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The Zaltoprofen/4,4'-Bipyridine system gives rise to two co-crystals of different compositions both endowed - in water and in buffer solution at pH 4.5 - with considerably higher solubility and dissolution rate than the pure drug. The qualitative and quantitative analysis of the DSC measurements, carried out on samples made up of mixtures prepared according to different methodologies, allows us to elaborate and propose an accurate thermodynamic model that fully takes into account the qualitative aspects of the complex experimental framework and which provides quantitative predictions (reaction enthalpies and compositions of the co-crystals) in excellent agreement with the experimental results. Co-crystal formation and cocrystal compositions were confirmed by X-ray diffraction measurements as well as by FT-IR and NMR spectroscopy measurements. The quantitative processing of DSC measurements rationalizes and deepens the scientific aspects underlying the so-called Tammann's triangle and constitutes a model of general validity. The work shows that DSC has enormous potential, which however can be fully exploited only by paying adequate attention to the experimental aspects and the quantitative processing of the measurements.

Cleaning is one of the most important, essential, and delicate operation which has to be handled by conservators before applying new materials to any substrates. In past decades, nanotechnology introduced new concepts and materials in the conservation field, which have been providing many advantageous performances, especially higher than older materials. As a result, the conservators have already started to use nanomaterials in the cleaning processes of artifacts. Taking into consideration this new approach, our study has focused on using nano-structured emulsions (NSE) as smart cleaning materials for removing polymer coatings (e.g., acrylic polymers). For this purpose, Paraloid B-72 was applied on three different substrates (glass, Lecce stone, and Arenaria stone) and cleaning was performed by a specific nano-structured emulsion (NSE) based on an eco-friendly surfactant (EcoSurf) and two organic solvents in different proportions. In order to better understand the interaction of surfactant and organic solvents with polymer coating, plain EcoSurf in water was also used for comparison. In this study, the decay process of the considered polymer was also deeply studied, because it directly affects the cleaning effectiveness. Coated specimens of the different substrates were artificially aged and examined by different techniques: chromatic variations and contact angle measurements, optical microscopy, FTIR, and SEM-EDS. This material characterization process is important to understand the colour, morphology, and micro-structural difference, and the changes of hydrophobic behaviour as well as chemical composition of Paraloid B-72 polymer due to different ageing processes. After that, substrates coated with both unaged and aged polymer were cleaned by NSE according to the direct-contact procedure and cellulose pulp method. Preliminary analyses suggested that the direct-contact cleaning performed by nano-emulsion (i.e., NSE) induced a complete removal of the acrylic polymer, despite that this method is not recommended for the artifacts and can be hardly applicable in real cases. On the other hand, experimental results showed that satisfactory cleaning of stone substrates can be obtained by using NSE/the cellulose pulp system.

The conversion-alloying compounds have been identified as promising anode materials for sodium ion batteries (SIBs). One of them, SnO2, with an enormous theoretical capacity of 1558 mAh g−1 is an interesting candidate, also due to its low cost, environmental friendliness and wide availability of tin. However, many drawbacks limit its application in commercial batteries. In this paper, SnO2 has been synthesized from cheap reagents by using simple and easily scalable coprecipitation synthesis routes obtaining nanoparticles with sizes between 2 and 14 nm with almost spherical morphologies. The reasons of the failure of the alloying/de-alloying process were investigated by combining the results obtained from common electrochemical techniques, providing useful examples for the investigation of every material with analogous electrochemical features. Thanks to cyclic voltammetry, different reaction paths were detected for the two samples. The first cycle irreversibility was well characterized with electrochemical impedance spectroscopy, showing interesting trends in the values of the resistance. Galvanostatic cycling with potential limitations was employed to quantify the irreversibility, finding out that the most crystalline sample reached the terminal phase in the Sn-Na system (Na15Sn4), while the least crystalline sample could not achieve such a result (Na3Sn). The crystallinity of SnO2 was determined to be a key parameter, often neglected, for the realization of satisfactory anode compounds.

In the current study, an experimental approach for the further understanding of the LiH hydrolysis reaction for hydrogen production is considered. The experimental work has been undertaken under small scale conditions by utilising fixed bed reactors. The hydrolysis reaction has been studied at several oven temperatures (150 °C, 300 °C and 500 °C). The favourable driving potentials for the hydrolysis reactions were identified by the utilisation of the Gibbs free energy analysis. The main outcome of the study is the deceleration of the reaction pace due to the formation of the by-product layers during the reaction. At the initial stage, due to the contact of steam with the unreacted and fresh LiH surface, the reaction proceeds on a fast pace, while the formation of the layers tends to decelerate the diffusion of steam into the core of material, forcing the production step to be slower. The hydrogen yield was found to be more than 90% of the theoretical value for all the reaction temperatures. Finally, a scenario of a hybrid-electric propulsion system for Unmanned Aerial Vehicles (UAVs) including Li-ion battery, Proton Membrane Fuel Cell (PEMFC) and an on-board hydrogen production system based on LiH hydrolysis is introduced and studied.

Low-cost and simple methods are constantly chased in order to produce less expensive lithium-ion batteries (LIBs) while possibly increasing the energy and power density as well as the volumetric capacity in order to boost a rapid decarbonization of the transport sector. Li alloys and tin-carbon composites are promising candidates as anode materials for LIBs both in terms of capacity and cycle life. In the present paper, electrospinning was employed in the preparation of Sn/SnOx@C composites, where tin and tin oxides were homogeneously dispersed in a carbonaceous matrix of carbon nanofibers. The resulting self-standing and light electrode showed a greatly enhanced performance compared to a conventional electrode based on the same starting materials that are simply mixed to obtain a slurry then deposited on a Cu foil. Fast kinetics were achieved with more than 90% of the reaction that resulted being surface-controlled, and stable capacities of about 300 mAh/g over 500 cycles were obtained at a current density of 0.5 A/g.

Green chemistry 24(10), 4153 - 4163 (2022). doi:10.1039/D1GC04709D, To reduce the carbon footprint associated with the production of hydrogen storage materials and to reduce their cost, we pursue the possibility of obtaining high-quality hydride-based materials from industrial metals waste. In particular, in this manuscript, we propose a method for obtaining high-quality NaAlH$_4$, starting from the Al-based automotive recycled alloy DIN-GDAlSi10Mg(Cu). The hydrogen storage properties of the material obtained by ball milling NaH and DIN-GDAlSi10Mg(Cu) under a hydrogen atmosphere were comprehensively explored via a broad range of experimental techniques, e.g. volumetric analysis, ex situ X-ray diffraction (XRD), in situ synchrotron radiation powder X-ray diffraction (SR-PXD), scanning electron microscopy (SEM), and differential thermal analysis (DTA). These investigations show that NaAlH$_4$ was successfully synthesized and that its properties are comparable with those of high-purity commercial NaAlH$_4$., Published by RSC, Cambridge

Background: Macroaggregated human serum albumin (MAA) properties are widely used in nuclear medicine, labelled with 99mTc. The aim of this study is to improve the knowledge about the morphology, size, dimension and physical–chemical characteristics of MAA and their bond with 99mTc and 68Ga. Methods: Commercial kits of MAA (Pulmocis®) were used. Characterisation through experiments based on SEM, DLS and Stokes’ Law were carried out. In vitro experiments for Langmuir isotherms and pH studies on radiolabelling were performed and the stability of the radiometal complex was verified through competition reactions. Results: The study settles the MAA dimension within the range 43–51 μm. The Langmuir isotherm reveals for [99mTc]MAA: Bmax (46.32), h (2.36); for [68Ga]MAA: Bmax (44.54), h (0.893). Dual labelling reveals that MAA does not discriminate different radioisotopes. Experiments on pH placed the optimal pH for labelling with 99mTc at 6. Conclusion: Radiolabelling of MAA is possible with high efficiency. The nondiscriminatory MAA bonds make this drug suitable for radiolabelling with different radioisotopes or for dual labelling. This finding illustrates the need to continue investigating MAA chemical and physical characteristics to allow for secure labelling with different isotopes.

The eco-friendly method of kneading was here used to synthesize a cocrystal of probenecid, an uricosuric drug used in treating gout and hyperuricemia, with the aim to improve its pharmaceutical behavior. Benzamide was selected as a co-former showing functional groups favorable to the formation of supramolecular synthons with the active principle. The kneading product was characterized by a range of experimental techniques (microscopic, spectroscopic, thermal and diffractometric) all proving the formation of the new multicomponent crystal. In particular, the FT-IR and NMR techniques showed that an important change of hydrogen bonds network takes place in the kneading product and that the acid–acid interaction in the pristine drug is replaced with the related acid-amide one in the cocrystal. The cocrystal solubility and dissolution rate measured in several biorelevant fluids showed an actual improvement with respect to the pure drug.

The aim of this study was to synthetize cocrystals of nateglinide, an antidiabetic agent of biopharmaceutics classification system Class IIa, as a strategy to improve both the solubility and the dissolution rate of the drug. Benzamide was selected by a screening procedure as a suitable coformer, and binary mixtures with different compositions were prepared and analyzed by differential scanning calorimetry (DSC). An in-depth analysis of DSC data allowed obtaining both the eutectic mixture and cocrystal compositions. The rationale of such an analysis was highlighted and explained. Cocrystals were prepared by kneading and solvent evaporation. Their formation was proved by DSC and confirmed by X-ray powder diffraction, solid-state nuclear magnetic resonance, and Fourier-transform infrared spectroscopy. The functional groups involved in the interaction leading to cocrystals formation were investigated by spectroscopic techniques. The in vitro dissolution profiles show that cocrystals have definite better pharmaceutical performances than the pure drug.

The present work is a concrete example of how physico-chemical studies, if performed in depth, are crucial to understand the behavior of pharmaceutical solids and constitute a solid basis for the control of the reproducibility of the industrial batches. In particular, a deep study of the thermal behavior of glipizide, a hypoglycemic drug, was carried out with the aim of clarifying whether the recognition of its polymorphic forms can really be done on the basis of the endothermic peak that the literature studies attribute to the melting of the compound. A number of analytical techniques were used: thermal techniques (DSC, TGA), X-ray powder diffraction (XRPD), FT-IR spectroscopy and scanning electron microscopy (SEM). Great attention was paid to the experimental design and to the interpretation of the combined results obtained by all these techniques. We proved that the attribution of the endothermic peak shown by glipizide to its melting was actually wrong. The DSC peak is no doubt triggered by a decomposition process that involves gas evolution (cyclohexanamine and carbon dioxide) and formation of 5-methyl-N-[2-(4-sulphamoylphenyl) ethyl] pyrazine-2-carboxamide, which remains as decomposition residue. Thermal treatments properly designed and the combined use of DSC with FT-IR and XRPD led to identifying a new polymorphic form of 5-methyl-N-[2-(4-sulphamoylphenyl) ethyl] pyrazine-2-carboxamide, which is obtained by crystallization from the melt. Hence, our results put into evidence that the check of the polymorphic form of glipizide cannot be based on the temperature values of the DSC peak, since such a peak is due to a decomposition process whose Tonset value is strongly affected by the particle size. Kinetic studies of the decomposition process show the high stability of solid glipizide at room temperature.

The addition of transition metals to alkali intercalated fullerides proved to enhance their already good hydrogen absorption properties. Herein we present a study based on two different synthetic strategies, allowing the addition of nickel as aggregates with different size to the lithium fulleride Li6C60: the former is based on the metathesis of nickel chloride, while the latter on the thermal decomposition of nickel carbonyl clusters. The hydrogen-storage properties of the obtained materials have been investigated with manometric and calorimetric measurements, which indicated a clear enhancement of the final absorption value and kinetics with respect to pristine Li6C60, as a consequence of nickel surface catalytic activity towards hydrogen molecules dissociation. We found up to 10 % increase of the total H2 weight % absorbed (5.5 wt% H2) in presence of Ni aggregates. Furthermore, the control of the transition metal particles size distribution allowed reducing the hydrogen desorption enthalpy of the systems.

Sulindac is a nonsteroidal anti-inflammatory drug with poor water solubility. This study presents a way to increase its dissolution rate while reducing the risk of gastrointestinal side effects. This approach considers the paired administration of sulindac with the gastroprotector proglumide, in the form of eutectic mixture. Theoretical and experimental methods proved that sulindac and proglumide form a simple eutectic system containing a molar fraction of proglumide of 0.7 at the eutectic point. The product with the eutectic composition, obtained by solvent evaporation, shows a significant improvement in the sulindac dissolution rate compared to the corresponding physical mixture.

Lanthanum cobaltite, LaCoO3, finds applications as an oxidation and reduction catalyst in gas-sensing materials and in electrode materials for high-temperature fuel cells. The compound has been synthesized through several routes aimed at obtaining LaCoO3 at lower temperatures. We propose a synthetic procedure based on the combined use of mechanical and thermal energy on mixtures of Co(II) oxalate dehydrate and La acetate sesquihydrate. We studied the reactions taking place by increasing the temperature. The study has been performed either on mixtures prepared by a simple physical mixing of the reactants or on the same mixtures after having been subjected to mechanical activation by high-energy milling. The products formed in the mixtures by annealing at different temperatures have been characterized by means of different experimental techniques (thermogravimetric analysis, XRPD, IR, scanning electron microscopy).

Lanthanum ferrite, LaFeO3 (LF), has raised considerable interest since it can be used in many applications such as solid-oxide fuel cell electrode, sensor material (H2O and ethanol) and catalyst. Since the conventional ceramic route of synthesis has some disadvantages, mainly related to an exaggerated grain growth, LF has been prepared by different methods including combustion synthesis, sol–gel, hydrothermal processes, polymerizable complex method and mechanochemistry. As concerns this last method, a problem occurs due to the moisture sensitivity of La2O3. To overcome the problem, we used lanthanum acetate sesquihydrate [La(CH3COO)3·1.5H2O] and iron (II) oxalate dehydrate [FeC2O4·2H2O] as precursors. The mechanism of the solid-state reactions in the mixtures has been studied by TG–DSC and XRPD. Synthesis of LaFeO3 has been realized by annealing the mechanically activated mixtures for 3 h at temperatures between 500 and 800 °C. While LF prepared at 500 °C

The aim of this work was to search for new polymorphic forms of febantel, an anthelminthic drug of great present interest for the veterinary industry. Solvent-based recrystallization, thermal and mechanical treatments and spray drying were chosen to discover new solid forms. The solids obtained were physicochemically characterized by thermal techniques (DSC and TG), FTIR spectroscopy, laboratory and synchrotron X-ray powder diffraction and scanning electron microscopy. Our work leads to obtain a new solid form never described in the literature. In particular, the new polymorph was obtained by the anti-solvent method and the crystallization from isopropanol. The experimental conditions of crystallization favorable to the formation of the highest amount of the new solid phase were selected. The new phase shows a thermal, spectroscopic and diffractometric behavior unique. Furthermore, the preliminary structure investigation suggests two possible crystal systems: an orthorhombic or a monoclinic one, with really comparable lattice parameters and cell volume. Measurements put into evidence that the new phase is a metastable polymorph that is in monotropic relationship with the stable and known form.

The use of peptides in paper-based analytics is a highly appealing field, yet it suffers from severe limitations. This is mostly due to the loss of effective target recognition properties of this relatively small bioprobes upon nonspecific adsorption onto cellulose substrates. Here, we address this issue by introducing a simple polymer-based strategy to obtain clickable cellulosic surfaces, that we exploited for the chemoselective bioconjugation of peptide bioprobes. Our method largely outperformed standard adsorption-based immobilization strategy in a challenging, real-case immunoassay, namely the diagnostic discrimination of Zika+ individuals from healthy controls. Of note, the clickable polymeric coating not only allows efficient peptides bioconjugation, but it provides favorable anti-fouling properties to the cellulosic support. We envisage our strategy to broaden the repertoire of cellulosic materials manipulation and promote a renewed interest in peptide-based paper bioassays.

We report on the preparation of a novel hierarchically-porous super-activated carbon originating from organic waste with specific surface area exceeding 3000 m2/g, obtained starting from biochar derived by the pyrolysis of poultry litter. The chemical activation process proved to be efficient to remove the majority of impurities other than carbon, stabilizing a highly porous hierarchical structure with local graphene-like morphology. The presence of P and S with concentration below 0.1 wt% distinguishes this activated carbon from the usual ones obtained from vegetal sources. Thanks to these features, the obtained porous compound demonstrated to behave as an excellent electrode material for high-performance symmetric supercapacitors, reaching high specific capacitance up to 229 (13) F/g. Remarkably, the devices also supply high current density of 10 A/g without using any conducting additives and display high power density and reliability. Moreover, these optimal performances have been obtained operating by using simple eco-friendly electrolytes, like KOH and Na2SO4 aqueous solutions. The availability, the biocompatibility and the inexpensiveness of the starting materials, together with the low environmental impact of the electrolyte, suggest possible large-scale applications for such devices, for example in the field of transportation or in renewable energy-grids, but also in the field of bio-medicine.

Several different milling parameters (additive content, rotation velocity, ball-to-powder ratio, degree of filling, and time) affect the hydrogen absorption and desorption properties of a reactive hydride composite (RHC). In this paper, these effects were thoroughly tested and analyzed. The milling process investigated in such detail was performed on the 2LiH-MgB2 system doped with TiCl3. Applying an upgraded empirical model, the transfer of energy to the material during the milling process was determined. In this way, it is possible to compare the obtained experimental results with those from processes at different scales. In addition, the different milling parameters were evaluated independently according to their individual effect on the transferred energy. Their influence on the reaction kinetics and hydrogen capacity was discussed and the results were correlated to characteristics like particle and crystallite size, specific surface area, presence of nucleation sites and contaminants. Finally, an optimal value for the transferred energy was determined, above which the powder characteristics do not change and therefore the RHC system properties do not further improve. Fil: Jepsen, Julian. Helmholtz zentrum Geesthacht; Alemania. Helmut Schmidt University; Alemania Fil: Capurso, Giovanni. Helmholtz zentrum Geesthacht; Alemania Fil: Puszkiel, Julián Atilio. Helmholtz zentrum Geesthacht; Alemania. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina Fil: Busch, Nina. Helmholtz zentrum Geesthacht; Alemania Fil: Werner, Tobias. Helmholtz zentrum Geesthacht; Alemania Fil: Milanese, Chiara. Universita Degli Studi Di Pavia; Italia Fil: Girella, Alessandro. Universita Degli Studi Di Pavia; Italia Fil: Von Colbe, José Bellosta. Helmholtz zentrum Geesthacht; Alemania Fil: Dornheim, Martin. Helmholtz zentrum Geesthacht; Alemania Fil: Klassen, Thomas. Helmholtz zentrum Geesthacht; Alemania. Helmut Schmidt University; Alemania

The mechanism of Bi4Ti3O12 formation starting from the two constituent oxides has been studied. Starting from a physical mixture, a solid-state reaction occurs between the two oxides that leads at ≈700 °C to a mixture of the two ternary oxides Bi12TiO20 + Bi4Ti3O12 along with unreacted precursor oxides. At T ≈ 830 °C Bi12TiO20 reacts with TiO2 forming Bi4Ti3O12 and, finally, at T ≈ 850 °C, the residual Bi12TiO20 undergoes the peritectic reaction that produces Bi4Ti3O12 plus a liquid phase. However, the formation of Bi4Ti3O12 is not complete at temperatures as high as 900 °C. Starting from a mechanically activated mixture, the intermediate Bi12TiO20 only forms as a minority phase at a lower temperature (T ≈ 550 °C), and then it rapidly reacts to give Bi4Ti3O12. No trace of the peritectic reaction is found in the case of the activated mixture. The complete formation of Bi4Ti3O12 can be obtained by 3-h annealing of the activated mixture at T ≥ 650 °C. The heat capacity of the product phase Bi4Ti3O12 has also been measured in the temperature range 50–300 °C.

Hybrid composite made of glauconite and polyaniline was prepared in aqueous solution of citric acid. Scanning electron microscopy combined with energy dispersive X-ray analysis shows uniform aggregates made of glauconite microparticles and polyaniline matrix. The results of X-ray powder diffraction suggest that: (1) citric acid used for the polymerisation of aniline causes formation of emeraldine salt where macromolecular ordering in the amorphous polymer takes place; (2) no chemical interaction between glauconite and emeraldine takes place in the prepared composite. FT-IR spectra of the prepared polymer and composite show features indicating all the functional groups that are present in the diiminoquinone–diaminobenzene state of polyaniline. Thermal stability of the composite was higher than the prepared polymer suggesting the occurrence of an interphase interaction between glauconite and emeraldine. After pyrolysis in purified nitrogen the composite still remained glauconite, and e-Fe3N together with amorphous and graphitic carbon were found as reaction products. The values of electrical conductivity and magnetization of the composite suggest that optimization of these values might be achieved based upon the relationship between glauconite and polyaniline.

New insights into the reaction pathways of different potassium/magnesium amide-hydride based systems are discussed. In situ SR-PXD experiments were for the first time performed in order to reveal the evolution of the phases connected with the hydrogen releasing processes. Evidence of a new K-N-H intermediate is shown and discussed with particular focus on structural modification. Based on these results, a new reaction mechanism of amide-hydride anionic exchange is proposed.

This paper deals with the preparation of new poly(High Internal Phase Emulsion) [polyHIPE] materials, templated by varying different preparation parameters. The obtained systems are based on acrylic monomers, polymerized by free radical polymerization initiated by potassium persulfate and the redox initiator N,N,N′,N′-tetramethylethylenediamine (TEMED) to gain a crosslinked system at room temperature. To get a functional material, glycidyl methacrylate (GMA) has been introduced in the polymeric structure. The HIPE system was effectively stabilized by a co-polymer surfactant, while a polysorbate surfactant did not stabilize the emulsion. Water as the internal phase with its content ranging from 80 to 90% was explored. A deep characterization of the materials, including SEM, DSC, TGA, BET, swelling and weight loss was carried out. The developed systems are promising and can find successful applications for analytical and biomedical purposes.

In this work, the polymorphic α-magnesium borohydride form was infiltrated by wet impregnation using tetrahydrofuran (THF) as solvent and subcritical carbon dioxide as innovative drying process. Pressure infiltration at high temperature was also tested as another promising method for confinement. After infiltration, onset decomposition temperature was reduced from 280 °C into 220 °C using high pressure infiltration and down to 100 °C using wet impregnation followed by CO2 drying. Faster kinetics were obtained in both cases due the possible particle size reduction in the precipitation process of the complex hydride and the presence of silica, which could behave as an additive. It is the first time that this complex borohydride is 6.1 wt% H2 reversible performing the rehydrogenation at moderate conditions of 390 °C and 120 bar H2 using silica as support. Different values were obtained after infiltration method due to the different intermediates that were obtained after the first dehydrogenation.

Reaction kinetic behaviour and cycling stability of the 2LiBH4-MgH2 reactive hydride composite (Li-RHC) are experimentally determined and analysed as a basis for the design and development of hydrogen storage tanks. In addition to the determination and discussion about the properties; different measurement methods are applied and compared. The activation energies for both hydrogenation and dehydrogenation are determined by the Kissinger method and via the fitting of solid-state reaction kinetic models to isothermal volumetric measurements. Furthermore, the hydrogen absorption-desorption cycling stability is assessed by titration measurements. Finally, the kinetic behaviour and the reversible hydrogen storage capacity of the Li-RHC are discussed. Fil: Jepsen, Julian. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania Fil: Milanese, Chiara. Università degli Studi di Pavia; Italia Fil: Puszkiel, Julián Atilio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina Fil: Girella, Alessandro. Università degli Studi di Pavia; Italia Fil: Schiavo, Benedetto. Università degli Studi di Palermo; Italia Fil: Lozano, Gustavo A.. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania Fil: Capurso, Giovanni. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania Fil: Von Colbe, José M. Bellosta. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania Fil: Marini, Amedeo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Kabelac, Stephan. Leibniz Universität Hannover; Alemania Fil: Dornheim, Martin. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania Fil: Klassen, Thomas. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania

Thermodynamic and heat transfer properties of the 2LiBH4-MgH2 composite (Li-RHC) system are experimentally determined and studied as a basis for the design and development of hydrogen storage tanks. Besides the determination and discussion of the properties, different measurement methods are applied and compared to each other. Regarding thermodynamics, reaction enthalpy and entropy are determined by pressure-concentration-isotherms and coupled manometric-calorimetric measurements. For thermal diffusivity calculation, the specific heat capacity is measured by high-pressure differential scanning calorimetry and the effective thermal conductivity is determined by the transient plane source technique and in situ thermocell. Based on the results obtained from the thermodynamics and the assessment of the heat transfer properties, the reaction mechanism of the Li-RHC and the issues related to the scale-up for larger hydrogen storage systems are discussed in detail. Fil: Jepsen, Julian. Helmholtz-Zentrum Geesthacht; Alemania Fil: Milanese, Chiara. University of Pavia; Italia Fil: Puszkiel, Julián Atilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Helmholtz-Zentrum Geesthacht; Alemania Fil: Girella, Alessandro. University of Pavia; Italia Fil: Schiavo, Benedetto. Universidad de Palermo; Argentina. Istituto per le Tecnologie Avanzate; Italia Fil: Lozano, Gustavo A.. Helmholtz-Zentrum Geesthacht; Alemania. BASF; Alemania Fil: Capurso, Giovanni. Helmholtz-Zentrum Geesthacht; Alemania Fil: Von Colbe, José M. Bellosta. Helmholtz-Zentrum Geesthacht; Alemania Fil: Marini, Amedeo. University of Pavia; Italia Fil: Kabelac, Stephan. Leibniz Universität Hannover; Alemania Fil: Dornheim, Martin. Helmholtz-Zentrum Geesthacht; Alemania Fil: Klassen, Thomas. Helmholtz-Zentrum Geesthacht; Alemania

We herein report on the synthesis of mixed alkali cluster intercalated fullerides NaxLiy−xC60 (y = 12; x = 1–6) by a two-steps mechanochemical reaction of fullerene with sodium and lithium. These compounds crystallize in the cubic lattice of C60 displaying a contracted lattice parameter with respect to the Na6C60 parent structure. The analysis of the hydrogen sorption behaviour shows a slight decrease in the dehydrogenation enthalpy for y = 12 with respect to the sodium free member. Raman spectroscopy highlighted a partial electron transfer from alkali metals to C60, suggesting the presence of charged sodium/lithium clusters. Finally, we applied muon spectroscopy to understand the different hydrogenation mechanisms in NaxLi6−xC60 and NaxLi12−xC60 and explain their different performance.

Magnesium has been studied as a potential hydrogen storage material for several decades because of its relatively high hydrogen storage capacity, fast sorption kinetics (when doped with transition metal based additives), and abundance. This research aims to study the possibility to use waste magnesium alloys to produce good quality MgH2. The production costs of hydrogen storage materials is still one of the major barriers disabling scale up for mobile or stationary application. The recycling of magnesium-based waste to produce magnesium hydride will significantly contribute to the cost reduction of this material. This study focuses on the effect of different parameters such as the addition of graphite and/or Nb2O5 as well as the effect of milling time on the material hydrogenation/de-hydrogenation performances. In addition, morphology and microstructural features are also evaluated for all the investigated materials.

Gold and gold–palladium nanodeposits were obtained by pulse electrolysis in dimethylformamide with 4×10−3 M HAuCl4 and in dimethyl sulfoxide solution with a mixture of 4×10−3 M HAuCl4 and 4×10−3 M PdCl2, respectively. Isolated gold nanoparticles of about 15 nm in diameter were found by SEM observation after 6 ms of electrochemical deposition. Three pulse and pause periods with duration of 6 ms and 300 ms respectively led to an increase in the particle size approximately two times. In case of gold-palladium deposition, no particles were detected after 10 electrochemical cycles while after 50 cycles 10–35 nm nanoparticles were found. Detailed SEM analysis of electrode surface suggested that at the beginning of electrochemical deposition the growth of gold/nucleation of gold–palladium NPs is a preference for mono-Au/bimetallic Au–Pd system.

The work deals with the synthesis of multiferroic BiFeO3 starting from mixture of Bi citrate and Fe(II) oxalate dihydrate. By combined TG-DSC and XRPD experiments it is put into evidence that the mechanically activated mixture absorbs an extra enthalpy (+235 kJ) that is due to the reaction between the forming oxides. Furthermore it is shown that mechanical activation of the starting mixture sensibly enhances the formation of Bi ferrite. Indeed BiFeO3 is obtained by annealing the activated mixture at temperatures as low as 750 °C while this does not happen by annealing the physical mixture at temperatures up to 800 °C. Finally by MTDSC (Modulated Temperature Differential Scanning Calorimetry) we measured the thermal capacity of BiFeO3 obtained from the annealed activated mixture.

Many synthesis procedures have been worked out to prepare CaSnO3. A great deal of them resort to the classical ceramic method that implies a very high temperature treatment (1300–1500 °C) of the component oxides mixture. To avoid such high temperature treatment, many alternative routes have been proposed. In this paper stoichiometric mixtures of Ca citrate tetrahydrate and Sn(II) oxalate have been mechanically activated by high energy milling. The reactions taking place in the mixtures during annealing have been studied by coupled TG–DSC measurements, XRPD and diffuse reflectance FT-IR spectroscopy. It has been established that the stage of mechanical activation allows the synthesis to be completed by 3 h-annealing at 850 °C.

Objective: To improve the pharmaceutical behavior of the oral antidiabetic agent gliclazide through the synthesis of multicomponent crystals with tromethamine. Methods: Multicomponent crystals were prepared by solvent evaporation method, kneading, and combining mechanical and thermal activation. DSC, FT-IR spectroscopy, X-ray diffraction, SEM-EDS, and SSNMR were used to investigate their formation. Measurements of solubility and dissolution rate were carried out for the pharmaceutical characterization. Results: The formation of multicomponent crystals of gliclazide and tromethamine was confirmed by all the techniques. In particular, FT-IR and NMR measurements revealed that the interaction between drug and coformer leads to significant changes of the hydrogen bond scheme, and that almost all the functional groups of the two molecules are involved. The dissolution profile of the new phase is significantly better than that of both pure gliclazide and of the reference commercial product Diabrezide®. Conclusions: The new system shows an improved pharmaceutical behavior and could be formulated in a dosage form to obtain a rapid and complete release of the drug available for absorption

Lithium and hydrogen dynamics in Li12C60 and Li12C60Hy are investigated by means of 7Li and 1H solid state Nuclear Magnetic Resonance (NMR) in the temperature range 80–550 K. Differential scanning calorimetry characterization on the hydrogen sorption and X-rays structural analysis are also reported. In the pure phase, the 7Li results show a thermally activated dynamics that can be associated to Li motions within the crystal interstices. Upon hydrogenation, Li ionic motion is considerably hindered by the presence of hydrofullerene molecules. The 1H measurements show that C–H bonds are stable on the local scale up to 400–450 K. The NMR results at higher temperatures are compatible with a H diffusion mechanism which anticipates the H desorption process.

Through the substitution of Li with Na in Li6C60, we synthesized a series of mixed alkali cluster intercalated fullerides, NaxLi6−xC60. These compounds share lattices of Na6C60 and Li6C60 with a cubic parameter linearly dependent on x. H2 absorption and desorption were studied by means of charge/discharge kinetic measurements and coupled calorimetric–manometric evaluation. By varying the stoichiometry, we found the best compromise among the absorption rate, temperature and amount of hydrogen for x = 0.5 and 1. Small concentrations of Na substituted to Li significantly lower the absorption temperature of Li6C60, improving the hydrogenation capacity, the kinetics, and the dehydrogenation enthalpy, the latter being 43.8 kJ mol−1 H2 for x = 1. This study moves further toward the utilization of intercalated fullerides for hydrogen storage applications.

The synthesis of strontium metastannate (SrSnO3) has been performed by coupling mechanical activation with thermal activation of SnC2O4-SrCO3 mixtures. The solid-state reaction has been studied by TG-DSC analysis and powder X-ray diffraction. By annealing experiments performed on physical mixtures (no mechanical activation) it has been assessed that the formation of SrSnO3 occurs through the intermediate Sr2SnO4 and is complete only after annealing at 1400 °C. By performing the annealing experiments on activated mixtures it has been established that the formation of SrSnO3 takes place directly at temperatures between 800 and 1000 °C. The SrSnO3 samples obtained at 800 and 900 °C show, by TG analysis, mass loss processes that suggest that SrSnO3 obtained at these temperatures absorbs H2O and CO2 from the air so that its use as gas sensor can be envisaged. This is no longer true for the sample obtained at 1000 °C or above

This paper describes the structure and properties of the drug domperidone and a novel 1:1 domperidone succinate salt. The new salt is characterized by means of thermal, spectroscopic, microscopic and powder diffraction measurements. The crystal structures of the salt and, for the first time, of pure domperidone have been determined by means of single-crystal X-ray diffraction. In both structures, the piperidine ring of domperidone adopts the expected chair conformation, and supramolecular centrosymmetric R2(2)(8) motifs are formed by N-H...O hydrogen bonds between chlorine-substituted oxobenzimidazolyl groups. Further N-H...O hydrogen bonds occur between non-substituted oxobenzimidazolyl groups and the resulting C(4) motifs originates hydrogen-bonded chains, extending along the crystallographic b axis. In the salt, a single N-H...O hydrogen bond forms between the protonated nitrogen of the piperidine ring and the carboxylic O atom of the succinate ion. Two alternative and mutually exclusive positions for the nonsubstituted oxobenzimidazolyl group have also been observed; this disorder makes the hydrogen-bonded chains originating from the bicyclic group polar. The dissolution behaviour of the salt in dosage form is compared with two reference commercial products. The salt shows an increased solubility, a characteristic that could be of great advantage from a pharmaceutical view point.