Structure Of Salt Research Articles

Basic magnesium carbonate template assisted co-carbonization of potassium citrate toward hierarchical porous carbon for supercapacitors

Hierarchical porous carbon (HPC) as the ideal host material for supercapacitors has received extensive attention. However, traditional methods of fabricating HPC often rely on organic macromolecules and complex procedures. Herein, a simple and straightforward approach is developed for the synthesis of HPC through basic magnesium carbonate template assisted co-carbonization of potassium citrate. Potassium citrate can be effectively embedded and encapsulated with basic magnesium carbonate due to the large bulk density difference between them. In the pyrolysis process, the carbon-containing small molecules produced by the pyrolysis of potassium citrate are deposited on the surface of MgO surface obtained from the decomposition of basic magnesium carbonate, and the etching reaction of potassium salt, CO2 and primary carbon structure occurs. The competitive rate of carbon deposition reaction and etching reaction can be easily controlled by changing the ratio of potassium citrate and basic magnesium carbonate. The obtained carbon materials show the morphology changes of nanoparticle accumulations, discontinuous carbon frames and carbon planar blocks, and the hierarchical porous structure of carbon materials can also be controlled in a wide range. HPC-2 exhibits the morphology of nanoparticle accumulation and generates abundant meso-macropores, which accelerates the rapid transport of electrolytic ions. The micropores inside the nanoparticles provide an accessible room for ionic adsorption. Benefited from this unique microstructural framework, HPC-2 shares a high capacitance of 305.5 F g−1 at 0.5 A g−1 and 173.1 F g−1 at 50 A g−1. Furthermore, the assembled symmetric supercapacitors exhibit a high energy density and power density than YP-50 F throughout the test range. The versatility of this synthetic strategy provides an insight into directional tailoring fine pore structure and micro-morphology of carbon materials based on small molecule deposition.

Structural, optical, and electrical properties of multi-component P-type oxide-semiconductor Cu-Mn-Sn-O thin films

P-type oxide semiconductors have attracted significant attention as conducting channel layers due to their wide applications in electronic devices. In this study, multi-component oxide-semiconductor Cu1–2xMnxSnxO thin films with x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, and 0.33 were prepared on glass substrates using a solution process accompanied by a spin-coating technique. A phase transition between the cupric oxide monoclinic structure and the rock salt structure was observed with increasing concentrations of Mn and Sn, while the concentration of Cu simultaneously decreased in the precursors. The crystallite size decreased throughout the samples, reaching a minimum value of 9.8 nm at an equimolar ratio. Scanning electron microscopy further confirmed this downward trend and indicated an improvement in the quality of the film surfaces. According to the optical absorption measurements, the bandgap energy ranged from 2.68 to 3.44 eV. Interestingly, the sheet resistance of Cu1–2xMnxSnxO films dropped sharply from 5.24 kΩ/sq for CuO to 0.034 kΩ/sq for the film with a molar ratio of Cu:Mn:Sn being 34:33:33.

Stress Field Dynamics and Fault Slip Potential in the Paradox Basin

AbstractThe Paradox Basin, straddling Utah, Colorado, Arizona, and New Mexico is characterized by an intricate amalgamation of evaporites and clastic layers and is dominated by prominent salt walls and related subsurface structures. Our research offers a new examination of the stress distribution across the basin, deriving from continuous and discrete stress measurements conducted in boreholes in the region and focal mechanism analysis, emphasizing variations over salt structures. Integrating Coulomb failure criteria with probabilistic methods, we assess potential fault movements resulting from fluid pressure alterations. Our approach provides a comprehensive understanding of the Paradox Basin's state of stress, showing a continuous change of the maximum horizontal stress orientation from N‐S at the Wasatch Fault Zone to WNW‐ESE in the northern part of the Paradox Basin and to WSW‐ENE in the southern part of the basin. Further East, into the Colorado Plateau and the Uncompahgre Uplift, the SHmax orientation becomes E‐W. Decoding stress orientation dynamics has enabled critical insights into fault slip potential, especially in the basin's northern region. The salt wall faults are less likely to slip, and the Paradox Formation's evaporite and clastic rock sequence can serve as a potential low seismic risk target for carbon storage and hydrocarbon extraction.

Crystal Structure of Lanthanide Salts with 2,4-Dichlorophenoxyacetic Acid

Crystal Structure of Lanthanide Salts with 2,4-Dichlorophenoxyacetic Acid

Amphoteric feature of 3,5-diamino-6-hydroxy-2-oxide-4-nitropyrimidone and its highly-stable energetic anionic salts

Most energetic molecules can only form cations or anions, limiting the structural diversity and performance regulation. In this study, we have presented the interesting amphoteric feature of 3,5-diamino-6-hydroxy-2-oxide-4-nitropyrimidone (DHON), which can be transformed into both DHON− anion and DHON+ cation. The structures of the amphoteric salts were characterized by using single-crystal x-ray diffraction, and their energy (density, heat of formation, detonation velocity, and detonation pressure) and stability (thermal decomposition temperature, impact sensitivity, and friction sensitivity) were also carefully studied. Results indicate DHON− anionic salts exhibit very promising stabilities, much superior to DHON+ cationic salts. Especially, the hydroxylaminium salt exhibits an extremely high thermal decomposition temperature of 309 °C. The x-ray data and quantum calculations show that the DHON− anion has stronger conjugation and H-bonds than the DHON+ cation, thus leading to the higher stability.

Defect-Driven Configurational Entropy in the High-Entropy Oxide Li1.5MO3-δ.

Layered lithiated oxides are promising materials for next generation Li-ion battery cathode materials; however, instability during cycling results in poor performance over time compared to the high capacities theoretically possible with these materials. Here we report the characterizations of a Li1.47Mn0.57Al0.13Fe0.095Co0.105Ni0.095O2.49 high-entropy layered oxide (HELO) with the Li2MO3 structure where M = Mn, Al, Fe, Co, and Ni. Using electron microscopy and X-ray spectroscopy, we identify a homogeneous Li2MO3 structure stabilized by the entropic contribution of oxygen vacancies. This defect-driven entropy would not be attainable in the LiMO2 structure sometimes observed in similar materials as a secondary phase owing to the presence of fewer O sites and a 3+ oxidation state for the metal site; instead, a Li2-γMO3-δ is produced. Beyond Li2MO3, this defect-driven entropy approach to stabilizing novel compositions and phases can be applied to a wide array of future cathode materials including spinel and rock salt structures.

A systematic study of solvation structure of asymmetric lithium salts in water

Aqueous electrolytes are promising in large-scale energy storage applications due to intrinsic low toxicity, non-flammability, high ion conductivity, and low cost. However, pure water’s narrow electrochemical stability window (ESW) limits the energy density of aqueous rechargeable batteries. Water-in-salt electrolytes (WiSE) proposal has expanded the ESW to over 3 V by changing electrolyte solvation structure. The limited solubility and WIS electrolyte crystallization have been persistent concerns for imide-based lithium salts. Asymmetric lithium salts compensate for the above flaws. However, studying the solvation structure of asymmetric salt aqueous electrolytes is rare. Here, we applied small-angle x-ray scattering (SAXS) and Raman spectroscope to reveal the solvation structure of imide-based asymmetric lithium salts. The SAXS spectra show the blue shifts of the lower q peak with decreased intensity as the increasing of concentration, indicating a decrease in the average distance between solvated anions. Significantly, an exponential decrease in the d-spacing as a function of concentration was observed. In addition, we also applied the Raman spectroscopy technique to study the evolutions of solvent-separated ion pairs (SSIPs), contacted ion pairs (CIPs), and aggregate ions (AGGs) in the solvation structure of asymmetric salt solutions.

New proportion of levofloxacin citrate: Structural, physicochemical properties, and potency studies

Stability and potency improvement have been reported by reacting levofloxacin (LF) with citric acid (CA) in a (1:1) molar ratio. However, CA is known to be irritant to the gastrointestinal tract and should be minimized. In a novel approach, this experiment aimed to prepare LF – CA salt with reduced CA, the (2:1) molar ratio, study the structure, and investigate its solubility, stability, and potency improvement. Solvent-dropped grinding and slow evaporation methods were used to prepare the new ratio composition salt, characterized by electrothermal, differential scanning calorimetry, and powder X-ray diffractometry to confirm the physically new solid-state formation. Next, Fourier transform spectrophotometry identified the chemical interaction between LF and CA. After that, a comprehensive structural study using single-crystal X-ray diffractometry determined the 3D structure of the new salt, which determined the solid physicochemical behavior. Finally, stability, solubility, and potency tests were done to investigate the benefits of the new LF-CA composition. As a result, this experiment successfully synthesized the salt, which bound 4.5 water molecules, named LFCA (2:1) - 4.5 hydrate. This new solid-state salt was comparable with the established (1:1) molar ratio in solubility, stability, and potency, higher than LF alone. Hereafter, with a reduced CA portion, this new composition holds potential for further development in drug formulation as a stable, safer, and more efficient antibiotic.

Water-Soluble and Freezable Aluminum Salt Vaccine Adjuvant.

Particulate aluminum salts have long occupied a central place worldwide as inexpensive immunostimulatory adjuvants that enable induction of protective immunity for vaccines. Despite their huge benefits and safety, the particulate structures of aluminum salts require transportation and storage at temperatures between 2 °C and 8 °C, and they all have exquisite sensitivity to damage caused by freezing. Here, we propose to solve the critical freezing vulnerability of particulate aluminum salt adjuvants by introducing soluble aluminum salts as adjuvants. The solubility properties of fresh and frozen aluminum chloride and aluminum triacetate, each buffered optimally with sodium acetate, were demonstrated with visual observations and with UV-vis scattering analyses. Two proteins, A244 gp120 and CRM197, adjuvanted either with soluble aluminum chloride or soluble aluminum triacetate, each buffered by sodium acetate at pH 6.5-7.4, elicited murine immune responses that were equivalent to those obtained with Alhydrogel®, a commercial particulate aluminum hydroxide adjuvant. The discovery of the adjuvanticity of soluble aluminum salts might require the creation of a new adjuvant mechanism for aluminum salts in general. However, soluble aluminum salts might provide a practical substitute for particulate aluminum salts as vaccine adjuvants, thereby avoiding the risk of inactivation of vaccines due to accidental freezing of aluminum salt particles.

Triazolium bromoferrates – An alternative choice for ionic liquids

Four triazolium salts of iron were synthesized. One of them had melting point below 100 °C classifying it as an ionic liquid. Crystal structures of three salts were measured by X-Ray diffraction. DFT calculations of the synthesized anions were performed in order to help with the identification of measured Raman spectra signals, which were used to confirm the presence of tetrabromoferrate anions. Conductivities of the solutions of synthesized salts as well as their solid state conductivities were measured, confirming them as useful electrolytes and solid state conductors. This research expands the scope of cations of ionic liquids to rarely used in this regard triazoles. Additionally, atypical anions namely FeBr4− and FeBr42− were used giving interesting insights into crystal structures of triazolium ferrate salts.

Generation of reverse time migration dip gathers with the stabilized Poynting vector and their application in the improvement of subsalt images

Subsalt imaging is challenging with coherent noise prevalent beneath complex salt structures. The coherent noise degrades the imaging quality, making image enhancement and interpretation difficult and potentially erroneous. The dip gathers of reverse time migration (RTM) serve as an ideal domain for separating signals from coherent noise due to their distinct distributions in the dip domain. Methods utilizing the Poynting vector offer an efficient and cost-effective means to produce dip gathers. However, the presence of zero points in the Poynting vector causes instabilities in direction or angle estimation, leading to the leakage of reflection energy into false dip angles. This issue complicates the separation of desired signals from coherent noise. We address this instability by employing a stabilized Poynting vector to produce high-quality RTM dip gathers. The stabilized Poynting vector does not contain zero points within the range of wave propagation, thus mitigating the instability problem. The dip gathers generated using the stabilized Poynting vector provide a clearer and more precise depiction of signal and noise distributions, allowing us to identify the boundaries of desired signals and mute all noise outside these boundaries. Two numerical examples with a synthetic dataset and a field dataset are used to demonstrate our method's effectiveness in reducing coherent noise and improving quality of subsalt images.

Exploring structural phase transition, electronic and optical characteristics of optoelectronic phosphides XSiP2 (X = Mg, Cd, and Zn) through First principle computation.

The present study reports the properties of pressure-induced phase transition, electronic and optical of phosphides XSiP2 under pressure in chalcopyrite, sodium chloride (rock salt), and Wurtzite phases. The study shows the chalcopyrite phase as the most stable phase among the other studied phases. The obtained structural parameters in the chalcopyrite and rock-salt phases reasonably agree with the literature. The computed band structures revealed a semiconductor behavior in chalcopyrite structure and metallic behavior for rock- salt and wurtzite structures. In the energy range of 0 to 30eV, optical parameters such as the real and imaginary parts of the dielectric constant, refractive index, and reflectivity are calculated and compared with existing data. Our optical properties findings are predictive for the rock-salt and wurtzite phases. Since no results are available in the literature, these results may serve as references for other theoretical and experimental studies. The calculations are performed by employing the "full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT)."

A Cyanine with 83.2% Photothermal Conversion Efficiency and Absorption Wavelengths over 1200 nm for Photothermal Therapy.

Developing small-molecule photothermal agents (PTAs) with good near-infrared-II (NIR-II) response for deeper tissue penetration and minimizing damage to healthy tissues has attracted much attention in photothermal therapy (PTT). However, concentrating ultra-long excitation wavelengths and high photothermal conversion efficiencies (PCEs) into a single organic small molecule is still challenging due to the lack of suitable molecular structures. Here, six polymethine cyanine molecules based on the structure of indocyanine green are synthesized by increasing the conjugated structure of the two-terminal indole salts and the number of rigid methine units, and incorporating longer alkyl side chains into the indole salts. Ultimately, IC-1224 is obtained with an absorption wavelength of more than 1200nm, which has a high PCE up to 83.2% in the NIR-II window and exhibits excellent PTT tumor ablation performance. This provides a high-performance NIR-II-responsive PTA, and offers further possibilities for the application of PTT in biomedical fields.

First-Principles Investigation of the Effects of UF4 and ThF4 Fuels on the Structural, Dynamic, and Thermodynamic Properties of LiF-NaF.

An in-depth understanding and characterization of molten salt properties are necessary for the optimized design, efficient operation, and safety assurance of molten salt reactors (MSRs). Investigating molten salt properties in experimental settings can be challenging and time-consuming due to the high temperatures of interest, the salt's corrosiveness, purity and composition control, and health and safety concerns. Therefore, it is beneficial to perform computational screening to assist in the ultimate experimental measurements. Herein, we used first-principles molecular dynamics simulations to calculate several thermophysical, structural, and dynamic properties of eutectic LiF-NaF with fuel additives UF4 and ThF4. We found that with the incorporation of uranium or thorium, a prepeak appears in the structure factor, indicative of a medium-range structural ordering. Furthermore, we explore the mechanism through which these structural changes enhance shear stress correlations, thereby increasing the salt's viscosity. This work highlights the importance of studying the atomic-scale structure of molten salts and how the addition of fuel elements can substantially affect it.

Three millennia of salt production: Briquetage and salt structures on the east coast of Lincolnshire, England

While salt-making sites of Prehistoric, Roman and Medieval date have been known about for the best part of 200 years along the Lincolnshire Coast and Fenland, investigations have been patchy. The recognition that briquetage was connected to salt-making came early and a number of sites were revealed when sand was removed from beaches during storm events in the early 20th century. This led to spates of investigations culminating in the Fenland Project in the 1980s–90s. Since then, the deployment of LiDAR techniques to flood management by Government agencies has resulted in micro-topographical maps of the ancient wetland landscape adding to the general picture of the former wetland and enabling a fuller understanding of its extent and uses. Investigations in two landscape zones, each with seemingly different intensities of salt-making, has enabled comparisons to be made between the areas and an additional dimension of the industry to be investigated. However, there remains much to accomplish, including understanding the full extent of the industry now partially lost through post-saltern flood depositions and coastal erosion.

Molecular dynamics simulation studies elucidating interaction mechanisms and structures of salt–brine interfacial systems derived from magnesium sulfate subtype salt lakes

Salt–brine interfacial systems widely occur in the process of salt crystallization and separation, where the interfacial interaction plays a crucial role in influencing salt crystal growth, product purity and brine recovery rates. In the present study, molecular dynamics simulations were employed to investigate the interaction mechanisms and structures of salt–brine interfacial systems derived from the magnesium sulfate–subtype salt lakes. The results indicate that the type of salts was the key factor that affects salt–brine interfacial interactions. The strength of interfacial interaction in hydrated salt–brine systems was found to be more than twice that of ionic salt–brine systems. This can be attributed to two characteristics observed in hydrated salt–brine systems: the incompact and undulating surface structure of hydrated salts and the hydrogen bonding between water molecules on hydrated salt and brine surfaces. In all the seven interfacial systems, no accumulation of Li+ ions at the interface was observed, and there were no significant structure changes in bulk brines except the variations in hydration numbers of K+ ions. These findings provide insights into atomic-level mechanisms governing the interfacial interactions between different types of salts and brines, thus providing a theoretical guidance for enhancing the salt crystallization and separation process.

Hirshfeld surface analysis, experimental and theoretical evaluation of a new monohydrated organic salt of 2-amino-4‑hydroxy-6-methylpyrimidine (AHMP) and 4-acetamidobenzoic acid (AMBA) for nonlinear optical applications

The organic crystal (AHMP+.AMBA−) of the AHMP and AMBA organic compounds was successfully synthesized and grown by the slow evaporation solution process. The present work focuses on the crystal structure, Hirshfeld surface, spectroscopic and DFT analyses of the title salt. The crystal geometry of AHMP+.AMBA− monohydrated salt was characterized by the single-crystal XRD technique. The synthesized salt crystallizes in the triclinic crystal system and P-1 space group. The identification of the functional groups of the compound has been done by FTIR spectroscopy and DFT/B3LYP-D3/6–311++G(d,p) level of theory. Further, Hirshfeld surface mapping and its associated two-dimensional fingerprint plots predict that the O⋅⋅⋅H and H⋅⋅⋅H interactions are dominant for stabilizing the crystal structure. TG-DTA reveals the crystal is thermally stable up to 168 ºC. The optical studies have been performed by the time-dependent DFT (TD-DFT) and UV–Vis spectroscopic methods. Moreover, the Z-scan experiment has been done to obtain third-order NLO properties. Additionally, the HOMO-LUMO energy gap, MEP maps and theoretical NLO parameters have also been calculated.

From zwitterion 5-diazonium-3-trinitromethyl-1,2,4-triazolate to high-energy salts with relatively low sensitivity

High energy in energetic materials often leads to high sensitivity, which can diminish their utility. The zwitterion 5-diazonium-3-trinitromethyl-1,2,4-triazolate possesses extremely high energy (Dv = 9317 m s–1), but the sensitivity is exceptionally high (IS < 1 J). Here, we cleverly convert the diazo groups into azido groups, thus disrupting its internal salt structure. Subsequently, by adding appropriate bases, four energetic salts with 3-azido-5-dinitromethyl-1,2,4-triazole as the anion are prepared. While maintaining high energy, the sensitivity of all energetic salts is reduced (Dv ≥ 8444 m s–1, IS ≥ 3 J). Among them, compound 3 exhibits the best overall performance (Dv = 9176 m s–1, Td = 170 °C, IS = 10 J) and has the potential to be a secondary explosive.

A Chlorinated Indolium‐Based Nonlinear Optical Crystal Achieving Effective Terahertz‐Wave Generation and Highly Sensitive Detection

AbstractNonlinear optical (NLO) crystals have shown great potential in generating and detecting coherent terahertz waves, which have a wide range of applications. However, designing the microscopic structure of NLO crystals to obtain excellent macroscopic properties has been a challenge. In this work, by the introduction of chloro substitution into the cation part of indolium‐based salt structure, a new acentric OH5CI‐BS crystal, namely, [(C19H19NOCl)+∙(C6H5SO3)−, P1] is synthesized and grown using a feasible evaporation method. The cut‐off edge of the grown OH5CI‐BS crystal reaches 524 nm, corresponding to a bandgap of 2.37 eV. The largest single crystals of OH5CI‐BS with the size of ≈ 9 × 8 × 0.3 mm3 are grown. Remarkably, by use of OH5CI‐BS crystals as both the THz‐wave emitter and detector, a widely tunable (from 2.23 to 33.54 THz) and monochromatic THz system is demonstrated for the first time, and the detection depth of the OH5CI‐BS based up‐conversion at room temperature is &gt;4 orders better than a commercial Golay Cell and even 2 orders better than a 4‐K‐Bolometer. This work indicates that OH5CI‐BS is a promising future NLO material for terahertz technology, and also provides a feasible design strategy for other organic optoelectronic functional materials.

Theoretical study on the structure and properties of energetic salts with catenated N11 cation

Theoretical study on the structure and properties of energetic salts with catenated N11 cation