Germanium Atoms Exceed the Tetrahedral Coordination in MFI Zeolite.

Germanium is known to occupy tetrahedral sites by substituting silicon in germanosilicate zeolites. In this study, we present pioneering findings regarding the synthesis of zeolites with an MFI structure (GeMFI) incorporating a high germanium amount (16% Ge). Remarkably, the germanium atoms feature a slight electron deficiency with respect to GeO, and the typical coordination number of 4, as usually reported for the germanosilicate zeolites, is exceeded, giving rise to Ge dimers in a double-bridge configuration.

Identification and quantification protocol of hazardous-metal bearing minerals: Ni in serpentinite rocks from Valmalenco (Sondrio, Central Alps, Northern Italy).

Serpentinite is a widespread rock type used worldwide as building material. Heavy metals like Ni in both the serpentinite products and serpentinite mining wastes pose potential environmental and health issues. This work devises an analytical protocol to identify and quantify the Ni speciation in the mineralogical matrix, through: i) bulk Ni quantification; ii) quantitative mineralogical and chemical analysis of each Ni-rich mineral; iii) comparison of bulk analysis results with the sum of each contribution from the Ni-rich minerals.

An insight into REEs recovery from spent fluorescent lamps: Evaluation of the affinity of an NH-13X zeolite towards Ce, La, Eu and Y.

The constantly increasing demand of Rare Earth Elements (REEs) made them to be part of the so-called "critical elements" indispensable for the energy transition. The monopoly of only a few countries, the so-called balance problem between demand and natural abundance, and the need to limit the environmental costs of their mining, stress the necessity of a recycling policy of these elements. Different methods have been tested for REEs recovery.

The beneficial role of nano-sized FeO entrapped in ultra-stable Y zeolite for the complete mineralization of phenol by heterogeneous photo-Fenton under solar light.

Highly efficient, separable, and stable magnetic iron-based-photocatalysts produced from ultra-stable Y (USY) zeolite were applied, for the first time, to the photo-Fenton removal of phenol under solar light. USY Zeolite with a Si/Al molar ratio of 385 was impregnated under vacuum with an aqueous solution of Fe ions and thermally treated (500-750 °C) in a reducing atmosphere. Three catalysts, Fe-USY500°C-2h, Fe-USY600°C-2h and Fe-USY750°C-2h, containing different amounts of reduced iron species entrapped in the zeolitic matrix, were obtained.

Ion exchange capacity of synthetic zeolite L: a promising way for cerium recovery.

The increasing rare earth elements' (REE) demand to meet the market request and the current political scenario show that it is essential to find good solutions to recover these elements from waste (both industrial and mining). Zeolites are microporous materials with high cation exchange capacity, up to now only little investigated for REE recycle. Here, we propose the use of NH-exchanged zeolite L for Ce recovery from a very diluted solution (0.

Amino acid encapsulation in zeolite MOR: Effect of spatial confinement.

In this study the absorption of glycine, α-alanine and β-alanine amino acids into the pores of the synthetic zeolite Na-mordenite was investigated with the aim of: (i) evaluating the effectiveness of the MOR framework type in amino acid adsorption ( vapor and aqueous loading); (ii) understanding the host-guest and guest-guest interactions to possibly design a tailor made material and a loading procedure able to maximize the amino acid adsorption; (iii) studying the effect of pressure on the adsorbed amino acids such as, for instance, possible amino acid condensation. The structural characterization, carried out with the combination of diffractometric and infrared spectroscopy analyses, shows that MOR can adsorb amino acids, which are found both in protonated/deprotonated (possibly also generating zwitterions) form. Vapor loading is ineffective for α-alanine, while it is effective in β-alanine and glycine adsorption, even if using different loading degrees.

CO capture on natural zeolite clinoptilolite: Effect of temperature and role of the adsorption sites.

In this study, the adsorption capacity of the low-cost zeolite clinoptilolite was investigated for capturing carbon dioxide (CO) emitted from industrial processes at moderate temperature. The CO adsorption capacity of clinoptilolite (a commercial natural zeolite) and ion-exchanged (with Na and Ca) clinoptilolite were tested under both dynamic (using a fixed-bed reactor operating with 10% vol. CO in N) and equilibrium conditions (measuring single component adsorption isotherms).

Energetic Performance of Pure Silica Zeolites under High-Pressure Intrusion of LiCl Aqueous Solutions: An Overview.

An overview of all the studies on high-pressure intrusion-extrusion of LiCl aqueous solutions in hydrophobic pure silica zeolites (zeosils) for absorption and storage of mechanical energy is presented. Operational principles of heterogeneous lyophobic systems and their possible applications in the domains of mechanical energy storage, absorption, and generation are described. The intrusion of LiCl aqueous solutions instead of water allows to considerably increase energetic performance of zeosil-based systems by a strong rise of intrusion pressure.

Structural interpretation of the energetic performances of a pure silica LTA-type zeolite.

The high pressure intrusion-extrusion process of different electrolyte aqueous solutions (NaCl and CaCl2, 2 M and 3 M) in a hydrophobic pure-silica LTA zeolite was investigated for energetic purposes by means of in situ X-ray powder diffraction, porosimeter tests, thermogravimetric analysis and NMR spectroscopy. The intrusion pressure of the saline solutions was proved to be higher than that of pure water, with the highest value measured for CaCl2, thus increasing the energetic performance of the system. The intrusion of NaCl solutions was irreversible (bumper behavior), whereas that of CaCl2 solutions is partially reversible (shock absorber behavior).

High-temperature behavior of natural ferrierite: In-situ synchrotron X-ray powder diffraction study.

In this paper, we report the results of the first study focused on the thermal stability and dehydration dynamics of the natural zeolite mineral ferrierite. A sample from Monastir, Sardinia [(NaKMgCaSr) (AlSi)O·17.86HO; = 19.

Preparation and Characterization of Magnetic and Porous Metal-Ceramic Nanocomposites from a Zeolite Precursor and Their Application for DNA Separation.

In this work, metal-ceramic nanocomposites were obtained through short (up to 2 h) thermal treatments at relatively moderate temperatures (750–800 °C) under a reducing atmosphere, using Fe-exchanged zeolite A as the precursor. The as-obtained materials were characterized by X-ray powder diffraction analysis, N2 adsorption at –196 °C, and highresolution transmission electron microscopy. The results of these analyses showed that the nanocomposites consisted of a dispersion of metallic Fe nanoparticles within a porous ceramic matrix, mainly based on amorphous silica and alumina.

Irreversible Conversion of a Water-Ethanol Solution into an Organized Two-Dimensional Network of Alternating Supramolecular Units in a Hydrophobic Zeolite under Pressure.

Turning disorder into organization is a key issue in science. By making use of X-ray powder diffraction and modeling studies, we show herein that high pressures in combination with the shape and space constraints of the hydrophobic all-silica zeolite ferrierite separate an ethanol-water liquid mixture into ethanol dimer wires and water tetramer squares. The confined supramolecular blocks alternate in a binary two-dimensional (2D) architecture that remains stable upon complete pressure release.

Pressure-induced penetration of guest molecules in high-silica zeolites: the case of mordenite.

A synthetic high-silica mordenite (HS-MOR) has been compressed in both non-penetrating (silicone oil, s.o.) and penetrating [methanol : ethanol : water (16 : 3 : 1) (m.

WO3 nanorolls self-assembled as thin films by hydrothermal synthesis.

We report a novel type of WO3 nanostructure, i.e. nanorolls obtained as a self-assembled thin film on a transparent conductive substrate.

High-pressure-induced structural changes, amorphization and molecule penetration in MFI microporous materials: a review.

This is a comparative study on the high-pressure behavior of microporous materials with an MFI framework type (i.e. natural mutinaite, ZSM-5 and the all-silica phase silicalite-1), based on in-situ experiments in which penetrating and non-penetrating pressure-transmitting media were used.

Non-invasive chemical and phase analysis of Roman bronze artefacts from Thamusida (Morocco).

A repertory of Roman military bronze equipment (1st- 3rd century AD) found at the archaeological site of Thamusida (Rabat, Morocco) was analysed by non-destructive X-ray fluorescence and time of flight neutron diffraction (ToF-ND). Most objects are made of leaded alloys, where copper is combined with tin and/or zinc and, in six cases, to arsenic as well. A mixed technology was employed, making a limited use of "pure" semi-finished materials if compared with the large utilization of recycled materials (brass and bronze).

Anxiolytic-like effects of nociceptin/orphanin FQ in the elevated plus maze and in the conditioned defensive burying test in rats.

Different reports suggest that nociceptin/orphanin FQ (N/OFQ) may have either anxiolytic- or anxiogenic-like effect in rodents. Since N/OFQ elicits hypolocomotion, which undergoes rapid tolerance, and hypolocomotion may be associated to emotional consequences, the present study was designed to investigate the effect of N/OFQ on anxiety after development of tolerance to its hypolocomotor effect. The effect of single or double intracerebroventricular (i.

Acute noise stress analgesia in relation to 5-HT2 and mu-opioid receptor changes in the frontal cortex of young mice.

A number of studies have reported that exposure to stress provoked behavioural changes, including analgesia, in rodents. Differences have been observed in these responses to different types of stress and a link between hormones and neurotransmitters proposed. We studied the effect of acute noise stress on nociception and the possible changes in the serotonergic and opioidergic systems in young mice of both sexes.

Effect of oral chronic isoflavones supplementation on male rat sexual performances and sexual hormone plasma levels.

The aim of our study was to evaluate how a chronic isoflavones oral supplementation could affect male rat sexual behavior in relationship to cause eventual change in plasma sexual hormone concentrations. Isoflavones were administered in the form of a standardized dry extract of soybeans. Three groups of 20 sexually experienced male rats were consecutively treated with saline 2 ml, or isoflavones 0.

[Cardiovascular risk factors in severely ill psychiatric patients].

The most recent European guidelines for coronary heart disease (CHD) prevention acknowledges that stress/anxiety and depression are independent risk factors for CHD. The Psychiatric Patients Health Status Study is a transversal study on the health condition of 1.590 serious psychiatric patients.

Panax notoginseng (Burk.) effects on fibrinogen and lipid plasma level in rats fed on a high-fat diet.

Several studies have shown that notoginsenoides improve diastolic function in hypertensive subjects, induce the fibrinolytic system in in vitro models and act as antiproliferative agents on vessel leiomyocytes. Our aim was to evaluate their effect on fibrinogen and lipid plasma levels compared with a well-known HMGCoA reductase inhibitor. Seventy Wistar male adult rats on a fat-enriched diet were treated orally with P.

Preprotachykinin A gene expression after administration of 3,4-methylene dioxymethamphetamine (Ecstasy).

This study tested the effects of 8 days of subchronic administration of 3,4-methylene dioxymethamphetamine (MDMA) (5 mg/kg b.w.) on preprotachykinin A mRNA levels in discrete rat brain regions.

Hexanic Maca extract improves rat sexual performance more effectively than methanolic and chloroformic Maca extracts.

Lepidium meyenii (Maca) is traditionally employed in the Andean region for its supposed properties in improving fertility. The aim of this study was to determine the effect of subacute oral administration of hexanic, methanolic and chloroformic extracts of Maca root on sexual performance in inexperienced male rats. The following sexual performance parameters were evaluated: 1st mount, 1st intromission, ejaculation and post-ejaculatory latencies, intercopulatory interval and copulatory efficacy.