time-dependent contact angle), permeance, mechanical resistance, and morphology (using scanning electron microscopy (SEM)). The higher water permeance observed for the PES membranes incorporating PANI-capped HNTs is, finally, assessed and discussed vis-à-vis the real distribution of HNTs. Indeed, the imaging and characterization in terms of composition, spatial arrangement, and counting of HNTs embedded within the polymeric matrix are demonstrated using non-destructive Micro Particle Induced X-ray Emission (µ-PIXE) and Scanning Transmission Ion Microscopy (STIM) techniques. This approach not only exhibits the unique ability to detect/highlight the distribution of HNTs incorporated throughout the whole thickness of polymer membranes and provide volumetric morphological information consistent with SEM imaging, but also overcomes the limits of the most common analytical techniques exploiting electron probes. These aspects are comprehensively discussed in terms of practical analysis advantages. [ABSTRACT FROM AUTHOR]

Review: 213 refs. [ABSTRACT FROM AUTHOR]

The major challenge for membrane distillation (MD) is the membrane wetting resistance induced by pollutants in the feed solution. The proposed solution for this issue was to fabricate membranes with hydrophobic properties. Hydrophobic electrospun poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membranes were produced for brine treatment using the direct-contact membrane distillation (DCMD) technique. These nanofiber membranes were prepared from three different polymeric solution compositions to study the effect of solvent composition on the electrospinning process. Furthermore, the effect of the polymer concentration was investigated by preparing polymeric solutions with three different polymer percentages: 6, 8, and 10%. All of the nanofiber membranes obtained from electrospinning were post-treated at varying temperatures. The effects of thickness, porosity, pore size, and liquid entry pressure (LEP) were studied. The hydrophobicity was determined using contact angle measurements, which were investigated using optical contact angle goniometry. The crystallinity and thermal properties were studied using DSC and XRD, while the functional groups were studied using FTIR. The morphological study was performed with AMF and described the roughness of nanofiber membranes. Finally, all of the nanofiber membranes had enough of a hydrophobic nature to be used in DCMD. A PVDF membrane filter disc and all nanofiber membranes were applied in DCMD to treat brine water. The resulting water flux and permeate water quality were compared, and it was discovered that all of the produced nanofiber membranes showed good behavior with varying water flux, but the salt rejection was greater than 90%. A membrane prepared from DMF/acetone 5-5 with 10% PVDF-HFP provided the perfect performance, with an average water flux of 44 kg.m−2.h−1 and salt rejection of 99.8%. [ABSTRACT FROM AUTHOR]