Sulfate Crystals Research Articles

A Non-π-Conjugated Molecular Crystal with Balanced Second-Harmonic Generation, Bandgap, and Birefringence.

Traditional nonlinear optical (NLO) crystals are exclusively limited to ionic crystals with π-conjugated groups and it is a great challenge to achieve a subtle balance between second-harmonic generation, bandgap, and birefringence for them, especially in the deep-UV spectrum region (Eg >6.20eV). Herein, a non-π-conjugated molecular crystal, NH3 BH3 , which realizes such balance with a large second-harmonic generation response (2.0× KH2 PO4 at 1064nm, and 0.45 × β-BaB2 O4 at 532nm), deep-UV transparency (Eg > 6.53eV), and moderate birefringence (Δn = 0.056@550nm) is reported. As a result, NH3 BH3 exhibits a large quality factor of 0.32, which is evidently larger than those of non-π-conjugated sulfate and phosphate ionic crystals. Using an unpolished NH3 BH3 crystal, effective second-harmonic generation outputs are observed at different wavelengths. These attributes indicate that NH3 BH3 is a promising candidate for deep-UV NLO applications. This work opens up a new door for developing high-performance deep-UV NLO crystals.

Magnetically Induced Effects in Ferroelectric Triglycine Sulfate Crystals with Chromium Impurity

The influence of a permanent magnetic field on macro- and nanoscopic properties of triglycine sulfate (TGS) crystals with impurity chromium (TGS-Cr) has been investigated. This work continues the previous studies of magnetically induced effects in ferroelectrics. A specific feature of TGS crystals is the presence of a nanoscale relief on a polar (010) cleavage; this nanorelief is a qualitative characteristic of the crystal defect structure. It is shown that the exposure of a crystal in a magnetic field of 2 T leads to a change in its dielectric properties, accompanied by a long-term transformation of the nanorelief. The results obtained are indicative of a magnetically induced change in the defect crystal structure. A qualitative difference is found between the magnetically induced effects in TGS-Cr crystals and undoped TGS crystals. The relationship between the magnetically induced effects and structural defects is discussed.

The effect of a static magnetic field on the low-frequency dielectric permittivity of nominally pure and Co<sup>2+</sup> ions doped triglycine sulfate crystals

The effect of a weak static magnetic field on the low-frequency dielectric permittivity of the crystals of nominally pure triglycine sulfate (TGS): and TGS containing cobalt ions (TGS + Co2+) is investigated. In TGS, the magnetic effect is essentially anisotropic: it is completely absent when the vectors \(\vec {B}\) and \({{\vec {P}}_{{\text{s}}}}\) are collinear and is most pronounced when \(\vec {B} \bot {{\vec {P}}_{{\text{s}}}}\) and the magnetic field is oriented along the crystallophysical axis \(\vec {a}\). In TGS + Co2+ magnetic effect is noticeably stronger than in TGS, but practically does not depend on the mutual orientation of vectors \(\vec {B}\) and \({{\vec {P}}_{{\text{s}}}}\).

Effect of a Static Magnetic Field on the Low-Frequency Dielectric Permittivity of Triglycine Sulfate Crystals Nominally Pure or Doped with Со2+ Ions

Effect of a Static Magnetic Field on the Low-Frequency Dielectric Permittivity of Triglycine Sulfate Crystals Nominally Pure or Doped with Со2+ Ions

Mechanoluminescence of samarium(III) sulfate crystals activated by ultrasound

The mechanoluminescence (ML) was detected, when Sm2(SO4)3·8H2O crystals were exposed to a titanium waveguide with a 22 kHz ultrasonic disperser. It was shown that ML of this salt is not recorded during grinding with a stirrer compared to that found previously for any other Ln3+ crystal hydrates (Ln = Ce, Pr, Gd, Eu, Tb, and Dy). This is mainly because of low quantum yield of Sm3+ photoluminescence (PL) compared to those of these ions. The ultrasound increases significantly the rate and intensity of a mechanical action on the crystals to provide a stable and bright glow sufficient to record an ML spectrum. The lines of molecular nitrogen are observed at 290–430 nm in the luminescence spectrum in air atmosphere. The luminescence of Sm3+ ion is also detected with maxima at 560, 595, 640, 700, and 781 nm that correspond to the 4G5/2 → 6Hj/2 transitions and coincide with quasilines in a PL spectrum of the samarium(III) sulfate crystals. The lines of N2 arise due to discharges in the gas phase between surfaces charged oppositely during the ultrasonic treatment of crystals. The ML of Sm3+ ion is probably due to the excitation of luminescence by electroluminescence of crystal phosphors, namely, due to the separation and recombination of charge carriers in the electric field of a crystalline layer arising during mechanical action.

Understanding unsaturated sulfate saline soil in cold regions: A comprehensive hydraulic–thermal–air–salt–mechanical model with experimental research

The destruction of infrastructure built on saline soil in cold regions is closely related to water and salt migration, and soil deformation in foundations. Consequently, it is imperative to understand the mechanisms of heat and mass transfer, along with deformation in saline soil. Based on the unsaturated soil mechanics and porous media theory, a hydraulic–thermal–air–salt–mechanical (HTASM) coupled mathematical model for frozen unsaturated sulfate saline soil is proposed. The model incorporates the impact of ice-water phase change, sodium sulfate crystallization, and vapor flow on heat and mass transfer during the freezing process. Two parameters—salt crystallization pressure, and ice pressure—are introduced into the mechanical control equation to capture the effects of phase change on deformation. In addition, the relationship between the density of soil particles, water, ice and gas, and temperature and pressure is considered to reflect the dynamic change of density during freezing. Finally, the numerical simulation using the HTASM model is conducted and its efficacy is validated by comparing the numerical results with those obtained from indoor unidirectional freezing tests. The coupling effect of the HTASM model is revealed by analyzing the dynamic changes of temperature, water content, salt content, vapor flux and crystallization pressure in the soil column during freezing. The results show that the proposed HTASM model can well simulate the heat and mass transfer behavior in freezing unsaturated sulfate saline soil.

Water column barium sulfate dissolution and shielding by organic matter aggregates: Implications for the pelagic barite proxy

Pelagic barite (BaSO4) and related proxies are useful tools for reconstructing the marine carbon cycle. The factors controlling pelagic barite dissolution in the ocean water column are poorly understood, which adds uncertainty to Ba-based reconstructions. Here, we conducted static laboratory incubations to test the sensitivity of barium sulfate dissolution rate to a range of commonly occurring seawater pH, salinity, and temperature conditions. We observed relatively rapid dissolution rates ranging from 1.7 ± 0.4 to 3.4 ± 0.8 pg BaSO4 day−1 for these experiments, and we did not observe statistically significant differences in the rate of dissolution with varying pH, salinity, or temperature. The slowest dissolution rate observed in these experiments suggests that an average barium sulfate crystal would survive in the ocean water column just 6.2 ± 0.3 days. We estimate that an average isolated pelagic barite crystal would take 67 years to sink down through the water column, so our experiments imply that solitary pelagic barite crystals do not survive this transit. We conducted an additional experiment on a roller table to assess the impact of organic matter aggregates on barium sulfate dissolution. Free barium sulfate crystals incubated on the roller table dissolved even more rapidly than crystals in the static experiment (19 ± 7 pg BaSO4 day−1), but barium sulfate crystals incubated with organic matter aggregates showed little sign of dissolution over time. Our findings suggest that organic matter aggregates play a vital role in shielding pelagic barite from dissolution in the water column. This implies that pelagic barite in ocean sediments records the arrival of organic detritus to the seafloor, not just barite crystal formation in sinking organic matter in the upper water column. Additional work is needed to determine which aspects of the marine carbon cycle the pelagic barite proxy captures.

Solubility, Crystallization, and Characterization of Cytidine Sulfate.

Cytidine is an important kind of nucleoside that can be applied to drug development and food industry. Cytidine sulfate is one of its popular forms, which is promising as a medicinal intermediate, especially in antiviral and antitumor drugs. Product refining is the key point of industrial development, and crystallization is a significant way of refining. In this work, the solubility of cytidine sulfate in pure water from 278.15 to 328.15 K and in water-ethanol binary solvents at 298.15 K was measured by the UV spectroscopic method. The solubility data were correlated with temperature and solvent composition using the modified Apelblat, van't Hoff, and CNIBS/R-K equations. On this basis, we investigated and compared three crystallization processes, and the coupling method was developed to prepare crystals with a large particle size, concentrated distribution, and high yield and packing density. In addition, the structure and stability of the products were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and dynamic vapor sorption analysis. It was found that cytidine sulfate has only one crystal form in our research process, and the product of coupling crystallization is stable and favorable for industrial development.

Deep insight into green remediation and hazard-free disposal of electrolytic manganese residue-based cementitious material

This work presents an innovative approach to developing a low-carbon and hazard-free cementitious material (EGC) by activating ground granulated blast-furnace slag (GGBS) with electrolytic manganese residue (EMR), which has an excellent heavy metal solidified capacity. Herein, the multi-step leaching was creatively conducted to investigate the solidified morphology of heavy metals in hazardous EMR. CO2 emission per unit strength factor was calculated to quantitatively analyze the low-carbon degree. The results show that the added hazardous EMR rich in sulfate and the dilution effect caused by the decrease in GGBS lessen the final setting time and fluidity. Low-temperature calcination (200 °C) alters the dissolution rate of ettringite and AFm-like phases by changing the sulfate crystal. Excessive acidic EMR consumes more calcium hydroxide and lowers the pH of the EGC system, resulting in weakened GGBS activity. The formation of jouravskite, thaumasite, and henritermierite are AFm-like hydrated lamellated structures, which provides evidence for the immobilization of Mn2+ in EMR. Vast Mn2+ are embedded in the main interlayer of [Ca2Al(OH)6]+ by substituting Al to form AFm-like phase. The lowest 60d unit compressive strength carbon emission of the EGC system containing 20 % calcinated EMR is 0.78 kg∙MPa−1∙m−3, meaning the substitution barrier is better addressed by adding calcined EMR. This work provides an innovative solution for high value-added and hazard-free utilization for EMR and carbon reduction in the cement industry.

Leaching of Waste Pharmaceutical Blister Package Aluminium in Sulphuric Acid Media

In this study, the leaching behaviour of aluminium from waste pharmaceutical blister packages (WPBs) is investigated in sulphuric acid media to build future strategies for aluminium recycling from this non-recycled waste fraction. The results suggest that in hydrometallurgical recycling, passivation of aluminium during leaching can be mitigated in dilute sulphuric acid solutions (0.25 M), at high temperatures (60–80 °C) and specifically with H2O2 addition. With this system, 100% extraction was achieved within five hours under optimized conditions (H2SO4 = 0.25 M, T = 80 °C, H2O2 = 1.25 vol.%). The leaching mechanism is suggested to be based on electrochemical dissolution of metallic aluminium oxidized by H+ or H2O2, followed by fast passivation by Al2O3 and consequent chemical dissolution of Al2O3 at slower kinetics. The calculated activation energy (~69 kJ/mol) suggests that the leaching reaction is controlled by the chemical or electrochemical reaction step rather than diffusion. By WPB leaching, an aluminium sulphate solution could be obtained, suitable for further aluminium sulphate crystallization. This may provide a potential route for the valorisation of aluminium from a currently overlooked waste fraction of pharmaceutical blister packages.

Modeling and Predictive Control of Cooling Crystallization of Potassium Sulfate by Dynamic Image Analysis: Exploring Phenomenological and Machine Learning Approaches

Modeling and Predictive Control of Cooling Crystallization of Potassium Sulfate by Dynamic Image Analysis: Exploring Phenomenological and Machine Learning Approaches

Multiscale modeling of ammonia adsorption on zinc sulfate-doped activated carbon: Sensitivity analysis, parameter identification, and model validation

In this study four models are developed and validated to describe the dynamic adsorption of ammonia on zinc sulfate-doped activated carbon, ranging from simple single-scale to complex multiscale models. They are based on equations for mass balance, thermodynamics, hydrodynamics, and adsorption kinetics. Since the values of the parameters are needed for the implementation of the models, the doped activated carbon is characterized and ammonia isotherms measurements are performed at three different temperatures, i.e., 288, 303, and 313 K. A method based on parameter sensitivity analysis is used to evaluate the estimability of the unknown parameters of the Toth isotherm equation. Experimental breakthrough curves were then measured at various ammonia concentrations and gas flow rates. These curves were used to determine the overall mass transfer and axial dispersion coefficients, as well as the effective and intracrystalline diffusion, involved in the model equations. The models were implemented and solved using Comsol Multiphysics®. The study showed that the adsorption process was limited by the diffusion of ammonia and adsorption on the zinc sulfate crystal. The models were validated using breakthrough curves different from those used for parameter identification. The agreement between model predictions and measurements was evaluated using performance indices and confirmed by a Kolmogorov-Smirnov statistical test.

Inhibition of Barium Sulfat Crystal Formation in a Batch Method Crystallizer in the Presence of Cu and Zn

Deposits of barium sulfate are a common issue in the oil and gas industry. The presence of these crystals impacts oil and gas production, causing technical problems such as inhibiting flow rate, increasing pressure in the pipe, and causing the pipe to break and be damaged. The results of this study show the formation of barium sulfate (BaSO4) crystals with the batch crystallizer method at 300 °C under the influence of the stirring rotation speed (0 rpm, 120 rpm, 240 rpm, 360 rpm, 480 rpm) and the additive concentration (0 ppm, 5 ppm, 10 ppm, 15 ppm, 2atm). In this study, the BaSO4 crystallization experiment was performed in a glass beaker using a magnetic stirrer with a stirring rotation speed to react BaCL2 and Na2SO4. The results demonstrated that adding zinc chloride (ZnCl2) and copper (ii) chloride (CuCl2) additives reduced the mass of crystals formed. The amount of barium sulfate scale that forms can be affected by the rotational speed of the stirrer. According to SEM analysis, the crystal morphology of BaSO4 was orthorhombic, indicating that this crystal shape was typical of barite crystals. While XRD analysis confirmed the formation of barium sulfate (barite) crystals, it also demonstrated that the crystals formed were solid barite crystals.

Ferroelectric properties of triglycine sulfate crystals doped with glycine analogs

Single crystals of ferroelectric triglycine sulfate doped with glycine analogs serine, threonine, lactic acid, and alaninol were grown via the slow solvent evaporation method. The resulting ferroelectric domain structures and polarization–electric field hysteresis loops revealed that these dopants caused triglycine sulfate to form a multidomain structure. This was attributed to hydrogen bonds not being formed, which is significant in polarization reversal, due to the side chains and the substituents of the dopant molecules. Therefore, the dopants did not affect the surrounding dipoles enough to cause cooperative phenomena, such as dipole‒dipole interactions, and do not result in the formation of a single- domain, unlike alanine in our previous study.

Parametric study of calcium sulfate crystallization fouling in cross-flow heat exchanger using response surface methodology

Parametric study of calcium sulfate crystallization fouling in cross-flow heat exchanger using response surface methodology

Hybridization of Salt Hydrates with Solid–Solid Phase Change Materials: A Novel Pathway to Sorption Thermochemical Materials Manufacturing

AbstractMajor advancements are needed in the thermochemical energy storage (TCES) field to bring the technology to commercial levels. The current research strategies are focused on improving heat and mass transfer using different supporting materials to achieve mechanical integrity during storage. However, these strategies are still under development, and they have not overcome the lab scale yet. This work explores novel matrices to expand the material database for TCES composites. Pure structural matrices (cellulose) and novel matrices with storage potential (polymeric solid–solid phase change materials) are selected and combined with three well‐known thermochemical materials (TCMs) (MgSO4·6H2O, SrBr2·6H2O and MgCl2·6H2O), providing evidence of hybridized composites with storage capacity up to 2.4 GJ m−3with a 25–20 wt% of polymeric matrix. The polymer content is found to act as a nucleating agent in the magnesium sulfate crystallization process forming a synthetic monohydrate crystalline phase (Kieserite) and inhibiting the formation of the amorphous phase. The effect of the matrix is proved to induce certain structural deformation or changes not observed in the pure TCM sorption process. This phenomenon has the potential to benefit the stabilization of the TCM, e.g., inhibition of the formation of amorphous phase in magnesium sulfate composites.

A Polymorph of Dipeptide Halide Glycyl-L-Alanine Hydroiodide Monohydrate: Crystal Structure, Optical Second Harmonic Generation, Piezoelectricity and Pyroelectricity.

A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters a = 7.747 Å, b = 6.435 Å, c = 10.941 Å, α = 90°, β = 107.53(3)°, γ = 90° and V = 520.1(7) Å3. Crystallization in the polar point group 2, with one polar axis parallel to the b axis, allows pyroelectricity and optical second harmonic generation. Thermal melting of the glycyl-L-alanine HI.H2O polymorph starts at 533 K, close to the melting temperature reported for cyclo-glycyl-L-alanine (531 K) and 32 K lower than that reported for linear glycyl-L-alanine dipeptide (563 K), suggesting that although the dipeptide, when crystallized in the polymorphic form, is not anymore in its cyclic form, it keeps a memory of its initial closed chain and therefore shows a thermal memory effect. Here, we report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than that of semi-organic ferroelectric triglycine sulphate (TGS) crystal. Moreover, the glycyl-L-alanine HI.H2O polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic barium borate (BBO) single crystal. The new polymorph displays an effective piezoelectric coefficient equal to deff=280 pCN-1, when embedded into electrospun polymer fibers, indicating its suitability as an active system for energy harvesting.

Reverse Osmosis Membrane Scaling Inhibition using Kinetic Degradation Fluxion Media

Membrane fouling can lead to reduced efficiency, increased operating costs, and shorter membrane life, which can ultimate[1]ly impact the quality of potable water produced from seawater. The use of Kinetic Degradation Fluxion (KDF) media as a pretreatment method is promising because it can potentially reduce fouling caused by CaCO3 scaling and improve the per[1]formance of RO membranes. The study's methodology, which involves comparing two identical reverse osmosis systems with and without KDF pretreatment, is appropriate and well-designed. By comparing the salt rejection and permeability flow of the two membrane systems, the study can provide valuable insights into the effectiveness of KDF media in reducing foul[1]ing caused by CaCO3 scaling. The explanation of how KDF media works to prevent the formation of mineral hardness scale by altering the morphology of the insoluble Ca and Mg carbonate and sulfate crystals and creating a redox environment is helpful in understanding the potential mechanism behind the effectiveness of KDF media as a pretreatment method. By con[1]trolling the formation of mineral scale and other contaminants, KDF media can potentially lead to improved efficiency of the RO membrane. Results suggest that KDF media can be an effective pretreatment method for reducing fouling caused by mineral scaling in RO systems. The potential mechanism behind the effectiveness of KDF media is explained, and the obser[1]vation that only a small number of KDF discs were degraded over the 40-hour period indicates that KDF media can be used for multiple cycles of RO operation, reducing the frequency of media replacement and associated operating costs. The finding that the RO-KDF membrane remained healthy and efficient for 40 hours while fouling was observed in the RO system with[1]in 20 hours is also promising, as it indicates that the KDF media can effectively reduce membrane fouling caused by scaling, leading to improved efficiency and extended membrane life. However, further studies can explore the optimal conditions for using KDF media in RO systems to maximize its effectiveness in reducing fouling and extending the lifetime of RO mem[1]branes. Investigating the potential for KDF media to reduce fouling caused by other contaminants, such as organic matter or silica, would also be interesting

Monosodium glutamate as an effective electrolyte additive in lead acid battery

High-rate partial state of charge (HRPSoC) life and stability of lead-acid batteries are largely limited by the surface morphology of lead sulfate and the reactivity of anode plates. In this study, sodium glutamate (MSG) was introduced as an electrolyte additive for lead-acid battery to improve lead sulfate deposition process and lead sulfate crystal morphology at the interface between lead anode and sulfuric acid electrolyte, and the influence of MSG on battery performance were explored. By electrochemical tests and material characterization, it was proved that glutamic acid anion can promote the formation of uniform deposition of lead sulfate with a structure similar to stacked flakes, which make it easy to form active lead and restrain irreversible sulfate during the fast charging and discharging process.

ТЕХНОЛОГИЯ КРИСТАЛЛИЗАЦИОННОГО РАЗДЕЛЕНИЯ НИКЕЛЯ И КАДМИЯ ПРИ ПЕРЕРАБОТКЕ НИКЕЛЬ-КАДМИЕВОЙ ЭЛЕКТРОДНОЙ МАССЫ ЩЕЛОЧНЫХ АККУМУЛЯТОРОВ

The main stages of processing nickel-cadmium electrode mass of alkaline batteries, including: sulfuric acid leaching and subsequent crystallization of the main components of the system - cadmium and nickel in the form of double sulfates MSO4·(NH4)2SO4·6H2O (Tutton's salts), where M = Ni, Cd. As a result of the research, regularities in the behavior of nickel and cadmium at the stage of leaching with a solution of sulfuric acid and crystallization of double sulfates were revealed. It is shown that the separation of cadmium and nickel in the sulfuric acid solution of leaching of nickel-cadmium battery mass by crystallization of nickel and cadmium-ammonium double sulfates is achieved in three stages with the formation of crystals of the composition NiSO4·(NH4)2SO4·6H2O, in two stages of crystallization and the degree of extraction of nickel 99 %, as well as CdSO4·(NH4)2SO4·6H2O and CdSO4·(NH4)2SO4 at the third stage of crystallization. Iron remains in solution after all valuable components have been isolated.