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The present study aims to investigate the adsorption behavior of methylene blue (MB) using purified Moroccan clay/alginate beads and optimize the process conditions using Response Surface Methodology (RSM). Composite alginate beads were synthesized via the drop method, and their performance as adsorbents for MB removal was assessed under varying pH levels, adsorbent dosage, and initial MB concentration using the Box-Behnken design. The results revealed that the optimal conditions for achieving 100% MB removal were pH 11.8, adsorbent mass of 4.9 g, and MB concentration of 191 ppm. The adsorption process was well described by the pseudo-second-order kinetic model and Langmuir isotherm model, suggesting that the process involves monolayer adsorption. Moreover, the regenerated adsorbent exhibited satisfactory adsorption performance after five cycles. These findings demonstrate the potential of purified Moroccan clay/alginate beads as an efficient, reusable adsorbent for MB removal from water solutions, contributing to the development of sustainable solutions for dye removal in wastewater treatment applications.

Three different waste animal fats (bone, chicken, and tallow) have been studied to evaluate whether they could be used as bioliquids according to the European Regulation (EC) No.1069/2009. The analyses showed that they contained an unsuitable amount of free fatty acids (FFA) and impurities content (total sediment) if compared with the standards for power generation (set by UNI 6579:2009), with the exception of tallow fat (class C, UNI/TS 11163:2018). A series of physical-chemical processes already applied at industrial scale have been considered to manage the acid value and the impurities content. The FFA esterification was carried out with methanol, comparing two acid catalysts (sulfuric acid or Amberlyst – 15), followed by neutralization of the residual acidity with two different bases (ammonia solution or solid sodium carbonate monohydrate) when necessary. The final purification has been achieved by treatment with powdered activated carbon. In particular, the bone fat was studied as reference material, having the worst initial physical-chemical characteristics. The UNI/TS 11163:2018 standard would allow to classify the bioliquid from bone fat belonging to class B, while the one from chicken would require further degumming and purification processes to reduce the metals, sulfur, and phosphorus content.

ABSTRACTPlasma electrolytic oxidation (PEO) is a relatively new surface treatment that permits to increase the corrosion and wear resistance of metals. One of the peculiarities of the process is the possibility to incorporate into the produced coating the particles suspended in the electrolyte. In this work, micrometric silver particles were added in the PEO coating to innovatively give a fungicidal effect to the samples due to the presence of silver, whose fungicidal effect is well known. PEO coatings were produced on aluminium alloy 7075 using an electrolyte containing sodium silicate and silver particles. The thickness, morphology, composition and corrosion resistance of the obtained coatings were studied. The fungicidal properties were evaluated with contact tests of 2 and 4 h using Candida albicansATCC 10231. Silver particles were homogeneously distributed in the coating and the silver-containing samples were characterised by improved corrosion resistance and high fungicidal activity.

Plasma electrolytic oxidation (PEO) is a relatively new surface treatment that permits to increase the corrosion and wear resistance of metals. One of the peculiarities of the process is the possibility to incorporate into the produced coating the particles suspended in the electrolyte. In this work, micrometric silver particles were added in the PEO coating to innovatively give a fungicidal effect to the samples due to the presence of silver, whose fungicidal effect is well known. PEO coatings were produced on aluminium alloy 7075 using an electrolyte containing sodium silicate and silver particles. The thickness, morphology, composition and corrosion resistance of the obtained coatings were studied. The fungicidal properties were evaluated with contact tests of 2 and 4 h using Candida albicansATCC 10231. Silver particles were homogeneously distributed in the coating and the silver-containing samples were characterised by improved corrosion resistance and high fungicidal activity.

A simple and clean mechanochemical synthesis at room temperature was employed to prepare CuO-Fe2O3-CoCl2(100 nm scale), MoO3-V2O5, CuO-CoCl2, Fe2O3-CoCl2, CuO-V2O5, Cu(CH3COO)2-V2O5, Cu(CH3COO)2-MoO3(1–100 μm scale) 3dmetal based dispersed composites with different ratios of components using simple metal salts/oxides and multiwalled carbon nanotubes (CNT) or graphene oxide (GO) additives (CoCl2-CNT, CoCl2-GO). The thus prepared composite materials were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), field emission gun scanning electron microscopy (FEGSEM), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). XPS analysis revealed no metal redox change upon ball milling treatment, which however promotes metal hydroxylation.

Complex formation between AlIII and various bidentate and potentially tridentate amino acids (Gly, Ser, Thr, Gln, Asn, Glu and Asp) and some model compounds (N-acetylaspartic acid, succinic acid, and 2-sulfanylsuccinic acid) was studied in aqueous solution by pH-potentiometric and multinuclear (1H, 13C and 27Al) NMR techniques. A weak interaction through the carboxylate function was unambiguously detected for all of these ligands. For Asp, however, which contains two carboxylates and a central amino donor, tridentate co-ordination is strongly suggested. Although its steric environment is similar to that of the amino function in Asp, binding of the thiolate sulfur of 2-sulfanylsuccinic acid could not be verified.

Abstract: Nine perfluoroalkyl quaternary ammonium salts containing a perfluorinated tail were synthesized in order to evaluate their properties as additives in protein-based fire-fighting foam concentrates. They were obtained in high yield starting from (perfluoro-n-octyl)methyl oxirane via a two-step reaction scheme. Their structures were identified by Fourier-transform infrared spectroscopy and elemental analysis. Surface tension, interfacial tension, critical micellar concentration, and spreading coefficient of aqueous solutions of the synthesized compounds were first determined. Synthetic perfluoroalkyl quaternary ammonium salts were then added at reduced concentration (0.5 wt.%) to a commercial protein-based fire-fighting foam concentrate and their effects on foam spreading properties were further investigated via five specific laboratory tests: sealing time test, burn back time test, foam expansion test, drain time test, and foam flowing test. Results showed that the perfluoroalkyl quaternary ammonium salts strongly influence surface and extinguishing properties of protein-based fire-fighting foam concentrates, producing stable foams able to spread spontaneously over hydrocarbons and forming aqueous films with enhanced organic-vapor sealing properties.

Nine perfluoroalkyl quaternary ammonium salts containing a perfluorinated tail were synthesized in order to evaluate their properties as additives in protein-based fire-fighting foam concentrates. They were obtained in high yield starting from (perfluoro-n-octyl)methyl oxirane via a two-step reaction scheme. Their structures were identified by Fourier-transform infrared spectroscopy and elemental analysis. Surface tension, interfacial tension, critical micellar concentration, and spreading coefficient of aqueous solutions of the synthesized compounds were first determined. Synthetic perfluoroalkyl quaternary ammonium salts were then added at reduced concentration (0.5 wt.%) to a commercial protein-based fire-fighting foam concentrate and their effects on foam spreading properties were further investigated via five specific laboratory tests: sealing time test, burn back time test, foam expansion test, drain time test, and foam flowing test. Results showed that the perfluoroalkyl quaternary ammonium salts strongly influence surface and extinguishing properties of protein-based fire-fighting foam concentrates, producing stable foams able to spread spontaneously over hydrocarbons and forming aqueous films with enhanced organic-vapor sealing properties.

Summary: Samples of HDPE and PA6 have been melt-processed in the presence of two new phosphazene compounds, CP‐2EPOX and CP‐2OXA together with an ethylene/acrylic acid copolymer. The blends have been prepared in an industrial twin‐screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE‐rich blend in the presence of CP‐2EPOX. This result can be attributed both to a chain extension reaction on EAA and PA6 phases and on compatibilization effect due to the possible formation of EAA‐g‐PA6 copolymers. This latter occurrence is suggested by an improved adhesion between the phases and by an increased turbidity observed in the Molau tests. Between the two compatibilizers, the CP‐2EPOX displays the overall best results, especially for the PE‐based blends.SEM micrograph of the PA6-based binary blend.

Summary:In this paper we highlighted the general situation of metal containing poly(organophosphazenes) and we presented the status of the art in this area in terms of interactions between phosphazene materials and different types of metals. Possible practical utilization of the polymers obtained is also envisaged.

The AlIII‐binding abilities of two aldaric acids, D‐saccharic acid and mucic acid (the neutral form is denoted as H2L), were studied in solution by means of pH potentiometric, 1H and 13C NMR, and ESI‐MS techniques. The most probable conformations and isomeric binding modes of the complexes formed in solution were determined by density functional theory (DFT) calculations. A solid D‐saccharic acid complex K2[{Al(LH−2)(H2O)}2]⋅H2O was isolated and crystallographically characterised. The two alcoholic hydroxy groups α to the terminal COO−groups were found to take part in the coordination, but in different ways. One of them coordinates in a bridging mode. Detailed ESI‐MS and NMR studies proved that the complex retains its structure in solution. However, depending on the ligand and the pH, such complexes may exist in two isomeric forms. DFT calculations on the ion [{Al(LH−2)(H2O)}2]2−revealed that several orbitals participate in stabilizing the dimeric arrangement.

The Al^III-binding abilities of two aldaric acids, D-saccharic acid and mucic acid (the neutral form is denoted as H2L), were studied in solution by means of pH potentiometric, ¹H and ¹³C NMR, and ESI-MS techniques. The most probable conformations and isomeric binding modes of the complexes formed in solution were determined by density functional theory (DFT) calculations. A solid D-saccharic acid complex K2[{Al(LH−2)(H2O)}2]·H2O was isolated and crystallographically characterised. The two alcoholic hydroxy groups α to the terminal COO⁻ groups were found to take part in the coordination, but in different ways. One of them coordinates in a bridging mode. Detailed ESI-MS and NMR studies proved that the complex retains its structure in solution. However, depending on the ligand and the pH, such complexes may exist in two isomeric forms. DFT calculations on the ion [{Al(LH−2)(H2O)}2]²⁻ revealed that several orbitals participate in stabilizing the dimeric arrangement.

The utilization of Cyclophosphazenes as polymer modifiers is reviewed, with particular concern to their exploitation as versatile chain extenders, possibly for recycle problems, crosslinkers, to enhance mechanical properties of polymeric materials, branchers, to selectively introduce ramifications in linear polymers, and compatibilizers, to favor the formation of blends between originally incompatible organic macromolecules. The great versatility of the synthetic methods put forward for these substrates, together with the ease of controlling their modification, functionalization and reactivity are important parameters for the evaluation of which type of use is more feasible for these trimers. The importance of cyclophosphazenes bearing organic polymeric chains, azide groups, 2‐oxazoline derivatives and oxirane rings in connection with organic conventional macromolecules is critically highlighted.

Time-dependent speciation studies have been carried out on the ternary Al^III−citrate (A)−phosphate (B) system in order to clarify the solution state of Al^III in blood serum. The potentiometric results indicate that ternary complexes predominate both in freshly prepared mixtures and at equilibrium. The ternary species AlAB and AlABH−1 and the binary species AlAH−1 and AlBH−1 are present at physiological pH. As the solution ages the amount of the trinuclear species [Al3(AH−1)3(OH)]⁴⁻ increases at the expense of the mononuclear binary and ternary complexes. ³¹P NMR spectra measured at neutral pH provide corroborating evidence of the formation of the ternary complexes AlAB and AlABH−1 and binary species AlBH−1 and Al2BH−3 found potentiometrically. Time-dependent ¹H NMR measurements show that monodentate phosphate can slowly displace citrate from the otherwise very stable structure of the trinuclear species [Al3(AH−1)3(OH)]⁴⁻. At blood serum concentrations [c(Al^III) = 3 μM], Al^III is mostly bound to citrate either in binary species or in the ternary species formed with phosphate. However, with increasing Al^III concentrations binding to phosphate becomes more important.

The reactions of the nitrile complexes cis- and trans-[PtCl2(NCR)2] with S(+)-2-chloro-1-propanol in the presence of 2 equiv. of n-BuLi afford the chiral oxazoline complexes cis- and trans-[PtCl2{(R)-N=C(R)OCH2CH(Me)}2] [cis, R=Me (1), cis, R=Ph (2); trans, R=Ph (3)]. The structures of 1and 2were determined by X-ray analysis which allowed to establish the Rconfiguration of the oxazoline rings. The reactions of cis- and trans-[PtCl2(NCR)2] with S(+)-2-chloro-1-phenylethanol and R(−)-2-chloro-1-phenylethanol in the presence of 2 equiv. of n-BuLi afford the oxazoline complexes cis- and trans-[PtCl2{(S)-N=C(R)OCH(Ph)CH2}2] [cis, R=Me (4), cis, R=Ph (5); trans, R=Ph (6)] and cis- and trans-[PtCl2{(R)-N=C(R)OCH(Ph)CH2}2] [cis, R=Me (7), trans, R=Me (8); trans, R=Ph (9)]. The structure of 6was determined by an X-ray investigation which allowed to establish the Sconfiguration of the oxazoline rings. The proposed mechanism for the nitrile to chiral oxazoline conversion entails nucleophilic attack of the alkoxide, generated by deprotonation reaction of the corresponding alcohol with n-BuLi, followed by intramolecular cyclization. This latter step proceeds with complete inversion of configuration at the chiral carbon atom for 1–3, while with retention of configuration for 4–9.

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In this study are reported the syntheses of three bis(diarylhydrazonecarbonyl)methylene derivatives [{ArPhC&dbond;NNH&bond;C(O)}2CH2] [Ar = 2&bond;C5H4N (5), C6H5 (6), and 2-C4H3S (7)], obtained by condensation of corresponding hydrazones with carbon suboxide, C3O2. The solid-state self-assembly of these carbonyl derivatives, giving rise to polymeric and dimeric networks, is described. In the formation of these structural features, in addition to N—H· · ·O&dbond;C intermolecular hydrogen bonds, stabilizing intramolecular NH· · · π (systems) and intermolecular CO· · ·π (systems) interactions also seem to play an important role. Solution ¹H-nmr data of compounds 5–7 indicate that the polymeric and dimeric structures are not maintained in solution and show the occurrence of keto-enolic equilibria. © 1999 John Wiley & Sons, Inc. Biopoly 49: 541–549, 1999

The cyanoguanidine complex cis-[Pt(NCNC(NH2)2)2(PPh3)2][BPh4]2, prepared by reacting cis-[PtCl2(PPh3)2] with cyanoguanidine in the presence of Na[BPh4], readily reacts with methanol to give cis-[(PPh3)2PtNHC(OMe) = NC(NH2) = NH)] [BPh4] containing a novel type of azametallcycle whose molecuar structure is established by X-ray crystallography. Its formation involves metal-promoted nucleophilic addition of the alcohol to the cyano group of a cyanoguanidine ligand, combined with deprotonation of the guanidine unit which then chelates the Pt(II) centre.

In this article, the general procedure for stabilizing polyorganophosphazenes against the damage induced in these substrates by photooxidation reactions under accelerated conditions is explored. This method is based on the preventive grafting of succinic anhydride groups onto selected polyphosphazenes induced by light excitation, followed by the reaction of the functionalized phosphazene substrates with amino-terminated HALS groups. HALS moieties, in fact, are able to strongly inhibit the photooxidation of phosphazene films under accelerated conditions even when randomly attached to the polyphosphazene materials in very low amounts. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:217–231, 1997

In this paper we report the synthesis and the characterization of cyclo- and polyphosphazenes supporting Rose Bengal. These substrates are suitable for the photosensitized generation of singlet oxygen, both in homogeneous and in heterogeneous phase. The efficiency of1O2 production has been measured in homogeneous solution using, as photosensitizer, the cyclophosphazene-bound Rose Bengal and considering, as testing reaction, the oxidation of 1,3-diphenylisobenzofuran; it was found comparable to that of free Rose Bengal in the same experimental conditions.

The reactions of carbon suboxide, C3O2, with a series of stabilized triphenylarsoranes, Ph3As=CHX (X = CN, COOMe, COMe, COPh, COC6H4-p-OMe), yield two different kinds of cmpounds. When X = CN, COOMe the reaction proceeds in a 2:1 ratio (ylide: C3C2) yielding open-chain maloni bis-ylidic compounds (1a,b) whereas in the cases of X = COMe, COPh, COC6H4-p-OME only 1:1 cyclic zwitterionic compounds (2a-c) are obtained. The crystal structure of the bis-ylidic compound 1b has been determined. The crystalas are monoclinic, space group C2/c with a = 19.296(8), b = 10.179(5), c = 19.743(8) A˚, β = 97.3(1)°, Z = 4. The molecular parameters are consistent with an important contribution of the dipolar form −O&z.sbnd;C=C&z.sbnd;As+. Carbon suboxide has been reactde also with Ph3P=CHX (X = COC6H4-p-OMe, COOMe) giving the cyclic zwitterionic compounds 3 when X = COC6H4-p-OME, whereas when X = COOMe a mixture of products has been obtained.

Review: 106 refs.

Large interest is into the determination of body fluids because of changes in body water in a wide variety of physiological and pathological conditions. Here methods based on dilution of tracers, are reported, for the extracellular water (ECW) and total body water (TBW) determinations on the same sample. As for ECW, bromide is used as tracer and its concentration is determined by energy dispersive X-ray spectrometry; while as for TBW, D2O is used as tracer and HOD is determined by FT IR. Both methods represent significant improvements with respect the procedures described in the literature in terms of availability, reproducibility and accuracy.