Sulfur Crystals Research Articles

Disturbed lands objects use for the formation of technical universities students’ ecological culture (for example quarries sulfur deposits «Vodinskoe» in the Samara Region)

The following article deals with the problem of technical college students ecological culture formation on the example of disturbed lands objects study. The authors describe the features of pedagogical conditions that are necessary for creation of responsible personality attitude to the surrounding environment. The authors also analyze methods allowing to develop and create students valuable relation to the surrounding environment. Vodinsky sulfur pit near the settlement of Novosemeykino of the Krasnoyarsk district of the Samara region was used as an object of the disturbed lands. The uniqueness of this deposit is that the biggest sulfur crystal in the world was found here. Now, besides large sulfur crystals, crystals of other minerals - a tselestin, plaster, calcite, pyrites are also found here. The paper studies the possibility of one of the available fulfilled pits allocation as a standard of a natural mineralogical museum and especially protected natural territory in the region. The paper contains an analysis of fulfilled pits structure and location and their recultivation features. The authors consider the researched territory possible influence on its modern use. This kind of object will allow future engineers to understand a geoecological situation on Earth that will help to expand the knowledge of ecological culture.

Self-assembly of amorphous sulphur in bitumen–sulphur mixtures and its impact on properties

The inclusion of elemental sulphur in asphalt mixtures imparts an increased stiffness to the resultant asphalt pavements i.e. sulphur extended asphalt mixtures (SEAM), increasing the pavement performance. In the past, studies have been conducted which have attributed the increase in asphalt mixture stiffness to the formation of sulphur crystals in the voids of the compacted asphalt mixture. However, there are a limited number of studies which have investigated the influence of sulphur on the bitumen–sulphur mixture. This study investigates the fate of elemental sulphur in a bitumen–sulphur mixture over time and the impact of the sulphur to properties of the bitumen–sulphur mixture. It was seen that the sulphur added to bitumen could dissolve in the bitumen, exist as an amorphous phase or a crystalline phase, depending on the concentration of elemental sulphur present in the mixture. The stiffness of the bitumen–sulphur mixture was seen to increase with time, above a threshold sulphur concentration. This increase in the stiffness of the bitumen–sulphur mixture could be attributed to the observed aggregation of the amorphous sulphur over time. These findings provide an alternative theory to explain the increase stiffness of asphalt pavements containing SEAM.

Monoclinic sulfur cathode utilizing carbon for high-performance lithium–sulfur batteries

Abstract Sulfur cathodes for lithium–sulfur batteries have been designed to be combined with conductive carbon because the insulating nature of sulfur causes low active material utilization and poor rate capability. This paper is the first to report that carbon can induce a phase transition in a sulfur cathode. The stable form of a sulfur crystal at ambient temperature is orthorhombic sulfur. We found that monoclinic sulfur becomes more stable than orthorhombic sulfur if carbon atoms penetrate into the sulfur at elevated temperatures and the carbon density exceeds a threshold of C 0.3 S 8 . The high stability of the carbon-containing monoclinic sulfur persists during lithiation and is attributed to locally formed linear SC 3 S chains with marked stability. This study provides a novel perspective on the role of carbon in the sulfur cathode and suggests control of the crystal phase of electrodes by composite elements as a new way of designing efficient electrode materials.

Methodology of Nanomodified Binder Examination: Experimental and Numerical <i>Ab Initio</i> Studies

Feasibility of the sulfur-based construction materials is caused by properties, availability and low cost of sulfur. There exist numerous ways to improve the operational properties, including the ways that are based on nanotechnology, and ab initio (quantum chemistry) studies. Unfortunately, both application and verification of numerical simulation within the same research are quite complex. In the present case study we present typical scheme of survey involving both experimental and numerical studies. As a test subject we have selected orthorhombic sulfur crystals grown from the solution in toluene. It was clearly shown that good correspondence between experimental and numerical results can be achieved for offered methodology; Raman shifts for isolated S8 molecule mostly correspond to the shifts of sulfur crystal. Computed frequencies for all primary modes are close to the experimental data. Similar correspondences can serve as proofs of conformity between unknown molecular structures in nanomodified sulfur-based material and selected structural models

Abiotic interaction between hydrogen sulphide and cementitious materials

Concrete deterioration is extensively observed due to hydrogen sulphide emission in sewerage networks. The presence of this gas leads to the development of sulphur-oxidizing bacteria which produce sulphuric acid. Local deterioration of concrete sewer pipes, based on dissolution-precipitation mechanisms and the formation of ettringite and gypsum, degrades their mechanical properties and prevents optimum waste water collection. Due to expensive rehabilitation works, innovative sewerage network construction or repair approaches must be established and evaluated. The main final objective of this study is to put forward a representative, quick and standardized test and to develop a predictive model for the service life of different types of concrete in the environment of sewer pipes. This study focuses on interaction between cementitious materials and hydrogen sulphide (H 2 S) which is the first step of the degradation mechanism. Mortars based on different types of cement (CEM I, CEM IV and CAC) were exposed to H 2 S under various conditions (relative humidity, pre-exposure to H 2 S or otherwise). Changes in the H 2 S concentration were monitored as a function of time and the H 2 S adsorption rate was calculated. After 6 months of exposure, the state of deterioration of mortars was assessed. Some gypsum crystals on mortar surfaces based on CEM I and CAC cements and a mix of elemental sulphur and gypsum crystals on mortar surfaces based on CEM IV cement were observed by SEM-EDS. The decrease in the H 2 S adsorption rate, highlighted when the relative humidity decreased and when gypsum was present, must be taken into account in the modelling process.

Multidimensional operando analysis of macroscopic structure evolution in lithium sulfur cells by X-ray radiography.

Lithium sulfur cells are the most promising candidate for the post lithium-ion battery era. Their major drawback is rapid capacity fading attributed to the complex electrochemical processes during charge and discharge which are not known precisely. Here we present for the first time a multidimensional operando measurement by combining X-ray radiography with impedance spectroscopy while galvanostatically charging and discharging a lithium sulfur cell. The formation of macroscopic sulfur crystals at the end of charge can be seen directly by X-ray radiography. These crystals can be assigned to stable α-sulfur (rhombic) and metastable β-sulfur (monoclinic) by their characteristic crystal habit. These crystal structures with a length of more than 1 mm form and dissolve rapidly during cycling. Their appearance is accompanied by characteristic signals in impedance spectroscopy. Macroscopic crystals of Li2S cannot be observed in full agreement with earlier studies by operando X-ray diffraction. In addition, X-ray radiography reveals non-wetted areas on the carbon cathode. These regions grow during discharge and are reduced during charge. The area of these electrochemically inactive spots is inversely proportional to discharge capacity.

Dispersion properties of sulfur doped gallium selenide crystals studied by THz TDS.

High optical quality nonlinear crystals of solid solution GaSe(1-x)S(x), x=0, 0.05, 0.11, 0.22, 0.29, 0.44, 1 were grown by modified Bridgman method with heat field rotation. Ordinary and extraordinary wave dispersion was studied in detail as a function of sulfur content by terahertz time-domain spectroscopy (THz TDS) in the 0.3-4 THz range using cleaved and processed (cut and polished) crystals. Suitable dispersion equations for different parts of the entire transparency range were derived, utilizing comparative analyses of the measured data, the available published data, and approximations in the form of Sellmeier equations. A criterion was proposed for selecting measurement results of adequate quality, based on the etalon patterns in the transmission spectrum.

Composition and Genesis of the Nickel-Chrome-Bearing Nontronite and Montmorillonite in Lateritized Ultramafic Rocks in the Muratdği Region (Uşak, Western Anatolia), Turkey

AbstractWidespread lateritized ultramafic rocks in the southern part of the Muratdağı region of Turkey constitute a significant source of Ni-Cr-bearing ore with economic potential. However, no mineralogical or geochemical characterizations of these important materials have been performed previously. The aim of the present study was to describe the mineralogy, geochemistry, and genesis of Ni-Cr-bearing smectite in garnierite and ferruginous saprolite associated with the lateritized ophiolite-related ultramafic rocks. The lateritic zones are well developed over serpentinized harzburgitic mantle peridotites. The lateritized units and related bedrocks were examined using polarized-light microscopy, X-ray diffraction, scanning and transmission electron microscopies, and chemical and isotopic methods. The garnierite-containing saprolites are enriched in smectite, Fe-(oxyhydr)oxide phases, and opal-CT. Micromorphological images revealed that flaky smectite and, locally, Fe-rich particles, alunite, gypsum, gibbsite, and sulfur crystals developed along the fractures and dissolution voids. The development of saprolite demonstrates chemical weathering. The presence of silicified and Fe-(oxyhydr)oxide phases associated with gypsum, alunite, and local native sulfur in vertical and/or subvertical fractures and fault infillings are indicative of hydrothermal processes along the extensional, tectonically related fault systems. Chemical weathering and hydrothermal processes, which probably started during the Oligocene and Miocene, led to the formation of nontronite, Fe-bearing montmorillonite, and local Fe-rich kaolinite. Nickel and Cr are concentrated significantly in the saprolite zone and are positively correlated with Fe2O3 content, which is controlled by the formation of nontronite, montmorillonite, and Fe-(oxyhydr)oxide phases. Nickel-Cr-bearing nontronite and montmorillonite precipitated from alkaline water as a result of the increasing (Fe2O3+Al2O3+Cr2O5+Ni+Co)/(MgO+SiO2) ratio under the control of both chemical weathering and hydrothermal processes. The Fe and Mg (associated with Ni and Cr) required for the formation of smectite were supplied by solutions from both chemical weathering and hydrothermal alteration of Ni-Cr-bearing olivine and pyroxene in the harzburgitic bedrock; the Al was supplied by schists, granite, and volcanic units.

Nearshore euxinia in the photic zone of an ancient sea

Abstract Evidence for photic zone euxinia (PZE) in ancient oceans is widespread and commonly associated with global climate change and biotic events. However, evidence of PZE in marginal settings is commonly extrapolated to infer basin-scale characteristics. To explore the relationship between euxinia in marginal settings and the wider basin in one Palaeozoic context, we have conducted a detailed spatial and temporal examination the palaeowater-column redox state from the Polish sector of the Southern Permian Basin (SPB) during deposition of the Zechstein (Lopingian) second carbonate (Main Dolomite) cycle. Sediments from toe-of-slope, slope and hypersaline lagoonal settings of the northeastern margin of the SPB contain abundant chlorobactane, isorenieratane and their likely degradation products (C 15 to C 31 2,3,6-aryl isoprenoids). These indicate that part of the photic zone was euxinic during significant intervals of the Main Dolomite deposition. Further evidence for strongly anoxic conditions includes the occurrence of C 28 -bisnorhopane, high concentrations of pentakishomohopanes (i.e. high homohopane indices), and the occurrence of framboidal and native sulphur crystals in slope facies. However, a lack of these signatures in basinal settings indicates that strongly reducing conditions were restricted to the slope, and toe-of-slope locations. Even in these settings, however, highly variable homohopane indices and concentrations of isorenieratene and chlorobactene derivatives, as well as the presence of benthic fauna and bioturbation, indicate that anoxia fluctuated throughout deposition of the Main Dolomite, likely on a variety of timescales. Sterane distributions are also variable, suggesting a dynamic ecosystem, likely exhibiting a strong response to environmental forcing. Overall, it appears that high but episodic primary bioproductivity of organic matter was concentrated on the northeastern slope and restricted lagoons leading to the formation of source rocks for petroleum; however, the temporal and geographical restriction of anoxia appears to have prevented the accumulation of large or more widespread quantities of organic matter, and in fact TOC contents exhibit poor correlation with ecological and anoxia indicators. This model indicates that strong evidence for PZE in shelf and slope facies need not be associated with widespread, basin-scale anoxia, with implications for organic matter burial, carbon cycling and biotic crises.

Studies on sulfur doping and figure of merit in vapor grown Sb2Te3 platelet crystals

A series of p-type Sb2Te3−xSx (x=0, 0.1, 0.2, 0.3 and 0.4) samples for each sulfur composition was vapor deposited to explore the crystal growth mechanism of platelet morphology and to understand their potential use for thermoelectric devices. Structural characterization performed by X-ray diffraction exhibited consistent rhombohedral unit cell parameters for all the antimony telluride crystals with D53d space group symmetry. Scanning electron microscopy (SEM) and energy dispersive analysis by X-rays (EDAX) were employed for morphological and compositional studies. The Seebeck coefficient S (⊥c) of Sb2Te3−xSx crystals for sulfur composition, x=0.3 was remarkably improved, yielding a figure of merit (ZT)=0.54, which is ~2.5 fold rise compared to the melt grown Sb2Te3 crystals. The atomic force microscopic (AFM) imprints revealed that, with increasing content of dopant, distribution of etch pits and microhardness increased in sulfur doped crystals. By optimizing sulfur doping, the antisite (AS) defect formation can be suppressed for enhancing ZT and the results obtained enable to design novel thermoelectric materials for application in power generation and refrigeration.

Absorption anisotropy in sulfur doped gallium selenide crystals studied by THz-TDS

Abstract: Top optical quality nonlinear gallium selenide crystals doped with different sulfur concentrations (1.1, 2.5, 5, 7, 11 mass%) are grown by modified Bridgman method. Physical origins of inaccuracy in the measurement of THz o- and e-wave absorption spectra by THz-TDS are identified. Dominant absorption for o-wave is established for all crystal compositions. Frequency independent absorption within 0.3-2 THz is demonstrated. Phonon mode transformation is studied in detail. Phonon absorption peak for e-wave centered at 1.1 THz is recorded for the first time. It is shown that e-wave THz generation is preferable in GaSe:S (2.5-5 mass%) crystal.

Symbiont‐driven sulfur crystal formation in a thiotrophic symbiosis from deep‐sea hydrocarbon seeps

The siboglinid tubeworm Sclerolinum contortum symbiosis inhabits sulfidic sediments at deep-sea hydrocarbon seeps in the Gulf of Mexico. A single symbiont phylotype in the symbiont-housing organ is inferred from phylogenetic analyses of the 16S ribosomal ribonucleic acid (16S rRNA) gene and fluorescent in situ hybridization. The phylotype we studied here, and a previous study from an arctic hydrocarbon seep population, reveal identical 16S rRNA symbiont gene sequences. While sulfide is apparently the energy source for the symbionts (and ultimately the gutless host), both partners also have to cope with its toxicity. This study demonstrates abundant large sulfur crystals restricted to the trophosome area. Based on Raman microspectroscopy and energy dispersive X-ray analysis, these crystals have the same S8 sulfur configuration as the recently described small sulfur vesicles formed in the symbionts. The crystals reside adjacent to the symbionts in the trophosome. This suggests that their formation is either extra- or intracellular in symbionts. We propose that formation of these crystals provides both energy-storage compounds for the symbionts and serves the symbiosis by removing excess toxic sulfide from host tissues. This symbiont-mediated sulfide detoxification may have been crucial for the establishment of thiotrophic symbiosis and continues to remain an important function of the symbionts.

Impact of fs and ns pulses on indium and sulfur doped gallium selenide crystals

The impact of fs and ns pulses on indium and sulfur doped gallium selenide crystals with four and five different doping concentrations, respectively, has been studied in comparison with that of undoped GaSe. The inconsistence of the visual criterion of the damage threshold determination has been demonstrated. The multiphoton absorption and thermal effect have been identified as key factors limiting fs and ns pulse pump intensities, respectively. High advantages in the limit pump intensity as up to 50% for optimally indium-doped crystal and up to 4.5 times for optimally sulfur-doped crystal have been demonstrated under fs pulses expose.

Synthesis of one-dimensional metallic sulfur inside the nano-confined spaces of carbon nanotubes

Elemental sulfur, one of the most important natural resources in the chemical industry, has been used mainly for the production of sulfuric acid, vulcanization of rubber, and fertilizers. Despite its importance, sulfur has been regarded as an abundant resource due to the fact that its use is limited to being an inexpensive reagent. Here we report the synthesis of one-dimensional crystals of sulfur using the quasi one-dimensional channels of carbon nanotubes. This one-dimensional phase is confirmed by high resolution transmission electron microscopy and X-ray diffraction, revealing monatomic zigzag and linear sulfur chains inside the constrained volume of the carbon nanotubes. In addition, X-ray diffraction exhibits asymmetric Bragg peaks, indicating the formation of one-dimensional sulfur “crystals”. Most importantly, the one-dimensional sulfur crystals exhibit a metallic character at ambient pressure, whereas bulk sulfur requires ultra-high pressures exceeding ∼ 90 GPa to become metallic. These results lead us to believe that elemental sulfur has great potential to be used as a metal wire in the nanoscale, thus paving a way for future applications. [TANSO 2013 (No. 260) 292–6.]

Synergy of nanoconfinement and surface oxygen in recrystallization of sulfur melt in carbon nanocapsules and the related Li–S cathode properties

We studied the recrystallization behaviours of sulfur melt in oxygen-containing carbon nanocapsules (CNCs). The effects of the oxidizing degree and the nanoconfinement of CNCs on sulfur recrystallization were investigated. We performed weak oxidation on CNCs by firstly grafting >C-Cl3 groups via a Friedel-Craft reaction and successive hydrolysis of >C-Cl3; and the strong oxidation was conducted in nitric acid. It is found that the weak oxidation preserved the CNC structure while the strong oxidation damaged the CNC morphology. Electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray absorption spectroscopy were combined to characterize the sulfur crystallites in pristine and oxidized CNCs. The results revealed that the smaller sulfur crystallites preferentially formed in integrated CNCs (preserved nanoscale hollow structure) regardless of oxygen content; while the stronger oxidation and destruction of hollow structures fostered the growth of larger sulfur crystals. These results suggest a possible approach to control the growth of sulfur in carbon by combining oxygen and nanoconfinement effects, and hopefully to tune the related electrochemical properties in Li–S battery cathodes.

Suppression of H2S gas generation from the 75Li2S·25P2S5 glass electrolyte by additives

Solid electrolytes in the system Li2S–P2S5 are attractive for all-solid-state lithium batteries since the electrolytes have high lithium ion conductivities and wide electrochemical windows. In particular, the 75Li2S·25P2S5 (mol%) glass showed the highest stability to moisture in the system Li2S–P2S5 because the amount of H2S gas generated from the glass was the smallest in the system Li2S–P2S5. In this study, several additives such as metal sulfides and metal oxides (FeS, CuO, etc.) were mixed with the 75Li2S·25P2S5 glass in order to suppress H2S gas generation from the sulfide glasses in air. The addition of more than 30 mol% FeS greatly decreased H2S gas generation from the sulfide glass in air. In the case of the FeS addition, sulfur crystal was precipitated and the 75Li2S·25P2S5 glass changed to Li3PO4 crystal after a reaction with water. On the other hand, the addition of 30 mol% CuO dramatically decreased H2S gas generation from the sulfide glass in air. In the case of the CuO addition, Cu3PS4 crystal was precipitated after the reaction with water. Furthermore, the 75Li2S·25P2S5 glass added with 30 mol% FeS or CuO showed relatively high conductivities of more than 10−4 S cm−1 at room temperature. Therefore, the 75Li2S·25P2S5 glass added with FeS or CuO was expected to be a suitable solid electrolyte material for all-solid-state batteries.

The Kalatongke magmatic Ni–Cu deposits in the Central Asian Orogenic Belt, NW China: product of slab window magmatism?

The Permian Kalatongke Ni–Cu deposits in the Central Asian Orogenic Belt are among the most important Ni–Cu deposits in northern Xinjiang, western China. The deposits are hosted by three small mafic intrusions comprising mainly norite and diorite. Its tectonic context, petrogenesis, and ore genesis have been highly contested. In this paper, we present a new model involving slab window magmatism for the Kalatongke intrusions. The origin of the associated sulfide ores is explained in the context of this new model. Minor amounts of olivine in the intrusions have Fo contents varying between 71 and 81.5 mol%, which are similar to the predicted values for olivine crystallizing from coeval basalts in the region. Analytic modeling based on major element concentrations suggests that the parental magma of the Kalatongke intrusions and the coeval basalts represent fractionated liquids produced by ∼15% of olivine crystallization from a primary magma, itself produced by 7–8% partial melting of depleted mantle peridotite. Positive e Nd values (+4 to +10) and significant negative Nb anomalies for both intrusive and extrusive rocks can be explained by the mixing of magma derived from depleted mantle with 6–18% of a partial melt derived from the lower part of a juvenile arc crust with a composition similar to coeval A-type granites in the region, plus up to 10% contamination with the upper continental crust. Our model suggests that a slab window was created due to slab break-off during a transition from oceanic subduction to arc–arc or arc–continent collision in the region in the Early Permian. Decompression melting in the upwelling oceanic asthenosphere produced the primary magma. When this magma ascended to pond in the lower parts of a juvenile arc crust, it underwent olivine crystallization and at the same time triggered partial melting of the arc crust. Mixing between these two magmas followed by contamination with the upper crust after the magma ascended to higher crustal levels formed the parental magma of the Kalatongke intrusions. The parental magma of the Kalatongke intrusions was saturated with sulfide upon arrival primarily due to olivine fractional crystallization and selective assimilation of crustal sulfur. Sulfide mineralization in the Kalatongke intrusions can be explained by accumulation of immiscible sulfide droplets by flow differentiation, gravitational settling, and downward percolation which operated in different parts of the intrusions. Platinum-group element (PGE) depletion in the bulk sulfide ores of the Kalatongke deposits was due to depletion in the parental magma which in turn was likely due to depletion in the primary magma. PGE depletion in the primary magma can be explained by a relatively low degree of partial melting of the mantle and retention of coexisting sulfide liquid in the mantle.

Preparation, simulation and applications of monodisperse sulphur particles (overview)

The current interest in monodispersed hard spheres is caused by their applicability to the fabrication of photon crystals, three-dimensional nanoporous materials, repellents, etc. The nucleation and growth of sulphur particles in solutions are also of importance because it is known that monodisperse colloid spherulites of solution-stable amorphous sulphur form in acidified aqueous solutions of thiosulfates. Homogeneous nucleation and growth of monodisperse spherulites of sulphur was studied using an original optical method for measuring relative scattering coefficient, based on alternative application of coherent radiation of two lasers with different wavelengths. The model for homogeneous nucleation of sulphur crystals has been developed, which considers the nuclei ranging from n to n × 10² atoms and uses the non-continuous calculations. By the change pH water solutions of thiosulphates and polysulphides of alkaline and alkaline earth metals were obtained submicronic globular particles of sulphur. Various ways of obtaining polymeric composites on the basis of nanosized particles of sulphur are studied. They are submitted based on the decomposition of unstable compounds of sulphur and the nucleation process of sulphur from multicomponent systems of high-supersaturation. Various aspects of application of sulphur nanoparticles in the agriculture, construction, coatings and in high technologies are considered.

Hydro-mechanical behavior of a newly developed sulfur polymer concrete

This study has focused on evaluating the durability of the newly manufactured sulfur polymer concrete (SPC) from recycled waste materials such as sulfur (by-product from oil industry), fly ash (recovered from the gases of burning coal during the production of electricity) and desert sand from abundant sand dunes quarries. The first step in such manufacturing process is the sulfur modification using polymeric additives to control sulfur crystallization and to prevent macro-crystals growth. In a controlled temperature surroundings, modified sulfur was mixed with elemental sulfur, fly ash and desert sand to form the newly SPC. The durability of the SPC was evaluated in: de-ionized water, acidic solutions of 20, 40, 70, and 98 wt% H2SO4 solutions, and saline solutions of 0.5, 1, 2, 3, 4, and 5 wt% NaCl, at different temperatures for different periods of time. To compare the SPC results with known material, normal Portland cement concrete (PCC) mortars were also studied. The results indicated that the manufactured SPC material has high compressive strength, low hydraulic conductivity, and high resistance to permeation of water, and particularly resistant to corrosion in acid and salt environments.

Sulfur crystal through a microscope. © Photo Disc, Inc. (Chem. Eng. Technol. 12/2008)

Chemical Engineering & TechnologyVolume 31, Issue 12 Cover Picture Sulfur crystal through a microscope. © Photo Disc, Inc. (Chem. Eng. Technol. 12/2008) First published: 25 November 2008 https://doi.org/10.1002/ceat.200890053AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume31, Issue12December, 2008 RelatedInformation