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1
Daurenbek, M., e A. Bakibaev. "Study of the microstructure of the complex sulphide compound ZnIn". BULLETIN of the L.N. Gumilyov Eurasian National University. Chemistry. Geography. Ecology Series 132, n. 3 (2020): 61–72. http://dx.doi.org/10.32523/2616-6771-2020-132-3-61-72.
Testo completoAbstract (sommario):
Currently, the production of new inorganic materials based on the sulfides synthesis is a major and promising direction. This is due to the obvious society needs for highly sensitive, fast-acting as well as economically attractive materials for various science branches and technologies. Such materials include ZnIn sulfide which has already found various practical applications.This work describes the methods for synthesis of sulfide material. The synthesis of the indicated sulfide was carried out by the developed methods.The obtained material was analyzed on an energy dispersive spectrometer М.Ә. Дәуренбек, А.А. Бакибаев 72Quantax 70, which allows for X-ray mapping, line elemental analysis and multielement point analysis. The specific features of the material microstructure and a surface nature of its structural elements are revealed.The obtained results make possible to predict many physicochemical properties of complex sulfides compounds and to judge their changes under various influences. Knowledge about microstructure features of such material as well as understanding of complex processes that affect its properties is an indispensable condition for new materials creation based on complex sulfides
2
Temmel, C., B. Karlsson e N. G. Ingesten. "Quenching cracks in medium carbon steel initiated at manganese sulfide inclusions". HTM Journal of Heat Treatment and Materials 62, n. 5 (1 ottobre 2007): 236–42. http://dx.doi.org/10.1515/htm-2007-0009.
Testo completoAbstract (sommario):
Abstract Quench crack propensity has been investigated for two identical medium carbon steels (50CrMo4) which only differed in sulfur content. The standard variant of the material was affected by manganese sulfide inclusions whereas the low sulfur material was essentially free of sulfides. 80 mm, cylindrical test specimens were used. The test specimens had been cut out of cross rolled steel plates in which the manganese sulfide were flattened to discoid shape. The specimen orientation was in direction of principal deformation where the flattened sulfides were aligned with the test specimen axis. The largest sulfides reached lengths of 150 μm. Both materials were austenitized at 850 °C for 60 minutes, quenched in a salt-bath at 180 °C and immediately annealed at 425 °C for one hour. It turned out that the standard material developed quench cracks which initiated at manganese sulfide. No cracks could be found in the low sulfur material. Thermal and transformational stresses, which develop during quenching, aggravate the stress situation around the manganese sulfide and cause the cracking. The results are interpreted in fracture mechanical terms.
3
Poch, R. M., B. P. Thomas, R. W. Fitzpatrick e R. H. Merry. "Micromorphological evidence for mineral weathering pathways in a coastal acid sulfate soil sequence with Mediterranean-type climate, South Australia". Soil Research 47, n. 4 (2009): 403. http://dx.doi.org/10.1071/sr07015.
Testo completoAbstract (sommario):
Soil micromorphology, using light microscopy and scanning electron microscopy (SEM), was used to describe detailed soil morphological and compositional changes and determine mineral weathering pathways in acid sulfate soils (ASS) from the following 2 contrasting coastal environments in Barker Inlet, South Australia: (i) a tidal mangrove forest with sulfidic material at St Kilda, and (ii) a former supratidal samphire area at Gillman that was drained in 1954 causing sulfuric material to form from sulfidic material. Pyrite framboids and cubes were identified in sulfidic material from both sites and are associated with sapric and hemic materials. Gypsum crystals, interpreted as a product of sulfide oxidation, were observed to have formed in lenticular voids within organic matter in the tidal mangrove soils at St Kilda. Sulfide oxidation was extensive in the drained soil at Gillman, evidenced by the formation of iron oxyhydroxide pseudomorphs (goethite crystallites and framboids) after pyrite and jarosite, and of gypsum crystals. Gypsum crystals occur where a local source of calcium such as shells or calcareous sand is present. Sporadic oxidation episodes are indicated by the formation of iron oxide and jarosite coatings around coarse biogenic voids. These observations indicate that mineral transformation pathways are strongly influenced by soil physico-chemical characteristics (i.e. oxidation rate, Eh, pH, soil solution chemistry, mineralogy, and spatial distribution of sulfides). This information has been used to illustrate the interrelationships of pyrite, carbonate, gypsum, jarosite, and organic matter and help predict soil evolution under changing hydro-geochemical, redoximorphic, and thermal conditions in soils from coastal environments.
4
Harrison, Susan T. L., Alexander H. Hesketh, Robert P. van Hille e Jennifer L. Broadhurst. "Process Decisions Focused on the Prevention of AMD Formation on Beneficiating Sulfide Minerals". Advanced Materials Research 71-73 (maggio 2009): 685–88. http://dx.doi.org/10.4028/www.scientific.net/amr.71-73.685.
Testo completoAbstract (sommario):
Acid Mine Drainage (AMD) from voluminous sulfide-bearing wastes contributes to the environmental burden of mineral processing. To diminish burden and its time frame of risk, the disposal of sulfidic waste materials is re-examined through the valuable distinction between reactive or active gangue materials contributing to AMD generation and largely unreactive passive gangue. In an example process for disposal of tails from mineral sulfide beneficiation, a proof of concept is provided for inclusion of a non-selective sulfide float preceding or following selective separation of the desired mineral sulfide. The environmental benefit of subsequent reduction of sulfide in the tailings from 3.7 to 0.2% on AMD generation potential is quantified through a combination of methodologies including MPA, ANC, NAPP, NAG and microbial testing. Sulfide reduction from 4 to 1% reduces AMD generation. Further reduction below 1% S yields diminishing returns. The environmental benefit of separating ‘active’ and ‘passive’ gangue material prior to disposal is shown, and the reduced active gangue fraction determined through material balance.
5
Martins, Natalia Pires, Sumit Srivastava, Francisco Veiga Simão, He Niu, Priyadharshini Perumal, Ruben Snellings, Mirja Illikainen, Hilde Chambart e Guillaume Habert. "Exploring the Potential for Utilization of Medium and Highly Sulfidic Mine Tailings in Construction Materials: A Review". Sustainability 13, n. 21 (3 novembre 2021): 12150. http://dx.doi.org/10.3390/su132112150.
Testo completoAbstract (sommario):
Medium and highly sulfidic tailings are high-volume wastes that can lead to severe environmental damage if not properly managed. Due to the high content of sulfide minerals, these tailings can undergo weathering if put in contact with oxygen and water, generating acid mine drainage (AMD). The moderate-to-high sulfide content is also an important technical limitation for their implementation in the production of construction materials. This paper reviews the use of sulfidic tailings as raw material in construction products, with a focus on cement, concrete, and ceramics. When used as aggregates in concrete, this can lead to concrete degradation by internal sulfate attack. In building ceramics, their implementation without prior treatment is undesirable due to the formation of black reduction core, efflorescence, SOx emissions, and their associated costs. Moreover, their intrinsic low reactivity represents a barrier for their use as supplementary cementitious materials (SCMs) and as precursors for alkali-activated materials (AAMs). Nevertheless, the production of calcium sulfoaluminate (CSA) cement can be a suitable path for the valorization of medium and highly sulfidic tailings. Otherwise difficult to upcycle, sulfidic tailings could be used in the clinker raw meal as an alternative raw material. Not only the SO3 and SiO2-rich bulk material is incorporated into reactive clinker phases, but also some minor constituents in the tailings may contribute to the production of such low-CO2 cements at lower temperatures. Nevertheless, this valorization route remains poorly explored and demands further research.
6
Medennikov, O. A., e N. P. Shabelskaya. "Technology for processing phosphogypsum into a fluorescent dye based on calcium sulfide". Fine Chemical Technologies 17, n. 4 (30 settembre 2022): 357–68. http://dx.doi.org/10.32362/2410-6593-2022-17-4-357-368.
Testo completoAbstract (sommario):
Objectives. There is considerable economic demand for products obtained by processing phosphogypsum. In particular, calcium sulfide-based materials having luminescent properties are the object of intensive study due to the wide range of possibilities for their use. The alloying of the structure of calcium sulfide with cations of rare earth elements leads to the appearance of a glow having various colors. However, the high cost of such phosphorescent materials is due to the high chemical purity of the reagents required for their synthesis. The development of efficient methods for obtaining calcium sulfide-based luminescent materials from phosphogypsum is part of an integrated approach to solving the problem of synthesizing economically demanded materials from production waste.Methods. The synthesized materials were studied using X-ray phase analysis and scanning electron microscopy. Photos of the samples were taken under illumination with an incandescent lamp or a fluorescent ultraviolet lamp.Results. According to X-ray phase analysis, phosphogypsum is mainly comprised of calcium sulfate dihydrate and calcium sulfate hemihydrate. Heat treatment of a phosphogypsum sample at a temperature of 1073 K is accompanied by the formation of anhydrous calcium sulfate. In the presence of a reducing agent, a composite material is formed containing a phase of anhydrous calcium sulfate and calcium sulfide. Due to the calcium sulfide content, phosphogypsum has luminescent properties when heat-treated in the presence of various reducing agents, including activated carbon, wood charcoal, vegetable oil, citric acid, starch, and sucrose.Conclusions. Optimal technological conditions for obtaining a composite material exhibiting luminescent properties are revealed. The successful synthesis of phosphor from without nonpretreated phosphogypsum is demonstrated. Optimal technological conditions for obtaining a composite material exhibiting luminescent properties are as follows: heat treatment temperature is 1073–1173 K; isothermal holding time is 60 min; reducing agent quantity is 37–50% (mol). The study results are widely applicable to processing wastes obtained from large-scale chemical production involving the production of a highly demanded inorganic product.
7
Ward, Nicholas J., Leigh A. Sullivan e Richard T. Bush. "The response of partially oxidised acid sulfate soil materials to anoxia". Soil Research 42, n. 6 (2004): 515. http://dx.doi.org/10.1071/sr03111.
Testo completoAbstract (sommario):
Four acid sulfate soil (ASS) materials were subjected to anoxia after varying periods of oxidation to determine the geochemical response of these types of soils to flooding. The response of the partially oxidised ASS materials to the exclusion of oxygen was variable. The rate of sulfide oxidation, acidification, and the production of soluble oxidation products such as sulfate, iron, and aluminium generally decreased markedly when subjected to anoxia. However, especially in the highly acidic ASS materials (i.e. pH <3.5), sulfide oxidation and acidification generally continued (albeit at much slower rates), most probably due to oxidation by Fe3+. Rapid sulfide re-formation occurred in the peat ASS material that had been oxidised for 63 days, with 0.47% reduced inorganic sulfur (SCR) formed over 60 days of anoxia. This substantial sulfide re-formation was accompanied by only a slight increase in pH. Minimal sulfide re-formation occurred in 2 of the ASS materials when placed in anoxic conditions, most likely due to a lack of readily available organic matter in these materials. The results show that the imposition of anoxic conditions on partially oxidised ASS materials is generally effective in decreasing the rates of further sulfide oxidation, acidification, and the production of soluble sulfide oxidation products. Biogeochemical sulfide formation consumes acidity; however, sulfide re-formation was ineffective in reversing acidification under the conditions of this experiment. The results indicate that the treatment of sites containing actual ASS materials by management strategies relying on oxygen exclusion need to be accompanied by other strategies that include acidty neutralisation or containment.
8
Ward, Nicholas J., Leigh A. Sullivan e Richard T. Bush. "Sulfide oxidation and acidification of acid sulfate soil materials treated with CaCO3 and seawater-neutralised bauxite refinery residue". Soil Research 40, n. 6 (2002): 1057. http://dx.doi.org/10.1071/sr01119.
Testo completoAbstract (sommario):
Acid sulfate soil (ASS) materials that are subject to oxidation are often treated with neutralising agents to minimise the export of acidity that may result from pyrite oxidation. The effects of additions of both CaCO3 and seawater-neutralised bauxite refinery residue (SNBRR) on the oxidation of sulfides and acidification were assessed for 4 ASS materials using laboratory incubation experiments. As the application of sub-optimal rates of neutralising materials can occur for a variety of reasons, the effect of application rates were also examined. Two application rates were chosen; a sub-optimal rate [approximately 20% of the theoretical neutralising requirement (NR)] and an excessive application rate (>250% of the NR). There was minimal sulfide oxidation and no acidification after the addition of excess CaCO3 over the 180 days of incubation. The addition of excess SNBRR prevented acidification, but substantial sulfide oxidation still occurred. Following a brief initial increase in pH when sub-optimal rates of CaCO3 and SNBRR were applied, the treated ASS materials rapidly acidified. For three of the ASS materials the addition of sub-optimal amounts of CaCO3 had little impact on the rate of sulfide oxidation. However, for the other ASS material (a peat) both the rates of sulfide oxidation and acidification were accelerated by the addition of sub-optimal rates of CaCO3, resulting in higher soluble Fe and Al concentrations than in the untreated ASS materials. For some of the ASS materials, sub-optimal applications of SNBRR resulted in elevated soluble Al.
9
Ward, Nicholas J., Leigh A. Sullivan e Richard T. Bush. "Soil pH, oxygen availability, and the rate of sulfide oxidation in acid sulfate soil materials: implications for environmental hazard assessment". Soil Research 42, n. 6 (2004): 509. http://dx.doi.org/10.1071/sr03110.
Testo completoAbstract (sommario):
The potential environmental hazard of acid sulfate soil (ASS) materials is directly related to both the net acidity and the rate that actual acidity is released from these soil materials into the environment. While current environmental hazard assessment techniques for ASS materials are able to quantify the net acidity, they do not take account of differences in the rate of sulfide oxidation (the dominant source of actual acidity) and differences in the rate of acidification. In this study the rate of sulfide oxidation during incubation was examined for 4 ASS materials. The effect of pH and oxygen availability on the rate of sulfide oxidation was assessed. The ASS materials were incubated in: (i) gauze where oxygen diffusion was not restricted, and (ii) sealed 100-µm-thick plastic bags which greatly limited oxygen diffusion. When oxygen diffusion was not restricted, an accelerated oxidation of sulfide occurred when the pH decreased below pH 4.0. The accelerated rate of sulfide oxidation at such low pH did not occur when oxygen diffusion was limited. This study indicates that the initial pH of an ASS material is a useful additional indicator of the potential environmental hazard of an ASS material when oxygen is expected to be non-limiting, such as when ASS materials are excavated and stockpiled. The recommended action criteria need to be reassessed, as the data indicate that the current criteria are conservative for alkaline and neutral ASS materials, but should be lowered for all acidic ASS materials (i.e. pH <5.5) to 0.03% sulfide regardless of texture.
10
Puhakka, J. A., J. A. Rintala e P. Vuoriranta. "Influence of Sulfur Compounds on Biogas Production from Forest Industry Wastewater". Water Science and Technology 17, n. 1 (1 gennaio 1985): 281–88. http://dx.doi.org/10.2166/wst.1985.0023.
Testo completoAbstract (sommario):
Various inorganic sulfur compounds and lignosulfonate were studied with respect to their effect on biogas production from synthetic wastewater simulating sulfite evaporator condensate. The sulfur balance during the anaerobic degradation was also investigated. In biogas production assay tests municipal digester sludge was used as seed material. Differences in sulfur inhibition of methanogenesis between various oxidation states of inorganic sulfur were detected. Sulfate and sulfide in concentrations 100 mg S/l had no effect whereas sulfite, thiosulfate and dithionite caused a lag-period in biogas production. Reduced biogas production was observed even with the addition of 1000 mg S/l as SO=4, SO=3 and S2O=3. Dithionite was the most toxic compound investigated. Sodiumlignosulfonate in concentrations 5-15 g/l has a supplementary increase in biogas production. Inorganic sulfur compounds were partially reduced to sulfide in anaerobic conditions.
11
Yap, Pei Lay, Yow Loo Au Yoong, Muralithran G. Kutty, Olaf Timpe, Malte Behrens e Sharifah Bee Abdul Hamid. "Facile Remediation Method of Copper Sulfide by Nitrogen Pre-Treatment". Advanced Materials Research 361-363 (ottobre 2011): 1445–50. http://dx.doi.org/10.4028/www.scientific.net/amr.361-363.1445.
Testo completoAbstract (sommario):
The deactivation and destabilization of copper sulfide when exposed to an oxidizing environment has led to the economical concerns as this sulfidic material can be easily destroyed by a series of oxidation processes. A promising and effective remediation technique in limiting the contact between covellite (CuS) and oxygen has been developed using a simple, hassle-free, non-corrosive, and eco-friendly pre-treatment of nitrogen approach. This remediation technique is remarkably effective as various techniques such as powder XRD, EDX, elemental mapping, and TGA-MS analyses have confirmed that covellite prepared with the pre-treatment of nitrogen does not oxidize to any mixed phase compound. Meanwhile, the study also shows that covellite stored without the pre-treatment of nitrogen has transformed to a mixed phase of pentahydrate copper sulfate and covellite. Hence, this method can be practically exercised not only on covellite, but possibly on other metal sulfides which are prone to be attacked by oxygen and water molecules in oxidizing environment.
12
Saputra, Beny, Agus Sutanto, Mia Cholvistaria, Suprayitno Suprayitno e Nala Rahmawati. "IDENTIFIKASI BAKTERI PEREDUKSI SULFAT PADA KAWAH AIR PANAS NIRWANA SUOH LAMPUNG BARAT". BIOLOVA 2, n. 2 (30 agosto 2021): 122–27. http://dx.doi.org/10.24127/biolova.v2i2.1089.
Testo completoAbstract (sommario):
Abstrak: Bakteri pereduksi sulfat atau Sulfate-reducing bacteria (SRB) adalah jenis bakteri obligat anaerob kemolitrotof memanfaatkan donor electron H2. Kemampuan SRB mereduksi sulfat menjadi sulfida mampu mengendapkan logam toksik meliputi Cd, Cu, dan Zn sebagai logam sulfida. SRB memerlukan substrat organik seperti asam piruvat yang dihasilkan oleh aktivitas anaerob lainnya. Mekanisme SRB dalam melakukan reduksi sulfat, sulfat digunakan sebagai sumber energi sebagai akseptor elektron dan menggunakan sumber karbon (C) sebagai donor elekton dalam metabolisme dan bahan penyusun sel. Pada kondisi anaerob bahan organik akan berperan sebagai donor elektron. Pembentukan senyawa sulfida melalui proses reduksi yang ditandai oleh penambahan elektron dari bahan organik yang menyebabkan turunnya konsentrasi sulfat dan naiknya pH lingkungan. SRB pada kawah air panas nirwana ini hidup secara anaerob pada suhu lingkungan 600C - 1000C dengan pH 7,4 tingkat kekeruhan air cukup keruh dan kandungan air yang mengandung blerang dengan indikator bau seperti telur busuk dan lingkungan sekitar terdiri dari sedimen batu kapur.
Abstract : Sulfate-reducing bacteria (BPS) is a type of chemolithotroph obligate anaerobic bacteria that utilize H2 electron donors. The ability of BPS to reduce sulfate to sulfide is able to precipitate toxic metals including Cd, Cu, and Zn as metal sulfides. BPS requires organic substrates such as pyruvic acid which is produced by other anaerobic activities. The BPS mechanism in reducing sulfate, sulfate is used as an energy source as an electron acceptor and uses a carbon source (C) as an electron donor in metabolism and cell building material. Under anaerobic conditions, organic matter will act as an electron donor. The formation of sulfide compounds through a reduction process is characterized by the addition of electrons from organic matter which causes a decrease in sulfate concentration and an increase in environmental pH. BPS in this nirvana hot spring crater lives anaerobically at an environmental temperature of 600C - 1000C with a pH of 7.4 the level of turbidity of the water is quite cloudy and the water content contains sulfur with an indicator of smell like rotten eggs and the surrounding environment consists of limestone sediments
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Hellgren, Simon, Fredrik Engström e Lena Sundqvist Öqvist. "The Characterization of Residues Related to the Roasting– Leaching–Electrowinning Zinc Production Route for Further Metal Extraction". Metals 14, n. 1 (8 gennaio 2024): 73. http://dx.doi.org/10.3390/met14010073.
Testo completoAbstract (sommario):
Super-hot acid leach residue is generated during zinc production in the roasting–leaching–electrowinning route, where both primary and secondary resources are used as feed material. This residue may contain valuable metals, such as lead, zinc, and iron, as well as precious metals, such as gold and silver. Four materials, namely super-hot acid leach residue, a residue formed when super-hot acid leach residue is selectively leached for lead with triethylenetetramine, as well as flotation concentrate, and flotation tailings formed in a selective silver flotation process with super-hot acid leach residue as the feed material were characterized to obtain a deeper understanding of possible further metal extraction. These four materials were characterized for chemical composition, mineralogy, and mineral distribution via chemical analyses, X-ray diffraction, and energy-dispersive scanning electron microscopy, respectively. The scanning electron microscope images showed that the materials have large variations in particle size distribution and composition. The results showed that the main lead phase in super-hot acid leach residue is lead sulfate, whereas it is mostly converted to lead sulfide during the selective lead leaching of the super-hot acid leach residue. The remaining lead sulfate is found in a solid solution with barium sulfate. Extracting lead from super-hot acid leach residue via triethylenetetramine leaching resulted in increased concentrations of gold and silver by 41% and 42%, respectively. The identified silver phases in super-hot acid leach residue may correspond to silver sulfide, silver chloride, and elementary silver, where silver sulfide was the most commonly occurring silver phase. After leaching this selectively for lead with triethylenetetramine, similar silver phases were identified, but silver sulfide and silver chloride occurred to a similar extent. Additionally, silver copper sulfide was detected. The presence of different silver phases might pose a challenge to reaching high silver recovery during leaching as the optimum leaching conditions differ somewhat. Furthermore, elemental sulfur, with a tendency to coat gold and silver particle surfaces, which is indicated to be present in all materials except the silver flotation tailings, may hinder metal extraction.
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Shabelskaya, Nina P., Elena V. Vasilieva, Elena A. Yakovenko, Yulia S. Podkovyrina e Alina A. Skorynina. "FEATURES OF SYNTHESIS OF INORGANIC LUMINESCENT MATERIAL FROM PHOSPHOGYPSUM". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, n. 10 (8 settembre 2020): 46–52. http://dx.doi.org/10.6060/ivkkt.20206310.6235.
Testo completoAbstract (sommario):
The paper discusses technological methods for obtaining a luminescent material from phosphogypsum. The obtained materials were characterized using X-ray phase analysis, X-ray fluorescence analysis, and electron microscopy. The elemental composition of the samples was determined using a laboratory micro-fluorimeter. In the course of the study, the technological conditions for converting the main part of phosphogypsum into a luminescent material based on calcium sulfide were established. It is shown that the process of obtaining luminescent CaS consists of dehydration stages: the initial stage, carried out at a temperature of 373 K to remove physically bound water, and the final stage, at a temperature of 1073 K – to remove crystallization water, as well as the stage of phosphogypsum reduced at a temperature of 1173 K for 0.5 h. An environmentally friendly material-sucrose-is considered as a reducing agent. It is shown that in the case of changing the technological modes of reduction the luminescent material cannot be obtained. Conducting the reduction process at a temperature of 773 K is accompanied by obtaining a sample contaminated with products of incomplete decomposition of the organic component of the charge. In this case, the sample does not contain calcium sulfide. Under prolonged isothermal exposure at a temperature of 1173 K, repeated oxidation of samples with loss of luminescence ability was observed. Optimal technological modes for obtaining materials with phosphor properties are formulated. According to the results of X-ray phase analysis, samples that do not show luminescence capacity contain calcium sulfate as the main phase. Samples-phosphors consist of a mixture of calcium sulfate and sulfide. Results obtained open up wide opportunities for involving in the re-processing of production waste to obtain cheap products in demand.
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Patel, Ishverbhai, e Sneha Solanki. "XRD Studies of Synthesized Bi2S3Crystalline Materials". Acta Crystallographica Section A Foundations and Advances 70, a1 (5 agosto 2014): C508. http://dx.doi.org/10.1107/s2053273314094911.
Testo completoAbstract (sommario):
Bismuth sulfide preparation and its x-ray diffraction studies are reported in this paper. The author have synthesized Bi2Sx (x = 3.15, 3.45) compound material with different sulfur content by conventional high temperature solid state solvothermal reaction of bismuth and sulfur which conforms that the (121) preferred orientation with crystallite size ~30 nm and splitting of peaks due to orthorhombic structure matches well with the standard data and demonstrate good crystalline quality and structural homogeneity of synthesized powder.This paper also describes the synthesis and x-ray diffraction studies of bismuth sulfide powder via versatile precipitation technique . Bismuth sulfide powder was synthesized using thiourea and sodium dodecyl sulfate or in absence of any surfactant maintained at 800C for 12 h keeping pH of solution constant at 1.4. Synthesized powder was characterized by x-ray diffraction technique which indicates that surfactants play major role in synthesis of bismuth sulfide that conforms the crystallite size ~35 nm. The employed solid state solvothermal technique played an important role to progress the homogeneous reaction and preparation of pure and fine bismuth sulfide powder. The possible application of this material in photovoltaic devices is suggested.
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Wong, Vanessa N. L., Michael D. Cheetham, Richard T. Bush, Leigh A. Sullivan e Nicholas J. Ward. "Accumulation of sulfidic sediments in a channelised inland river system, southern Australia". Marine and Freshwater Research 67, n. 11 (2016): 1655. http://dx.doi.org/10.1071/mf15080.
Testo completoAbstract (sommario):
Accumulation of sulfidic sediments in freshwater environments is a relatively recent phenomenon and an emerging environmental issue. In the present study, benthic sediments along short (~250m) reaches of an inland freshwater river in south-eastern Australia were examined to determine the abundance and vertical distribution of fine-grained organic sulfidic sediments, identified by acid volatile sulfide (AVS) and chromium-reducible sulfur (SCR) contents. Sulfidic sediments (up to 404mmolkg–1 SCR) preferentially accumulated in zones immediately overlying coarse sandy bed material. Conversely, where bed material was clay or silt dominated, comparatively limited sulfidic sediment had accumulated (where AVS and SCR were not detected). This suggests that the hydraulic conductivity of the underlying bed material could play a role in the formation of sulfidic sediments and that the overlying water column is not the sole source of SO42–. Evidence suggests that accumulation of sulfidic materials occurred preferentially downstream of channel obstructions, such as submerged logs or in scour pools. However, sediment accumulation was not limited to lower-energy parts of the channel, as would be expected for fine-grained organic sediments. Evidence of reworking, burial or sulfide formation at depth highlights the dynamism of the system and its differences to many coastal systems where these sediments are commonly found.
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Northrup, Paul, Ryan Tappero, Timothy D. Glotch, George J. Flynn, Mehmet Yesiltas, Yoko Kebukawa, Leonard Flores, Marina E. Gemma e Gavin Piccione. "Chemistry in Retrieved Ryugu Asteroid Samples Revealed by Non-Invasive X-ray Microanalyses: Pink-Beam Fluorescence CT and Tender-Energy Absorption Spectroscopy". Geosciences 14, n. 4 (21 aprile 2024): 111. http://dx.doi.org/10.3390/geosciences14040111.
Testo completoAbstract (sommario):
The Hayabusa2 space mission recently retrieved 5.4 g of material from asteroid Ryugu, providing the first direct access to pristine material from a carbonaceous asteroid. This study employs a novel combination of non-invasive synchrotron X-ray techniques to examine microscale chemistry (elemental distributions and element-specific chemical speciation and local structure) inside Ryugu grains without physically cutting the samples. Manganese primarily occurs in carbonate: Mn-bearing dolomite with minor earlier ankerite. Iron sulfides present as large single grains and as smaller particles in the finer-grained matrix are both predominantly pyrrhotite. At the 5 μm scale, Fe sulfides do not show the mineralogical heterogeneity seen in many carbonaceous meteorites but exhibit some heterogeneous localized oxidation. Iron is present often as intergrowths of oxide and sulfide, indicating incomplete replacement. Trace selenium substitutes for S in pyrrhotite. Copper is present as Fe-poor Cu sulfide. These results demonstrate multiple episodes of fluid alteration on the parent body, including partial oxidation, and help constrain the sequence or evolution of fluids and processes that resulted in the current grain-scale mineralogical composition of Ryugu materials.
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Kabdasli, Isik, Olcay Tünay e Derin Orhon. "Sulfate removal from indigo dyeing textile wastewaters". Water Science and Technology 32, n. 12 (1 dicembre 1995): 21–27. http://dx.doi.org/10.2166/wst.1995.0451.
Testo completoAbstract (sommario):
Sulfate is an important parameter especially for discharges to sewer systems. The textile industry is a major source of sulfate. Some sulfate sources in the industry have material replacement alternatives. However in some sources, sulfate or species convertible to sulfate are the main materials. The indigo dyeing process involves sulfur species as main materials. In this study, indigo dyeing wastewaters which contain significant concentrations of oxidized and non-oxidized sulfur components are evaluated in terms of sulfate removal. The approach is a pretreatment at the source before being mixed with other wastewaters. The study is conducted in two steps. In the first step, conversion of species to either sulfide or sulfate is experimentally evaluated. While reduction to sulfide poses problems, oxidation of all species to sulfate is found to be applicable. In the second step sulfate precipitation using calcium, barium and lead is practiced. Calcium precipitation provides up to 30% sulfate removal and these results are supported with existing literature data. Barium sulfate and lead sulfate precipitation provided practically complete removal. Economical evaluation of alternative methods is also given.
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Shajehan, Muhammad Rasyid Shah, Nurul Munirah Zamberi, Nur Afiqah Farihah Zaki, Anees Abdul Aziz e Norhafizah Burham. "Simulation of Polyvinylidene Fluoride, Zinc Sulfide, and Cadmium Sulfide as Lead-Free Piezoelectric Material". Materials Science Forum 1055 (4 marzo 2022): 63–68. http://dx.doi.org/10.4028/p-w6029f.
Testo completoAbstract (sommario):
This paper presents a simulation of three different types of lead-free piezoelectric materials for energy harvesting. Polyvinylidene Fluoride (PVDF), Zinc Sulfide (ZnS), and Cadmium Sulfide (CdS) are simulated using COMSOL Multiphysics to evaluate the frequency response and electrical potential for each materials. The simulation consisted of two parts which is 3D block cantilever for simulating frequency response and total displacement. The second part is 2D block bimorph to simulate power generated by varying frequency responses. The simulated result for the first shows that frequency response for each materials is differents for ZnS, PVDF and CdS which 30.897 kHz, 8.517 kHz, and 22.118 kHz. For total displacement is 303 µm which same for each materials. Each material is simulated for various cantilever beam thicknesses ranging from 1-4 µm and result ZnS having the greatest frequency response. For 2D block bimorph model, the highest electric potential is 0.75 V at 60 Hz frequency for ZnS. Meanwhile for CdS and PVDF has less electric potential which 0.6 V and 0.4V at 60 Hz frequency response. For power disspation, ZnS generate 10% more power compare to CdS and PVDF. In the end of the paper, ZnS is excellent lead free material compared to CdS and PVDF in term of aforementioned parameter studied.
20
Ward, N. J., L. A. Sullivan, D. M. Fyfe, R. T. Bush e A. J. P. Ferguson. "The process of sulfide oxidation in some acid sulfate soil materials". Soil Research 42, n. 4 (2004): 449. http://dx.doi.org/10.1071/sr03135.
Testo completoAbstract (sommario):
The process of sulfide oxidation in acid sulfate soils (ASS) is complex, involving the formation of numerous oxidation products. In this study the sulfide oxidation process was examined in 2 ASS materials over a period of 36 days using laboratory incubation experiments. Both ASS materials experienced substantial sulfide oxidation and acidification during incubation. The oxidation of pyrite was the primary cause of acidification in these ASS materials. Although a decrease in magnetic susceptibility (χ) over the initial 4 days of incubation suggested the rapid oxidation of ferromagnetic iron monosulfide greigite (Fe3S4), the total acid volatile sulfur (SAV) fraction increased in concentration by an order of magnitude over the initial 8 days of incubation. Oxygen (O2) concentration profiles indicated the presence of anoxic conditions in the centre of the incubating materials even after 16 days of exposure to the atmosphere enabling SAV formation to occur. The oxidation of the SAV fraction did not result in substantial acidification. A large proportion of the water-soluble iron released by sulfide oxidation was precipitated as iron oxides and hydroxides. Sulfate (SO42–) was the dominant sulfur species produced from sulfide oxidation in both ASS materials, although water-soluble SO42– was a poor indicator of the extent of sulfide oxidation. The sulfoxyanion intermediates, thiosulfate (S2O32–) and tetrathionate (S4O62–), were detected only in the early stages of incubation, with minimal amounts being detected after the initial 4 days. The relative abundance of these 2 intermediate sulfur species appeared to be dependent on the soil pH, with S4O62– dominating S2O32– in the more acidic ASS material (i.e. pH <6) as has been observed in previous studies. The diminishing presence of sulfoxyanion intermediates as oxidation progressed was indicative that ferric ion (Fe3+) and bacterial catalysis were driving the oxidation processes. While these sulfoxyanion intermediates only constituted a small percentage of the reduced inorganic sulfur (RIS) fraction, they accounted for up to 9.3% of the total soluble sulfur fraction. Elemental sulfur (S0) was not an important sulfide oxidation product in the ASS materials examined in this study.
21
St. John, Thomas W. "Geotechnical characterization of sulfur species in UK Jurassic mudrocks". Quarterly Journal of Engineering Geology and Hydrogeology 53, n. 4 (26 febbraio 2020): 598–608. http://dx.doi.org/10.1144/qjegh2019-148.
Testo completoAbstract (sommario):
Weathering of pyritic mudrocks results in the oxidation of sulfides and generation of sulfates in concentrations potentially hazardous to civil engineering works. Geochemical and petrographic analyses undertaken on samples from sites underlain by the Kimmeridge Clay Formation and Oxford Clay Formation proved three distinct zones: an upper sulfur-leached zone, an intermediate weathered zone with sulfate-rich horizons and a lower relatively unweathered zone of low-sulfate, high-sulfide material. It was found that water-soluble sulfate and total potential sulfate may vary by up to 1500 mg SO42− l−1 and 8% SO42− respectively, over a depth interval of only 0.2 m. A targeted sampling strategy and ground aggressivity assessment approach can be applied to these formations based upon the sulfur species zones identified.
22
Malitch, K. N., I. Yu Badanina, N. G. Soloshenko e S. F. Sluzhenikin. "Copper and zinc isotopic variations in Ni-Cu-PGE ores of the Noril’sk Province (Russia)". LITHOSPHERE (Russia) 24, n. 2 (6 maggio 2024): 300–325. http://dx.doi.org/10.24930/1681-9004-2024-24-2-300-325.
Testo completoAbstract (sommario):
Research subject. Mineral assemblages of sulfides from massive and disseminated sulfide nickel-copper-platinum-group element (Ni-Cu-PGE) and low-sulfide PGE ores of the Noril’sk Province, which hosts the richest complex deposits of platinum-group metals, nickel, and copper. Aim. In order to identify sources of ore material and explore new forecasting approaches for Ni-Cu-PGE deposits, we study the Cu- and Zn isotopic compositions of sulfides from economic Kharaelakh and Noril’sk-1 intrusions containing unique and large sulphide Ni-Cu-PGE deposits (Oktyabr’sk and Noril’sk-1, respectively), subeconmic Zub-Marksheider and Vologochan intrusions containing small- to medium-size Ni-Cu-PGE deposits, and non-economic Nizhny Talnakh and Nizhny Noril’sk intrusions containing low grade disseminated Ni-Cu mineralization. Results. The analyzed samples are characterized by sulfide mineral assemblages, which contain mainly chalcopyrite, pyrrhotite, pentlandite, troilite, cubanite, and galena. Sulfide Ni-Cu-PGE ores of the Oktyabr’sk and Noril’sk-1 deposits, associated with economic intrusions (i.e., Kharaelakh and Noril’sk-1), demonstrate distinct δ65Cu values from –2.42 to –1.40‰ and from –0.33 to 0.60‰, respectively, which differ from the δ65Cu values for sulfides from other Ni-Cu-PGE deposits and ore occurrences of the Noril’sk Province (data comprise 36 analyses). We note that the Cu-isotopic composition for sulfide minerals of massive and disseminated ores from the Kharaelakh intrusion has similar “isotope-light” characteristics. The most pronounced shift towards “isotope-heavy” copper was found in the horizon of low-sulfide PGE ores of the Noril’sk-1 intrusion (δ65Cu = 0.51–0.60‰). The isotopic composition of Zn (δ66Zn) for the studied sulfide samples from economic, subeconomic, and non-economic intrusions, with the exception of one sample (0.73 ± 0.14‰), is characterized by similar “isotope-light” values (from –0.65 to –0.03‰). Conclusions. The revealed variations in the Cu- and Zn-isotopic composition in the studied sulfide assemblages from all types of ores reflect their primary characteristics; however, for the unique Oktyabr’sk Ni-Cu-PGE deposit, characterized by the most “isotopically light” composition of copper (δ65Cu = –1.9 ± 0.34‰), the possibility of assimilation of an external source of Cu during the formation of sulfide Ni-Cu-PGE ores cannot be excluded. The combined use of Cu and Zn isotopic parameters proved to be a weakly informative predictive indicator for the detection of high-grade sulfide ores, primarily due to the similarity of the Zn isotopic composition of the ore material in all investigated intrusions of the Noril’sk Province.
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Adelhelm, Philipp. "CuS as Unique Cathode Material for Li Solid-State Batteries: Properties, Reaction Mechanism and Tomography". ECS Meeting Abstracts MA2023-01, n. 6 (28 agosto 2023): 1074. http://dx.doi.org/10.1149/ma2023-0161074mtgabs.
Testo completoAbstract (sommario):
Copper sulfide (CuS) is a naturally occurring mineral that reacts with lithium via a conversion reaction to form Li2S and Cu. The theoretical energy density of the reaction is 961 Wh/kg, the theoretical cell voltage is 1.96 V. Among all the conversion reactions, copper sulfide shows a unique behavior as large, µm-sized copper crystallites are formed during discharge. Some years ago, it was shown that the reaction can proceed reversibly in suitable electrolytes.[1] This presentation will discuss the behavior of copper sulfide as a cathode material in solid state batteries. In this context, the low cell voltage allows the use of Li3PS4 as a solid electrolyte, which is a major advantage. Despite the large volume expansion (+74%), the material can be cycled in solid state batteries at high contents (70 wt%), again forming large copper crystallites.[2] The size of the crystallites allows the reaction to be studied by 3D X-ray tomography.[3] In addition to phase transformations, crack formation can also be observed. The latter is strongly pressure dependent and can be minimized by increasing the pressure. [1] Birte Jache, Boris Mogwitz, Franziska Klein, Philipp Adelhelm (2014) Copper sulfides for rechargeable lithium batteries: Linking cycling stability to electrolyte composition Journal of Power Sources 247: 703-711. [2] Aggunda L Santhosha, N Nazer, Raimund Koerver, Simon Randau, Felix H Richter, Dominik A Weber, Joern Kulisch, Torben Adermann, Jürgen Janek, Philipp Adelhelm (2020) Macroscopic displacement reaction of copper sulfide in lithium solid-state batteries Advanced Energy Materials 2002394: . [3] Zhenggang Zhang, Kang Dong, Katherine A Mazzio, André Hilger, Henning Markötter, Fabian Wilde, Tobias Heinemann, Ingo Manke, Philipp Adelhelm (2022) Phase Transformation and Microstructural Evolution of CuS Electrodes in Solid-State Batteries Probed by in-situ 3D X-ray Tomography Advanced Energy Materials 2203143. Figure 1
24
Mamiyev, Zamin, e Narmina O. Balayeva. "Metal Sulfide Photocatalysts for Hydrogen Generation: A Review of Recent Advances". Catalysts 12, n. 11 (27 ottobre 2022): 1316. http://dx.doi.org/10.3390/catal12111316.
Testo completoAbstract (sommario):
Metal-sulfide nanostructures have piqued the interest of researchers for decades due to their intriguing optoelectronic properties. Indeed, significant advances and improvements have been made in various fundamental aspects for cutting-edge applications, such as water splitting and hydrogen production. Furthermore, rising demand for low-dimensional materials due to lower material consumption and improved performance due to quantum size effects has spurred research on semiconducting metal sulfides. Consequently, size-controllable nanostructures with diverse morphologies have been fabricated and studied for potential applications. However, the photocatalytic hydrogen evolution rate is still limited mainly by fast recombination rate, poor solar energy utilization and lack of surface-active sites for H2 reduction. This review will highlight particularly recent findings in metal-sulfide-based photocatalysts for hydrogen evolution reactions, considering the swift development and excellent research in this field. Following a brief overview of fundamental properties, we will explore state-of-the-art strategies for enhancing H2 generation efficiencies over the pristine, heterostructured and co-catalayzed metal-sulfide photocatalysts.
25
Trebukhov, Sergey, Valeriy Volodin, Alina Nitsenko, Xeniya Linnik, Erkebulan Kilibayev, Olga Kolesnikova e Yury Liseitsev. "Dearsenation of Gold-Bearing Composite Concentrates without Forced Displacement in a Sublimator". Journal of Composites Science 7, n. 9 (11 settembre 2023): 378. http://dx.doi.org/10.3390/jcs7090378.
Testo completoAbstract (sommario):
The primary devices for extracting volatile components from dispersed materials in a vacuum are devices with the movement of raw materials by directed vibrations. During the analysis of the operation of such installations, some shortcomings were identified, due to the supply of heat flow to the processed raw material and the requirements for the choice of structural materials. In this article, the authors tested a heating method and a design of a sublimator with the supply of heat flow to the dispersed material by radiation from the heater. The sublimation zone is made in the form of a shaft formed by simple-shaped plates, the design and material of which involve the use of refractory and ceramic materials that are inert with respect to an aggressive vaporous sulfide medium. The movement of bulk material through the volume of the sublimator occurs due to rheological properties: sliding along inclined plates. Technological tests on the sublimation of arsenic sulfides from gravity and flotation composite concentrates of the Bakyrchik deposit (Kazakhstan) have shown the possibility of a high degree of sublimation of arsenic (more than 96–99%) while preserving precious metal composites in the sublimation residue and stable operation of equipment. Sublimation residues containing 0.14–0.30% As can be processed by known methods. The possibility of sufficiently complete removal of arsenic and its compounds from composite concentrates at a reduced pressure with the removal of the latter in the most environmentally friendly sulfide form has been established.
26
Li, Zhe, Shiguo Zhang, Ce Zhang, Kazuhide Ueno, Tomohiro Yasuda, Ryoichi Tatara, Kaoru Dokko e Masayoshi Watanabe. "One-pot pyrolysis of lithium sulfate and graphene nanoplatelet aggregates: in situ formed Li2S/graphene composite for lithium–sulfur batteries". Nanoscale 7, n. 34 (2015): 14385–92. http://dx.doi.org/10.1039/c5nr03201f.
Testo completo
27
Kumar, Prashant, Wandi Wahyudi, Abhinav Sharma, Youyou Yuan, George T. Harrison, Murali Gedda, Xuan Wei et al. "Bismuth-based mixed-anion compounds for anode materials in rechargeable batteries". Chemical Communications 58, n. 20 (2022): 3354–57. http://dx.doi.org/10.1039/d1cc06456h.
Testo completoAbstract (sommario):
Chemical composition control in ternary mixed-anion material bismuth sulfide iodide (Bi–S–I) is achieved by controlling the sulfide concentration. Synthesized BiSI and BiSI/Bi13S18I2 show promise as anode materials for lithium-ion batteries.
28
Álvarez, María Luisa, José Manuel Fidalgo, Gabriel Gascó e Ana Méndez. "Hydrometallurgical Recovery of Cu and Zn from a Complex Sulfide Mineral by Fe3+/H2SO4 Leaching in the Presence of Carbon-Based Materials". Metals 11, n. 2 (6 febbraio 2021): 286. http://dx.doi.org/10.3390/met11020286.
Testo completoAbstract (sommario):
Chalcopyrite, the main ore of copper, is refractory in sulfuric media with slow dissolution. The most commonly employed hydrometallurgical process for the oxidation of chalcopyrite and copper extraction is the sulfuric acid ferric sulfate system The main objective of the present work is to study the use of cheap carbon-based materials in the leaching of copper and zinc from a sulfide complex mineral from Iberian Pyrite Belt (IPB). The addition effect of commercial charcoal (VC) and two magnetic biochars (BM and HM) that were obtained by pyrolysis of biomass wastes was compared to that of commercial activated carbon (AC). The experimental results performed in this work have shown that the presence of carbon-based materials significantly influences the kinetics of chalcopyrite leaching in the sulfuric acid ferric sulfate media at 90 °C. The amount of copper and zinc extracted from IPB without the addition of carbon-based material was 63 and 72%, respectively. The highest amount of extracted zinc (>90%) was obtained with the addition of VC and AC in IPB/carbon-based material ratio of 1/0.25 w/w. Moreover, it is possible to recover more than 80% of copper with the addition of VC in a ratio 1/0.25 w/w. Moreover, an optimization of the properties of the carbon-based material for its potential application as catalyst in the leaching of metals from sulfide is necessary.
29
Cai, Yangbo, Chenyu Wu, Xiuzhen Wang e Wei Kong. "Bi-metal Sulfides Embedded in MOF-derived N-doped Carbon Polyhedral Nanocages for High-performance Lithium-ion Batteries". Journal of Physics: Conference Series 2473, n. 1 (1 aprile 2023): 012001. http://dx.doi.org/10.1088/1742-6596/2473/1/012001.
Testo completoAbstract (sommario):
Abstract The high rate and long life performance of the lithium ion batteries are affected by serious volume change and low conductivity of the active electrode material during the charging and discharging. Herein, bimetal sulfides embedded in N-doped carbon polyhedral nanocages (SnS@CoS@NCNTs) are successfully designed by employing porous metal-organic frameworks (MOFs) as precursors. Benefiting from the abundant active sites of metal sulfide, the catalytic properties of CoS, and the high conductivity of porous carbon, SnS@CoS@NCNTs electrode materials exhibit excellent performance. The electrode delivers the initial specific capacity of 1112 mA·h·g−1 and the remarkable capacity of nearly 440 mA·h·g−1 after 300 cycles in current density of 1 A·g−1, which may be caused by the synergistic effect of bimetal sulfides and N-doped carbon polyhedral nanocages to enhance the structural stability and ion/electron conductivity. This work provides a feasible method for constructing bimetal-sulfide/carbon composites with excellent electrochemical performance.
30
Nimchik, Alexey, Golibjon Pulatov, Farkhod Yusupov, Bekzod Haydarov e Asadjon Kambarov. "Use of acid gases in the production of sodium sulphide". E3S Web of Conferences 494 (2024): 02003. http://dx.doi.org/10.1051/e3sconf/202449402003.
Testo completoAbstract (sommario):
This study was conducted to check the possibility of hydrogen sulfide as a material to produce sodium sulphide. It is a harmful substance that is released during production in many industrial production processes. In laboratory and semi-industrial conditions, the possibility of producing hydrogen sulfide using associated acid gases from hydrocarbon production as raw materials has been established. The resulting purified hydrogen sulfide, absorbed by a solution of sodium hydroxide, is a promising raw material in the production of sodium sulfide. The experiments on the production of sodium sulfide from natural gas processing waste, which contains hydrogen sulfide, showed the promise of using the proposed method. A new method and technology for the production of sodium sulfide has been developed, while the cost of the resulting product has been reduced due to the available local cheap raw materials, widely used in the chemical and mining industries and the simplification of the technological scheme and equipment used. Due to the developed method for the production of Na2S, it is possible to utilize a large number of waste gases from hydrocarbon production, as a result of which both environmental problems of the regions are solved, and it is also possible to obtain a product with great economic profitability.
31
Dalhem, Krister, Stefan Mattbäck, Anton Boman e Peter Österholm. "A simplified distillation-based sulfur speciation method for sulfidic soil materials". Bulletin of the Geological Society of Finland 93, n. 1 (13 giugno 2021): 19–30. http://dx.doi.org/10.17741/bgsf/93.1.002.
Testo completoAbstract (sommario):
Speciation of inorganic sulfur species, mainly pyrite and metastable iron sulfides by operationally defined methods, is widely used for risk assessment of acid sulfate soils by quantifying the acidity producing elements, as well as for general characterisation of marine sediments and subaqueous soils. “Traditional” sulfur speciation methods commonly use highly specialised glassware which can be cumbersome for the operator, or, require long reaction times which limit the usability of the method. We present a simplified method which has a sufficiently low limit of detection (0.002%) and quantitation (0.006%) required for the analysis of sulfidic sulfur in acid sulfate soil materials. Commercially available sulfide reagents were used for determining reproducibility and the method was assessed on natural sulfidic soil materials, including fine to coarse grained soil materials as well as sulfide bearing peat, with a large variation of metastable sulfide and pyrite content.
32
Bell, KH. "Chlorosulfination of Aromatic Methyl Ethers with Thionyl Chloride". Australian Journal of Chemistry 38, n. 8 (1985): 1209. http://dx.doi.org/10.1071/ch9851209.
Testo completoAbstract (sommario):
Aromatic sulfinyl chlorides have been prepared in high yield by direct chlorosulfination of some aromatic ethers (1,3-dimethoxybenzene, 2- methyl- and 4-chloro-1,3-dimethoxybenzene, 1,2,3-trimethoxybenzene, 1- and 2-methoxynaphthalene, 1,5-, 1,7-, 2,6- and 2,7- dimethoxynaphthalene ) with thionyl chloride alone at or below room temperature. Under the same conditions, 1,4-dimethoxynaphthalene and 1,3-dimethoxy-5-methylbenzene yield chlorinated starting materials and sulfides. 1,3,5-Trimethoxybenzene yields chlorinated starting material, sulfide, and a chlorinated disulfide. Some other ethers (e.g. anisole, 1,2- and 1,4-dimethoxybenzene, 5-chloro-1,3-dimethoxybenzene) are unreactive under these conditions.
33
Peng, Jie, Yu Cheng Liu, Zhi Feng Yan, Bao Gang Wang, Fu Dong Lin, Jian Zhuang e Yun Hai Ma. "Research on the Performance Influence of Second Adhesive to Friction Materials". Applied Mechanics and Materials 461 (novembre 2013): 415–20. http://dx.doi.org/10.4028/www.scientific.net/amm.461.415.
Testo completoAbstract (sommario):
The friction materials have many species and they are being used widely, but people have higher requests to friction materials along with the development of technology. the friction material of this expermental optimization formula have the advantages of suitable and stable friction coefficient under high temperature, low wear rate, good restoration characteristics and so on. It can effcetively reduce heat fade of friction and wear under high temperature barking. fricton and wear performance of friction material with second adhesive is better than common preparation friction material , it has higher friction coefficient and lower wear rate, It was determined by physical chemical properities of tin and sulfer. while heating or wearing, the temperature of friction material reach melting temperature of tin, it will become molten state, and sulfer has strong oxidation, on the one hand, tin and sulfer occurred chemical reaction, generating sulfide, stannous (one sulfide tin),on the other hand, while the sulfer is being molten state, it will absorb some abrasive dust, at the same time of generating sulfide, abrasive dust will be adsorb and solidify to pits of friction surface, forming abrasive dust membrane, let the friction coefficient of sample become stable rapidly, reducing the wear rate of friction material.
34
Chen, Zhaoyang, Qing Ai, Jun Lou, Viktor G. Hadjiev, Yanliang Liang e Yan Yao. "Constructing Favorable Microstructures in Solid-State Organic Cathodes Via Mechanical Property Manipulation". ECS Meeting Abstracts MA2022-01, n. 4 (7 luglio 2022): 546. http://dx.doi.org/10.1149/ma2022-014546mtgabs.
Testo completoAbstract (sommario):
Organic electrode materials, due to their low environment footprint and high material-level specific capacities, have become competitive alternatives to inorganic materials for solid-state batteries (SSB) in recent years. Additionally, the soft nature of organic compounds ensures consistent and intimate contact with solid sulfide electrolytes during cycling, which is beneficial for battery longevity. However, the low-modulus organic materials and high-modulus sulfide electrolytes, upon mixing and compression, would form unfavorable composite microstructure where sulfide particles are encapsulated by organics and cannot form an efficient ion conduction path. This mismatch in mechanical property prevents a high fraction of organic compounds to be used in a solid-state cathode, limiting the energy density of organic solid-state batteries. Here we report the formation of favorable microstructures of organic cathodes by “softening” the sulfide electrolytes. Solvent treatment of the sulfide electrolyte Li6PS5Cl more than halves its modulus from 28.6 ± 8.5 GPa to 16.0 ± 1.6 GPa. Thermal gravimetric analysis, Raman spectroscopy, and X-ray diffraction were used to elucidate the evolution of the sulfide electrolyte during the softening and recovering process. The organic cathode formed by mixing organic materials with this softened electrolyte shows a favorable microstructure where the electrolyte forms a percolated domain. As a result, the utilization of an organic material, pyrene-4,5,9,10-tetraone (PTO), is increased by 133.6% and 90.8% compared with cells with a re-hardened and the pristine Li6PS5Cl, respectively. The mass fraction of PTO can be improved from 20 to 40wt% while maintaining high utilization (85.7%). Our exploration of softened electrolyte builds the correlation among structure, mechanical property, microstructure engineering and battery performance, and the strategy is applicable to other active materials with low modulus.
35
Harnanda, Suriandi, Ginting Jalu Kusuma, Abie Badhurahman e Rizky Syaputra. "The Effect of Fly Ash Ratio Addition as Layering Material Using Free Draining Column Leach Test Method on Laboratory Scale". EKSPLORIUM 44, n. 1 (29 maggio 2023): 41. http://dx.doi.org/10.55981/eksplorium.2023.6707.
Testo completoAbstract (sommario):
Acid mine drainage (AMD) is formed due to the oxidation of sulfide minerals in the presence of water and air. AMD already entering the environment can damage the aquatic ecosystem due to low pH and high dissolved metal concentrations. Efforts to prevent the formation of AMD are by regulating the stockpiling of materials containing sulfide or potential acid forming (PAF) with non-acid forming (NAF) to avoid oxidation reactions of sulfide minerals. The purpose of this study was to simulate the effect of adding fly ash ratio as a PAF rock coating material to the quality characteristics of leachate using the laboratory-scale free draining column leach test (FDCLT) method. Adding fly ash ratio as a layering material significantly affects the quality of the resulting leachate. This is due to the physical condition of the fly ash material, which cannot prevent the meeting of AMD-forming components.
36
Zhai, Zhongbiao, Yacong Yang, Yingchun Miao, Xiaolin Xu e Yaqin Wang. "Reduction Smelting Experiment of Copper Dross with Low Copper Content". Science of Advanced Materials 13, n. 12 (1 dicembre 2021): 2403–12. http://dx.doi.org/10.1166/sam.2021.4105.
Testo completoAbstract (sommario):
Copper dross with less copper content was used as raw material for reduction smelting experiment, and the effects of the amount of coke fines dosage, the reduction smelting temperature, and the reduction smelting time on the distribution of the main elements in the copper dross between the various layers were investigated by the bath smelting process during the reduction smelting process. The optimum experiment conditions were as follows: the number of coke fines was 0.1% of the mass of copper dross, the smelting temperature was 1250 °C, and the smelting time was 90 min. Under this condition, the medium frequency furnace was used to carry out the pilot experiment of copper dross, and the experiment results were similar to the laboratory results. Copper dross achieved the separation of valuable metals through reduction and smelting, and obtains four kinds of materials such as crude lead, matte, slag, and smoke dust. Metal lead, silver, and arsenic were mainly concentrated in the crude lead, sulfides such as lead sulfide, cuprous sulfide, and ferrous sulfide were mainly concentrated in matte copper, lead oxide, and slag-forming elements were mainly concentrated in slag, and lead oxide was mainly concentrated in smoke dust.
37
Heift, Dominikus. "Iron Sulfide Materials: Catalysts for Electrochemical Hydrogen Evolution". Inorganics 7, n. 6 (19 giugno 2019): 75. http://dx.doi.org/10.3390/inorganics7060075.
Testo completoAbstract (sommario):
The chemical challenge of economically splitting water into molecular hydrogen and oxygen requires continuous development of more efficient, less-toxic, and cheaper catalyst materials. This review article highlights the potential of iron sulfide-based nanomaterials as electrocatalysts for water-splitting and predominantly as catalysts for the hydrogen evolution reaction (HER). Besides new synthetic techniques leading to phase-pure iron sulfide nano objects and thin-films, the article reviews three new material classes: (a) FeS2-TiO2 hybrid structures; (b) iron sulfide-2D carbon support composites; and (c) metal-doped (e.g., cobalt and nickel) iron sulfide materials. In recent years, immense progress has been made in the development of these materials, which exhibit enormous potential as hydrogen evolution catalysts and may represent a genuine alternative to more traditional, noble metal-based catalysts. First developments in this comparably new research area are summarized in this article and discussed together with theoretical studies on hydrogen evolution reactions involving iron sulfide electrocatalysts.
38
Artemyev, Dmitry A., e Maksim N. Ankushev. "Trace Elements of Cu-(Fe)-Sulfide Inclusions in Bronze Age Copper Slags from South Urals and Kazakhstan: Ore Sources and Alloying Additions". Minerals 9, n. 12 (30 novembre 2019): 746. http://dx.doi.org/10.3390/min9120746.
Testo completoAbstract (sommario):
In the paper, the results of an investigation into trace elements found in slag sulfides from 14 archaeological Bronze Age settlements of the Cis-Urals, Trans-Urals, and North and Central Kazakhstan are presented. The study used Cu-(Fe)-sulfides as indicator minerals. Cu-(Fe)-S minerals in slags are primarily represented by covellite and chalcocite, as well as by rarer bornite and single chalcopyrite grains. Slag sulfides formed relic clasts and neogenic droplets of different shapes and sizes. Supergenic ores in the Bronze Age in Urals and Kazakhstan played a significant role in the mineralogical raw material base. In sulfides, the main indicator elements, Fe, Co, Ni, As, Se, Te, Sb, Ag, Pb, and Bi, are important markers of copper deposit types. Sulfides from olivine Cr-rich spinel containing slags of Ustye, Turganik are characterized by As-Co-Ni high contents and confined to copper deposits in ultramafic rocks. Olivine sulfide-containing slags from Kamenny Ambar, Konoplyanka and Sarlybay 3 are characterized by Co-Se-Te assemblage and confined to mafic rocks. Glassy sulfide-containing slags from Katzbakh 6, Turganik, Ordynsky Ovrag, Ivanovskoe, Tokskoe, Bulanovskoe 2, Kuzminkovskoe 2, Pokrovskoe, Rodnikovoe, and Taldysay are characterized by Ag-Pb-(Ba)-(Bi) assemblage and confined to cupriferous sandstone deposits. High As, Sb, Sn, and Ba contents found in slags can be seen as indicators of alloying or flux components in primary copper smelting. These include samples from Ustye, Katzbakh 6, Rodnikovoe, and Taldysay sites, where high Ba and As slag contents are identified. The compilation of a database with a broad sample of sulfide compositions from Bronze Age slags and mines in the Urals and Kazakhstan will permit the further identification of ore types and raw materials associated with a particular deposit.
39
Pillay, Keshree, Aubrey Njema Mainza, Deshenthree Chetty e Megan Becker. "Mineralogical Factors Affecting the Dense Medium Separation of Nickel Sulfide Ores". Minerals 12, n. 10 (18 ottobre 2022): 1311. http://dx.doi.org/10.3390/min12101311.
Testo completoAbstract (sommario):
Dense medium separation (DMS) is often used to reject a large portion of gangue material upfront to create cost and energy savings during processing. As lower-grade ores with complex mineralogy are being increasingly exploited, the properties of the gangue minerals begin to play a more important role in the upgrading of the ore. It is therefore important to understand these mineralogical factors to be able to select suitable processing routes for specific ore types. Two nickel sulfide deposits in southern Africa were chosen as case studies to understand differences in DMS efficiency when applied to different ores: Ore A and Ore B. Both ores showed nickel upgrades using DMS and the products were then characterized using QEMSCAN, with the aid of X-ray diffraction and electron probe microanalysis. Overall, particle density remains the main control on the separation, followed by sulfide texture, with massive and net-textured sulfides having larger grain sizes and therefore better liberation than disseminated sulfides. In addition to the concentration of sulfides, primary and secondary silicate minerals are separated by their density differences, which can affect the recovery of finely disseminated sulfides associated with them. Particle size is also important in DMS, with material near the cut-point density separating on size rather than density. The understanding of the mineralogical properties affecting DMS can aid in the prediction of the suitability of DMS for different ore types.
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Zinchenko, V. F., I. R. Magunov, O. V. Mozkova e B. A. Gorshtein. "The problem of oxide admixtures in zinc sulfide as a material for infrared optics (a review)". Voprosy Khimii i Khimicheskoi Tekhnologii, n. 3 (giugno 2023): 22–28. http://dx.doi.org/10.32434/0321-4095-2023-148-3-22-28.
Testo completoAbstract (sommario):
The paper reports on the main physicochemical properties of zinc sulfide (ZnS) and the features of its application in optics, optoelectronics, and semiconductor technology, as well as the main synthesis methods (synthesis in a solution, self-propagating high-temperature synthesis, and chemical vapor deposition). The harmful effect of the ZnO admixture on the optical and operational properties of zinc sulfide as a starting material for optical ceramics and in a thin film coating is shown. Possible ways of zinc oxide entering the base material during synthesis, storage in air or subsequent heat treatment are considered. The possibility of detecting and estimating the content of oxide admixture (ZnO) in ZnS by methods of substantial chemical analysis has been established. For the first time, approaches were proposed and implemented aimed at weakening the harmful effect of oxide admixtures by binding them with the help of lanthanide sulfides and sulfofluorides, followed by the formation of lanthanide oxosulfides by exchange reactions. The use of the addition of boron oxide (B2O3) with the formation of complex compounds with significantly lower chemical activity and volatility compared to ZnO is considered more promising. The method developed by the authors implies the complete removal of the ZnO impurity by heat treatment of the material with a sulfurizing agent, Sb2S3, the excess of which is removed by heat treatment in a vacuum. This method seems to be more labor-intensive, but more attractive for consumers of zinc sulfide as a material for interference optics.
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Sudha, K., R. Sasireka, T. Chitravel e T. P. Kumar. "Various Cu+, Mg2+ and S2- ionic concentration effects on a novel Cu2ZnMgS4 quaternary compound synthesis for various scientific applications". Journal of Ovonic Research 19, n. 6 (20 dicembre 2023): 793–808. http://dx.doi.org/10.15251/jor.2023.196.793.
Testo completoAbstract (sommario):
Copper zinc magnesium sulfide semiconducting material (Cu2ZnMgS4) compound is slightly new in electronics, opto-electronics and photo emissive field research. So that, we examined the Cu2ZnMgS4 compound formation characteristics step by step using the Copper sulfate (CuSO4.XH2O), Zinc sulfate (ZnSO4.XH2O), Magnesium sulfate (MgSO4.XH2O) and Sodium sulfide Na2S salt solutions. Characterizations such as pH, Electrical conductivity (EC), TDS were carried out for several concentrations. Further its optics properties of Cu2ZnMgS4 compound in liquid form were investigated through photo-colorimeter measurements (at various color λ including mixed band wavelengths), photo-fluorometer (using various primary and secondary filters) and UV-Vis spectrophotometer (at wavelength range of 300 to 900 nm) measurements. The investigated long term results are presented and discussed in this research article.
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Naberezhna, Olga. "ULTRASOUND RESEARCH OF THE INFLUENCE OF CARBON FIBERS ON THE PROPERTIES OF CARBON PLASTIC BASED ON POLYPHENYLENE SULPHIDE". Technical Sciences and Technologies, n. 2(28) (2022): 69–75. http://dx.doi.org/10.25140/2411-5363-2022-2(28)-69-75.
Testo completoAbstract (sommario):
Polyphenylene sulfides are one of the plastics with truly outstanding characteristics. The introduction of carbon fibers into the composition of the matrix contributes to the expansion of their potential use. The main requirement for the obtainedmaterialsis to increase their strength indicators due to the reinforcement of the matrix frame with carbon fibers.Carbon plastics are distinguished among other composite materials by high specific strength and stiffness, low coeffi-cients of linear thermal expansion and friction, high wear resistance and resistance to aggressive environments. This allows their use in defense industries and, above all, in aviation and rocket engineering.The analysis of the latest research and publications showed that the issue of selection and distribution of carbon fiber has a strong influence on the final indicators of the material's properties. To improve the operational characteristics, discrete carbon fibers were introduced into the composition of polyphenylene sulfide. The main goal of this method of obtaining com-posites was the uniform distribution of fibers in the polymer matrix.The article presents the results of mechanical tests of polyphenylene sulfide and carbon plastics based on it, the main indicators are determined: strength, relative deformation and modulus of elasticity, microhardness. It is shown that the method of acoustic defectoscopy -ultrasonic control can be used to assess the strength characteristics of compositions based on poly-phenylene sulfide. A non-destructive approach to the study of carbon plastics based on polyphenylene sulfide is proposed, which results correlate with laboratory studies of material properties. The pulses of the reflected "bottom" signals are given and the speed of wave propagation in the material is determined.The analysis of the physical and mechanical properties showed that the resulting carbon-plastics are characterized by fairly high strength indicators, which makes it possible to recommend them for replacing thermoplastic and thermosetting polymers, especially in machine building.
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Feng, Yuanjiao, Home Miao, Xue Zeng e Wenwu Zhong. "Research progress on preparation and anti-tumor application of copper sulfide nanocomposites: A review". Acta Poloniae Pharmaceutica - Drug Research 80, n. 1 (28 aprile 2023): 3–12. http://dx.doi.org/10.32383/appdr/157410.
Testo completoAbstract (sommario):
Photothermal diagnosis and treatment agents are more and more widely studied in cancer diagnosis and treatment. Copper sulfide nanocomposite is an economical and superior semiconductor material in photothermal diagnosis and treatment agents. At present, there are copper sulfide nanocomposites prepared by different materials and methods, and in-depth research has been done in the applications of cancer diagnosis and treatment, antibacterial, and biosensing. This article reviews the preparation of copper sulfide nanocomposites in recent years and their research progress in cancer diagnosis and treatment, and prospects for the future. It could provide a theoretical basis for the application and development of semiconductor materials in the clinical diagnosis and treatment of tumors.
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Davydov, S. Ya, e A. N. Semin. "Thermal enrichment of gold- bearing sulfide mineral material using centrifugal flotation". NOVYE OGNEUPORY (NEW REFRACTORIES), n. 9 (30 novembre 2023): 11–15. http://dx.doi.org/10.17073/1683-4518-2023-9-11-15.
Testo completoAbstract (sommario):
Depleted gold-containing sulfide mineral materials can be used in cement production, in the construction industry, in road construction and other sectors of the national economy. This will allow metallurgical enterprises to switch to low-waste or non-waste technology. Studies and practice of ore dressing with a high degree of sulfidity show that gold extraction is directly dependent on the degree of sulfidity of the ore and the content of the main ore sulfide minerals in it. To increase the efficiency of gold extraction, a device for enriching gold-containing sulfide materials using centrifugal flotation is proposed
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Kimpe, Christian De, e Norman Miles. "Formation of swelling clay minerals by sulfide oxidation in some metamorphic rocks and related soils of Ontario, Canada". Canadian Journal of Soil Science 72, n. 3 (1 agosto 1992): 263–70. http://dx.doi.org/10.4141/cjss92-025.
Testo completoAbstract (sommario):
Sulfide minerals are commonly present in the metamorphic and igneous rocks of southeastern Ontario. They are also dispersed in the till that is the parent material for many soils in the area. When sulfides from these rocks are exposed to a humid atmosphere, bacteria (Thiobacillus ferrooxidans) proliferate and acid sulfate weathering proceeds rapidly with the formation of jarosite, for which K+ ions are provided by the alteration of micas and feldspar. Interstratified minerals occur as an intermediate stage during the transformation of micas towards swelling clay minerals, which are major constituents of the clay-size fraction. A similar transformation likely takes place in the soils of the area, in which swelling clay minerals are dominant. This hypothesis may be further supported by the presence of large amounts of goethite, a weathering (hydrolysis) product of jarosite. Key words: Jarosite, goethite, smectite, vermiculite, acid sulfate weathering
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Yu, Haoran, Ding Shen, Ran Zhang e Shiyu Zhao. "Synthesis of Flower-like Crystal Nickel–Cobalt Sulfide and Its Supercapacitor Performance". Coatings 14, n. 5 (2 maggio 2024): 564. http://dx.doi.org/10.3390/coatings14050564.
Testo completoAbstract (sommario):
In order to improve the pseudocapacitance performance of metal sulfide electrode materials and obtain supercapacitor energy storage devices with excellent electrochemical reversibility and long-term cycle stability, the synthesis of flower-shaped crystal nickel–cobalt sulfide and its supercapacitor performance were studied. NiCo2S4 flower-shaped crystal nickel–cobalt sulfide was prepared by the hydrothermal method with nickel foam as the raw material, and electrode materials were added to prepare supercapacitor electrodes for testing of the supercapacitor performance. The physical properties of flower-shaped crystal nickel–cobalt sulfide were tested by a scanning electron microscope and transmission electron microscope, and the voltammetric cycle and constant current charge and discharge of supercapacitor electrodes prepared from this sulfide were analyzed through experiments. The experimental results showed that the flower crystal microstructure had a positive effect on the electrochemical properties. The capacitance value was always high at different current densities, and the capacity was as high as 3867.8 A/g at pH 12. After 2000 voltage–charge–discharge cycle tests, the petal-like sulfide capacity still had a retention rate of 90.57, the flower crystal nickel–cobalt sulfide still showed an excellent supercapacitor performance and the specific capacity was still high, which demonstrates that this sulfide has excellent cyclic stability and durability in electrochemical applications.
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Shcheglov, P. A., D. A. Samsonov, A. B. Pavlenkov, Yu M. Sidorov e A. V. Samoryadov. "Application of innovative polymer composite materials based on polyphenylene sulfide in the design of power supply devices". Plasticheskie massy, n. 3-4 (23 maggio 2023): 39–43. http://dx.doi.org/10.35164/0554-2901-2023-3-4-39-43.
Testo completoAbstract (sommario):
Russian glass-filled materials based on polyphenylene sulfide were used for the first time as a structural material of parts of miniature power supply devices based on stand-by chemical current sources. The advantages of these materials over traditional press materials are shown, the main of which are increased structural strength, reduced defectiveness of parts, reduced number of rejects, improved technical and economic production indicators. The application of polyphenylene sulfide-based materials allowed developing of power sources possessing unprecedented short activation time and building the high-tech industrial production of power supply devices.
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Yokogawa, Yoshiyuki, Yutaro Yagi, Hroya Sano, Atsutomo Nakamura e Ippei Kishida. "The VSC Adsorption on Hydrotalcite through Topochemical Reactions". Key Engineering Materials 529-530 (novembre 2012): 650–53. http://dx.doi.org/10.4028/www.scientific.net/kem.529-530.650.
Testo completoAbstract (sommario):
Volatile sulfur compounds (VSCs) such as hydrogen sulfide (H2S), methyl mercaptan and dimethyl sulfide produced in mouth. Some oral (Gram-negative) bacteria produce VSCs, which induces permeability of mucous membrane, cause the oral malordor, dental caries, color change of the dental fillings. Thus, material which adsorbs VSCs should be useful to keep health in mouth. Previously, we reported the H2S adsorptive properties of zeolite and hydrotalcite materials having micro pores. The amount of H2S adsorbed on the zeolite or hydrotalcite at room temperature was found to be around 300-400 ppm, and and 3 % of H2S was desorbed when heated at 400 °C. The hydrotalcite, whose compositon is Mg1-xAlx(OH)2Ax/n·mH2O, where A is CO32-, and x is 0.25, was heat-treated at 500 °C, and put into aqueous solution containing H2S. In this study, the relation between heat-treatment tempearture and the sulfide adsorption on hydrotalcite in aqueous solution was investigated. The hydrotalcite materials were hydrothermally synthesized and identified by powder X-ray diffraction method. The change in concentrations of H2S in aqueous solution was measured using FPD gas chromatography (GC). The concentrations of H2S was decreased with time for the hydrotalcite heated at 500 °C or 600 °C, and fell to 20 % for 12 hours. But, the concentration was decreased by 40% for 12 hours for the hydrotalcite materials heated at higher temperatue. XRD and FT-IR analysis revealed that the sulfides were into or out of the hydrotalcite structure through topochemical reactions.
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Ergashboy, Abdurakhmanov, Begmatov Rizamat e Abdurakhmanov Ilkhom. "Gas-Sensitive Material for Semiconductor Hydrogen Sulfide Sensor". Pakistan Journal of Analytical & Environmental Chemistry 24, n. 2 (22 dicembre 2023): 125–34. http://dx.doi.org/10.21743/pjaec/2023.12.01.
Testo completoAbstract (sommario):
In this work, the synthesis of porous silica gas-sensitive materials for semiconductor sensors of hydrogen sulfide is presented. As a result of studying the activity and selectivity of individual and binary oxides in the oxidation of combustible gases, the composition of the catalyst (10CuO + 90WO3) for the gas-sensitive element of the H2S sensor was selected. The selected catalysts ensure high semiconductor sensor (SCS) selectivity in a wide range of temperatures and H2S concentrations. The optimal ratio of the initial components for the synthesis of silica gas-sensitive materials for a semiconductor hydrogen sulfide sensor has been selected. It has been established that the period of maturation of the film-forming solution based on tetraethoxysilane (TEOS) is 6.5 hours, the period that ensures the production of gas-sensitive films is 18.5 days, and the aging period is 3.5 days. It was found that an increase in the process temperature from 20 to 40°C with a slight change in the viscosity of the solution leads to a sharp reduction in the stability time of the solution from 18.5 to 7.5 days.
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Sánchez-Fuente, Miguel, Alicia Jimenez-Almarza, José Alemán e Rubén Mas-Ballesté. "Solvent-Free Visible Light Photocatalytic Oxidation Processes Mediated by Transparent Films of an Imine-Based Organic Polymer". Catalysts 11, n. 12 (24 novembre 2021): 1426. http://dx.doi.org/10.3390/catal11121426.
Testo completoAbstract (sommario):
Reaction between concentrated solutions of phenotiazine containing trialdehyde building block 4,4′,4″-(10-phenothiazine-3,7,10-triyl)tribenzaldehyde and (1R,2R)-cyclohexane-1,2-diamine results in the formation of a yellow transparent film. Exhaustive characterization of this material indicates that it is the result of the assembly of a linear polymer resulting from the linking of imine-based macrocycles. Phenotiazine units confer to this plastic the optical properties characteristic of photocatalytic materials. The transparency of the obtained material enabled the performance of solvent-free photocatalytic processes. This concept is illustrated by the oxidation of liquid organic sulfides, which can be performed in a recyclable manner. According to selective quenching experiments, such processes are the result of the energy transfer to oxygen molecule, generating singlet oxygen that is able to activate the sulfide molecules directly.