Search Results (377)

The separation of particles smaller than 1 µm either by composition or by size is still a challenge. For the separation of SiO₂ and SnO₂, the creation of a selective separation feature and the specific adsorption of salts and surfactants were investigated. The adsorption of various salts, e.g., AlCl₃, ZnCl₂, MnCl₂ and MgCl₂ were therefore analyzed, and the necessary concentration for the charge reversal of the material was determined. It was noticed that the investigated materials differ in their isoelectric point (IEP) and therefore in their adsorption behavior because only ZnCl₂ and MgCl₂ are suitable for a charge reversal of both metal oxides. The phase transfer of the pure material at different pH values with ZnCl₂ or MgCl₂ and sodium dodecyl sulfate (SDS) revealed that the adsorption behavior of the particle has an influence on the phase transfer. As a result, the phase transfer of SiO₂ is pH dependent, whereas the phase transfer of SnO₂ operates over a wider pH range. This allowed the separation of SiO₂ and SnO₂ to be controlled by the salt and surfactant concentration as well as pH. The separation of SiO₂ and SnO₂ was investigated for various parameters such as salt and surfactant concentration, particle concentration and composition of the mixture. Also, pH 8, where a selective phase transfer for SiO₂ occurs, and pH 6, where the greatest difference between the materials exists, were also investigated. By comparing the parameters, it was found that the combination of ZnCl₂/SDS and MgCl₂/SDS enables a selective separation of the materials. Furthermore, it was also found that the concentration of SDS has a significant effect on the separation, as the formation of a bilayer structure is important for the separation, and therefore, higher SDS concentrations are required at higher particle concentrations to increase the separation efficiency. Full article

Wastewater contains dyes originating from textile industries, and above a certain concentration, they can become dangerous due to their high toxicity. Divalent and trivalent metal coagulants, usually aluminum- or iron-based, have been studied worldwide. However, tetravalent coagulants, such as tin chloride, have not yet been extensively studied for application in wastewater treatment. Therefore, in this study, three types of coagulants were examined: SnCl₄, Cs, and a hybrid composite (CS@Sn) in two different mass ratios, abbreviated hereafter as CS@Sn_5% and CS@Sn_50%. The formation of the suggested CS@Sn hybrid coagulants was confirmed by applying SEM, XRD, and FTIR techniques. The results showed that the optimum conditions for RB5 removal was the addition of 20 mg Sn/L SnCl₄ (97.8%) and 50 mg Sn/L of CS@Sn_50% (64.8%) at pH 3.0. In addition, SnCl₄ was found to be an effective coagulant for all the examined anionic dyes, but it was not as effective for cationic dyes. Moreover, the coagulants were then tested in two mixed-dye solutions, both anionic dyes (RB5/RR120) and anionic/cationic (RB5/MV), resulting in a synergistic effect in the first one and a competitive effect in the secon. Finally, the proposed coagulants were successfully tested on real wastewater samples from an untreated textile dyeing industry. Therefore, the coagulants presented in this work for the removal of several dyes are also capable of being used for wastewater treatment. Full article

As part of a systematic study on the structures of the mixed halide isothiocyanates, Sn^IIHal(NCS), their single crystals were grown and structurally characterized. For Hal = F (1), the SnClF structure type was confirmed, while with Hal = Cl (2), Br (3), and I (4), there are three isostructural compounds of a new structure type, and for Hal = Cl (5), there is a second modification of a third structure type. These structure types have been described with respect to the composition and coordination geometry of the first, second, and van der Waals crust coordination spheres and their dependence on the halogen size and thiocyanate binding modes. With respect to the first coordination spheres, all three structure types constitute one-dimensional coordination polymers. In 1, “ladder”-type double chains result from μ₃-bridging fluorine atoms, and in 2–4, single-chains built up from μ₂-halogen atoms are pairwise “zipper”-like interconnected via κ²NS-bridging NCS ligands, which manage the halogen-linked chain assembly in the double chains of 5. Based on the octet rule, short atom distances are interpreted in terms of 2c-2e and various (symmetrical, quasi-symmetrical, and asymmetrical) kinds of 3c-4e bonds. Weak contacts, the topology of which suggests the extension of the latter bonding concept, are identified as electron-deficient, bifurcated tetrel bonds. Full article

The WRKY transcription factor family is a significant family of plant transcription factors (TFs). Plant growth and development are often influenced by abiotic factors, such as salinity and low temperature. Numerous studies have demonstrated that WRKY TFs primarily influence plant responses to adversity. However, there are few studies on the role of WRKY genes in the stress responses of Malus baccata (L.) Borkh. We cloned the MbWRKY33 gene from Malus baccata for this research, and its roles in salt stress tolerance were analyzed. Phylogenetic tree analysis revealed that MbWRKY33 and PbWRKY33 have the highest homology. Subcellular localization revealed that MbWRKY33 was located within the nucleus. An analysis of tissue-specific expression showed that MbWRKY33 had relatively high expression levels in young leaves and roots. Moreover, Arabidopsis thaliana plants overexpressing MbWRKY33 exhibited stronger resistance to salt stress compared with the wild type (WT) and the unloaded line empty vector (UL). Under the treatment of 200 mM NaCl, transgenic Arabidopsis thaliana plants exhibited significantly higher activities of antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) than the control. In contrast, the WT and the UL lines had elevated levels of malondialdehyde (MDA) and reactive oxygen species (ROS). In addition, MbWRKY33 elevates transgenic plant resistance to salt stress by regulating the expression levels of AtNHX1, AtSOS1, AtSOS3, AtNCED3, AtSnRK2, and AtRD29a. Results indicated that MbWRKY33 in Malus might be linked to high-salinity stress responses, laying a foundation for understanding WRKY TFs’ reaction to such stress. Full article

The corrosion behaviors of newly developed solder alloys with excellent mechanical properties, Sn-2.5 Ag-1.0 Bi-0.8 Cu-0.05 Ni (SABC25108N) and Sn-1.5 Bi-0.75 Cu-0.065 Ni (SBC15075N), are analyzed to supplement the corrosion behavior of the limited corrosion data in Pb- and Zn-free solder compositions. A potentiodynamic polarization test is conducted on these compositions in a NaCl electrolyte solution, the results of which are compared with those of conventional Sn-3.0 (wt%) Ag-0.5Cu and Sn-1.2Ag-0.5Cu-0.05Ni alloys. The results indicate that SBC15075N exhibits the lowest corrosion potential and highest corrosion current density, thus signifying the lowest corrosion resistance. By contrast, SABC25108N exhibits the lowest corrosion current density and highest corrosion resistance. Notably, SABC25108N shows a slower corrosion progression in the active state and exhibits the longest passive state. The difference in corrosion resistance is affected more significantly by the formation and distribution of the Ag₃Sn intermetallic compound phase owing to the high Ag content instead of by the presence of Bi or Ni. This uniform dispersion of Ag₃Sn IMC phases in the SABC25108N alloy effectively suppressed corrosion propagation along the grain boundaries and reduced the formation of corrosion products, such as Sn₃O(OH)₂Cl₂, thereby enhancing the overall corrosion resistance. These findings provide valuable insights into the optimal design of solder alloys and highlight the importance of incorporating sufficient Ag content into multicomponent compositions to improve corrosion resistance. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by synaptic dysfunction and neuronal loss due to the accumulation of amyloid-β peptides and tau proteins. In the pursuit of novel neuroprotective strategies, organotin(IV) compounds have garnered attention due to their unique chemical and biological properties. This study evaluates the inhibitory potential of two triphenyltin(IV) derivatives—(3-propan-1-ol)triphenyltin(IV) (Ph₃SnL₁) and (4-butan-1-ol)triphenyltin(IV) (Ph₃SnL₂)—in both free form and immobilized into mesoporous silica SBA-15~Cl, targeting acetylcholinesterase (AChE), a key enzyme involved in AD pathophysiology. The SBA-15~Cl|Ph₃SnL₂ nanostructures exhibited the most potent inhibitory activity against AChE (IC₅₀ = 0.58 μM), significantly outperforming the standard drug galantamine. Molecular docking, molecular dynamics simulations, and MM/GBSA and MM/PBSA analyses confirmed the stability and selectivity of interactions with AChE, primarily driven by hydrophobic interactions. Compound transport was also simulated using a multi-scale 3D mouse brain model to evaluate brain tissue distribution and blood–brain barrier permeability. The results highlight the strong potential of SBA-15-loaded organotin(IV) compounds as biocompatible neuroprotective agents for novel treatments of neurodegenerative diseases. Full article

The current research introduces a cost-effective thermal coating process using a tinning surfacing technique to synthesize WO₃ nanoparticle-reinforced Sn-20Bi (S20B) alloy coating on low-carbon steel (LCS). A ball-milling machine was used for mechanical mixing and blending of Sn and Bi powders together with 0.25 wt.% WO₃ nanoparticles. The produced powders were mixed with a prefabricated flux in two different ratios to optimize the best surface coating morphology. The synthesized coatings were spread out on the surface of the LCS in a layer of 0.25 g cm⁻² and were heated for 3, 4, and 5 min at 370 °C. A series of corrosion tests was carried out to understand the effect of the different S20B and S20B-WO₃ coatings on the corrosion passivation of the LCS samples in 3.5% NaCl solution. The coating surface layer thickness increased by decreasing the percentage of flux in the synthesized coating. Increasing the heating time (from 3 min to 5 min) increases surface coating uniformity and slightly boosts the average Fe−Sn intermetallic (IMC) layer thickness (from 1.7 ± 0.3 µm to 3.3 ± 0.3 µm). By incorporating 0.25 wt.% WO₃ nanoparticles into the S20B coating surface layer, a uniform microstructure was achieved and the thickness of the Fe–Sn IMC layer was reduced to 2.6 ± 0.3 µm. This study found that the presence of WO₃ nanoparticles significantly improved the corrosion resistance of S20B-coated LCS. These results demonstrate that adding a small of WO₃ nanoparticles significantly enhances the microstructural integrity and corrosion resistance of S20B coatings on LCS. Full article

The influences of the addition of Ca, Zn, and Zr on the corrosion behavior and mechanism of as-homogenized Mg-3Sn (T3) alloys in a 3.5% NaCl solution were systematically investigated via hydrogen evolution, mass loss, and electrochemical tests. The results indicated that the addition of Ca resulted in a decrease in the corrosion resistance of the T3 alloy. However, the subsequent addition of Zn and Zr could enhance the corrosion resistance of the Mg-3Sn-1Ca (TX31) alloy. The primary cause for the decline in the corrosion resistance of the TX31 alloy was that Ca altered the type of the second phase and the corrosion mechanism of the T3 alloy. This was attributed to the fact that the addition of Ca in the T3 alloy induced the precipitation of the CaMgSn phase and inhibited the precipitation of the Mg₂Sn phase. Simultaneously, both the average grain size and the area fraction of the second phase increased, which provided more initiation sites for pitting and accelerated the corrosion of the alloy. The addition of Zr in the TX31 alloy could remarkably refine grains, inhibit anodic corrosion, and improve corrosion resistance. Nevertheless, the corrosion resistance of the Mg-3Sn-1Ca-1Zr (TXK311) alloy was still inferior to that of the T3 alloy. In this study, the Mg-3Sn-1Ca-1Zn (TXZ311) alloy exhibited the best corrosion resistance, with a hydrogen-evolution corrosion rate of 2.82 mm·year⁻¹. This was because the addition of Zn refined the grains of the TX31 alloy and facilitated the formation of a relatively stable passivation film, which effectively prevented the intrusion of Cl⁻, thereby enhancing the corrosion resistance of the alloy. Full article

Salinity stress poses a major challenge to agricultural productivity worldwide, including for pumpkin, a globally cultivated vegetable crop with great economic value. To deal with salt stress, plants exhibit an array of responses such as changes in their root system architecture. However, the root phenotype and gene expression of pumpkin in response to different concentrations of NaCl remains unclear. To this end, this study evaluated the effects of salinity stress on root architecture in C. moschata (Cmo-1, Cmo-2 and Cmo-3) and C. maxima (Cma-1, Cma-2 and Cma-3), as well as their hybrids of C. moschata and C. maxima (Ch-1, Ch-2 and Ch-3) at the germination and seedling stages. The results showed that the total root length and the number of root tips decreased by more than 10% and 5%, respectively, under 180 mM NaCl conditions compared to those under the 0 mM NaCl conditions. In contrast, the total root length and the number of root tips were increased or decreased under 60 mM NaCl conditions. Meanwhile, salt stress was considered severe when treated with more than 120 mM NaCl, which could be used to evaluate the salt tolerance of the germplasm resources of pumpkin. In addition, the transcriptional changes in the roots of both Cmo-3 and Cma-2 under salt stress were analyzed via RNA-sequencing. We found 4299 and 2141 differential expression genes (DEGs) in Cmo-3 and Cma-2, respectively. Plant hormone signal transduction, Phenylpropanoid biosynthesis and the MAPK signaling pathway were found to be the significant KEGG pathways. The expression of ARF (auxin response factor), B-ARR (type-B response regulator) and PYR (pyrabactin resistance)/PYL (PYR-LIKE) genes was downregulated by NaCl treatment. In contrast, the expression of SnRK2 (sucrose non-fermenting-1-related protein kinase 2) and AHP (histidine-containing phosphotransmitter) genes was downregulated in Cmo-3 and upregulated in Cma-2. These findings will help us better understand the mechanisms of salt tolerance in pumpkins and potentially provide insight into enhancing salt tolerance in crop plants. Full article

The lactic acid (LA) production from corn stover using Lewis acid catalysts was optimized. Initially, an equimolar mixture of Al(III)/Sn(II) was used as a catalytic system at 190 °C with 5 wt% biomass. Increasing the catalyst concentration led to higher LA production, showing the optimal results at 16 mM. A low catalyst concentration mainly produced furfural and HMF, dehydration products from the corn stover sugars. Higher catalyst concentration increased LA yield but also produced the degradation of the glucose dehydration products into levulinic and formic acids, reducing LA selectivity. Al(III) was essential for LA formation, while Sn(II) was less effective due to its lower solubility, shown by the presence of Sn(II) in the solid residue after treatments. A total of 16 mM Al(III) yielded the highest LA levels at 190 °C, 7.4 g/L, and 20.7% yield. Increasing the temperature to 210 °C accelerated the LA production while also achieving the lowest energy consumption, which was 0.47 kWh/g LA at the highest LA production point. However, longer treatments at this temperature caused LA degradation. AlCl₃ has been identified as an ideal catalyst for biomass conversion to LA, being inexpensive and low in toxicity. Full article

In this paper, we investigated fractal cluster structures of colloidal particles in tin dioxide films obtained from lyophilic film-forming systems SnCl₄/EtOH/NH₄OH with different pH levels. It was revealed that at the ratio Sn > Cl₂ > O₂, N₂ = 0, and pH = 1.42, the growth of cross-shaped and flower-shaped structures of various sizes from several μm to tens of μm is observed. At the ratio Cl₂ > Sn > O₂ > N₂ and pH = 1.44, triangular and hexagonal structures are observed, the sizes of which are on the order of several tens of micrometers. The growth of hexagonal structures is probably affected by the presence of nitrogen in the film, according to the elemental analysis data. At the ratio Sn > Cl₂ > O₂ > N₂ and solution pH of 1.49, the growth of hexagonal and cross-shaped structures is observed, whereas flower-shaped structures are not observed. Hierarchical flower-like and cross-shaped structures are fractal. The shape of microstructures is directly related to the shape of the elementary cells of SnO₂ and NH₄Cl. A direct dependence of the formation of hierarchical structures on the volume of ammonium hydroxide additive was found. This allows for controlling the shape and size of the synthesized structures when changing the ratio of the initial precursors and influencing the final physicochemical characteristics of the obtained samples. Full article

The Huanggang iron-tin deposit, located in the southern Greater Khingan Range, is one of the largest Fe-Sn deposits in Northern China (NE China). Iron-tin mineralization occurs mainly in the contact zone between granitoid intrusions and the marble of the Huanggang and Dashizhai formations. Six mineralization stages are identified: (I) anhydrous skarn, (II) hydrous skarn, (III) cassiterite-quartz-calcite, (IV) pyrite-arsenopyrite-quartz-fluorite, (V) polymetallic sulfides-quartz, and (VI) carbonate ones. Fluid inclusions (FIs) analysis reveals that Stage I garnet and Stage II–III quartz host liquid-rich (VL-type), vapor-rich two-phase (LV-type), and halite-bearing three-phase (SL-type) inclusions. Stage IV quartz and fluorite, along with Stage V quartz, are dominated by VL- and LV-type inclusions, while Stage VI calcite contains exclusively VL-type inclusions. The FIs in Stages I to VI homogenized at 392–513, 317–429, 272–418, 224–347, 201–281, and 163–213 °C, with corresponding salinities of 3.05–56.44, 2.56–47.77, 2.89–45.85, 1.39–12.42, 0.87–10.62, and 4.48–8.54 wt% NaCl equiv., respectively. The H–O–C isotopes data imply that fluids of the anhydrous skarn stage (δD = −101.2 to −91.4‰, δ¹⁸O_H2O = 5.0 to 6.0‰) were of magmatic origin, the fluids of hydrous skarn and oxide stages (δD = −106.3 to −104.7‰, δ¹⁸O_H2O = 4.3 to 4.9‰) were characterized by fluid mixing with minor meteoric water, while the fluids of sulfide stages (δD = −117.4 to −108.6‰, δ¹⁸O_H2O = −3.4 to 0.3‰, δ¹³C_V-PDB= −12.2 to −10.9‰, and δ¹⁸O_V-SMOW = −2.2 to −0.7‰) were characterized by mixing of significant amount of meteoric water. The ore-forming fluids evolved from a high-temperature, high-salinity NaCl−H₂O boiling system to a low-temperature, low-salinity NaCl−H₂O mixing system. The garnet U-Pb dating constrains the formation of skarn to 132.1 ± 4.7 Ma (MSWD = 0.64), which aligns, within analytical uncertainty, with the weighted-mean U−Pb age of zircon grains in ore-related K-feldspar granite (132.6 ± 0.9 Ma; MSWD = 1.5). On the basis of these findings, the Huanggang deposit, formed in the Early Cretaceous, is a typical skarn-type system, in which ore precipitation was principally controlled by fluid boiling and mixing. Full article

In this study, we prepared an innovative corrosion-resistant and low-melting-point Al49Sn21Zn16Pb14 alloy, and its microstructure was characterized. The corrosion resistance of the Al49Sn21Zn16Pb14 alloy in a NaCl solution with different concentrations was tested via electrochemical and immersion methods. In addition, the corrosion morphologies and products were analyzed via scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD), and the effects of the NaCl solution’s concentration on the corrosion resistance of the Al49Sn21Zn16Pb14 alloy were studied. The results showed that the melting point of the Al49Sn21Zn16Pb14 alloy was only 356.8 °C, and the melting temperature range was 356.8–377.6 °C. The microstructure of the Al49Sn21Zn16Pb14 alloy was dendritic, eutectic, and peritectic, and it had a face-centered cube (FCC) composition in the solid solution phase. The dendrite structure comprised an Al-rich solid solution primarily in the interdendrites and a Zn-rich solid solution mostly in the dendrites; the eutectic structure mainly consisted of Sn- and Pb-rich solid solutions; and the peritectic structure mainly comprised Zn- and Sn-rich solid solutions. In NaCl solutions of different concentrations, the Al49Sn21Zn16Pb14 alloy is generally corrosive; the corrosion rate of the Al49Sn21Zn16Pb14 alloy in 3.5% NaCl solution was 1.97 × 10⁻² mm/a; and the corrosion surface was loose or cracking. The corrosion products attached to the corrosion surface of the alloys mainly comprised Al and Zn oxides, while Sn and Pb corroded to form Sn and Pb oxides, which dissolved or fell off to form microholes or pores on the corrosion surface of the Al49Sn21Zn16Pb14 alloy. With an increase in the NaCl solution’s concentration, the degree of corrosion products that fell off or dissolved increased, and thus, the Al49Sn21Zn16Pb14 alloy’s corrosion rate increased. In 10.5% and 14% NaCl solutions, the amount of Al oxides in the corrosion products increased, and the locally dense corrosion product that formed on the corrosion surface of the Al49Sn21Zn16Pb14 alloy cracked and could not protect the matrix. The locally dense corrosion products on the surface of the Al49Sn21Zn16Pb14 alloy in NaCl solutions therefore could not improve the corrosion resistance. Full article

With the enhancement of environmental protection awareness and the implementation of related regulations, lead-free soldering materials are gradually replacing the traditional leaded soldering materials in the field of electronics manufacturing. Sn–Ag soldering materials have become a research hotspot because of their good mechanical properties, solderability, and thermal fatigue reliability, but their high cost limits their large-scale application. The low silver content of the Sn–Ag solder reduces the cost while maintaining an excellent performance. However, as the size of electronic components shrinks and the package density increases, the solder joint spacing decreases, the potential gradient increases, and electrochemical migration (ECM) becomes a key factor affecting the reliability of solder joints. In this study, the ECM failure process was simulated by the water droplet method, and the SEM and XPS analyses were utilized to investigate the ECM mechanism of Sn1.0Ag solder alloys, and the effects of different concentrations of NaCl solutions on their ECM were investigated. The results showed that the ECM of the Sn1.0Ag solder occurred in a 0.01 M NaCl solution, the dendritic composition was pure Sn, and the white precipitate was a mixture of Sn(OH)₂ and Sn(OH)₄. With the increase in the NaCl concentration, the corrosion resistance of the Sn1.0Ag solder alloy decreases and the ECM reaction intensifies, but with a high concentration of the NaCl solution, a large amount of precipitation hinders the migration of Sn ions, resulting in the generation of no dendrites. The present study provides new insights into the ECM behavior of a low-silver-content Sn–Ag solder system. Full article

In this study, Cu-Sn alloys with varying compositions were synthesized using nickel sulfate as a structure-directing agent during electrodeposition. The crystalline structure of the alloys and the influence of nickel sulfate on the morphology were systematically investigated. The corrosion behavior of these alloys was examined in 3.5 wt.% NaCl and 0.1 M HNO₃ solutions using kinetic potential polarization and electrochemical impedance spectroscopy (EIS) techniques. X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were employed to analyze the corrosion products of the alloys. The result revealed that the absolute value of corrosion potential of Cu₄₃Sn₅₇ alloy prepared by adding nickel sulfate in 3.5 wt. % NaCl solution decreased from 0.259 V to 0.186 V, and the corrosion current density decreased from 9.456 × 10⁻⁶ mA cm⁻² to 1.248 × 10⁻⁶ mA cm⁻². In 0.1 M HNO₃ solution, the absolute values of corrosion potential of Cu₄₃Sn₅₇ alloy prepared by adding nickel sulfate decreased from 0.065 V to 0.028 V, and the corrosion current density decreased from 5.384 × 10⁻⁵ mA cm⁻² to 2.63 × 10⁻⁵ mA cm⁻². This research contributes to the understanding of how structural modification affects the electrochemical performance of Cu-Sn alloys. Full article