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The structure of calcium aluminosilicate glasses (CaO)x(Al2O3)y(SiO2)1−x−y with the near tectosilicate compositions x ≃ 0.19 and 1 − x − y ≃ 0.61 or x ≃ 0.26 and 1 − x − y ≃ 0.49 was investigated by in situ high-pressure neutron diffraction and 27Al nuclear magnetic resonance (NMR) spectroscopy. The results show three distinct pressure regimes for the transformation of the aluminum coordination environment from tetrahedral to octahedral, which map onto the deformations observed in the production of permanently densified materials. The oxygen packing fraction serves as a marker for signaling a change to the coordination number of the network forming motifs. For a wide variety of permanently densified aluminosilicates, the aluminum speciation shares a common dependence on the reduced density ρ′ = ρ/ρ0, where ρ is the density and ρ0 is its value for the uncompressed material. The observed increase in the Al–O coordination number with ρ′ originates primarily from the formation of six-coordinated aluminum Al(VI) species, the fraction of which increases rapidly beyond a threshold ρ thr ′ ∼ 1.1. The findings are combined to produce a self-consistent model for pressure-induced structural change. Provided the glass network is depolymerized, one-coordinated non-bridging oxygen atoms are consumed to produce two-coordinated bridging oxygen atoms, thus increasing the network connectivity in accordance with the results from 17O NMR experiments. Otherwise, three-coordinated oxygen atoms or triclusters appear, and their fraction is quantified by reference to the mean coordination number of the silicon plus aluminum species. The impact of treating Al(VI) as a network modifier is discussed. [ABSTRACT FROM AUTHOR]

The effect of replacing magnesia by alumina on the pressure-dependent structure of amorphous enstatite was investigated by applying in situ high-pressure neutron diffraction with magnesium isotope substitution to glassy (MgO)0.375(Al2O3)0.125(SiO2)0.5. The replacement leads to a factor of 2.4 increase in the rate-of-change of the Mg–O coordination number with pressure, which increases from 4.76(4) at ambient pressure to 6.51(4) at 8.2 GPa, and accompanies a larger probability of magnesium finding bridging oxygen atoms as nearest-neighbors. The Al–O coordination number increases from 4.17(7) to 5.24(8) over the same pressure interval at a rate that increases when the pressure is above ∼3.5 GPa. On recovering the glass to ambient conditions, the Mg–O and Al–O coordination numbers reduce to 5.32(4) and 4.42(6), respectively. The Al–O value is in accordance with the results from solid-state 27Al nuclear magnetic resonance spectroscopy, which show the presence of six-coordinated aluminum species that are absent in the uncompressed material. These findings explain the appearance of distinct pressure-dependent structural transformation regimes in the preparation of permanently densified magnesium aluminosilicate glasses. They also indicate an anomalous minimum in the pressure dependence of the bulk modulus with an onset that suggests a pressure-dependent threshold for transitioning between scratch-resistant and crack-resistant material properties. [ABSTRACT FROM AUTHOR]

Most of the available data on diffusion in natural clayey rocks consider tracer diffusion in the absence of a salinity gradient despite the fact that such gradients are frequently found in natural and engineered subsurface environments. To assess the role of such gradients on the diffusion properties of clayey materials, through-diffusion experiments were carried out in the presence and absence of a salinity gradient using salt-diffusion and radioisotope tracer techniques. The experiments were carried out with vermiculite samples that contained equal proportions of interparticle and interlayer porosities so as to assess also the role played by the two types of porosities on the diffusion of water and ions. Data were interpreted using both a classical Fickian diffusion model and with a reactive transport code, CrunchClay that can handle multi-porosity diffusion processes in the presence of charged surfaces. By combining experimental and simulated data, we demonstrated that (i) the flux of water diffusing through vermiculite interlayer porosity was minor compared to that diffusing through the interparticle porosity, and (ii) a model considering at least three types of porous volumes (interlayer, interparticle diffuse layer, and bulk interparticle) was necessary to reproduce consistently the variations of neutral and charged species diffusion as a function of salinity gradient conditions.

In this work, the Dy 2 O 3 -Al 2 O 3 -SiO 2 (DASN) and Dy 2 O 3 -Al 2 O 3 -SiO 2 -TiO 2 (DAST) glass fillers were used for joining alumina ceramic. During the cooling process of the alumina/DASN/alumina joints, Dy 2 Si 2 O 7 and Al 2 O 3 were precipitated simultaneously and gradually grown. As a result, voids were formed due to the poor flowability of the glass ceramic filler and the large density difference between the glass filler and Dy 2 Si 2 O 7 crystals. On the contrary, the addition of TiO 2 altered the sequence of the crystalline phase precipitation during the cooling process. During cooling from the joining temperature (1450 °C) to 1100 °C, only Dy 2 Si 2 O 7 was formed in the brazing seam. Simultaneously, the flowing glass phase was able to fill the spaces caused by the density differences. When the growth of Dy 2 Si 2 O 7 phase ceased, the Al 2 O 3 phase began to precipitate. Therefore, the voids caused by density differences can be eliminated in the alumina/DAST/alumina joints with high crystallinity. The optimal flexural strength of alumina/DAST/alumina joints tested at room temperature and 1000 °C reached 350 MPa and 158 MPa, respectively. [ABSTRACT FROM AUTHOR]

The applications of various clay minerals are related to their structural, physical, and chemical characteristics. These properties of the clay minerals dictate their utilization in the industries and beneficiation required before usage. The study aimed at establishing the potentiality of acid‐activated clay mineral from Hadar, Afar, Ethiopia. XRD, SEM, energy‐dispersive X‐ray fluorescence (EDXRF), and FT‐IR spectroscopies were employed to characterize the chemical compositions and interaction in the bentonite samples. The XRD results revealed that the native and activated bentonite clay contains similar minerals, such as montmorillonite (MMT) ([Ca, Na]0.33 [Al, Mg]2[Si4O10][OH]2.nH2O), quartz (SiO2), albite (NaAl2SiO6), zeolite (CaAl2O3.SiO2.nH2O), and aluminum silicate. Thus, attributes of the bentonite clay was composed of SiO2 and Al2O3 indicating that it is an aluminosilicate mineral, and the morphology of bentonite was supported by SEM. The chemical analysis by EDXRF revealed that the native bentonite (NB) consisting of 58.18 wt% (SiO2), 14.28 wt% (Al2O3), and Na2O > CaO are the major constituents of the clay with other oxides present in low amount. There was an increase in the SiO2 content in activated bentonites, and the Al2O3, Fe2O3, and MgO contents have decreased by 48.56%, 66.36%, and 84.42%, respectively. The FT‐IR spectra bands at 1627 cm−1 and 1027 cm−1 were attributed to Al–Mg–OH, Al–Al–OH, and Al–OH–O–Si stretching vibration, and the reduction of the content of the octahedral cations is accompanied by a decrease of both OH bending vibrations at 1627 and 3401 cm−1. The FT‐IR result is in clear agreement with the SEM, XRD, and EDXRF studies which indicate sequential degradation of the clay sheet upon acid treatment. Hence, rendering the activated bentonite clay of Hadar has accounted for their demand for different industrial applications such as its use as detoxifier, sealant, binder, fillers for paper, pharmaceutical products, absorbent, adsorbent, catalyst, and nanoclays. [ABSTRACT FROM AUTHOR]

This study uses coal ash obtained from the Tanjung Bin coal power plant consisting of a mixture of fly ash and bottom ash at different ratios. Such mixtures will be used with the minimum amount of Ordinary Portland Cement to stabilise marine clay. Compaction data corresponding to a mixture of coal ash and OPC mixed with marine clay soil provides 1535 and 1600 kg/ m 3 MDD and 18–22.2% OMC ranges, as additive percentages are increased. The unconfined compressive strength test indicated the highest increase at 50BA:50FA ratio with a value of 536 kPa at 15% of additive. The strength of the treated soil sample would also increase with increasing additive percentage and curing period. The XRD of untreated soil sample indicates composition intensity for minerals like quartz, mica, kaolinite, calcite, montmorillonite, and muscovite generally decreased with curing time; on the other hand, halloysite composition reduced. However, a new mineral is formed: calcium aluminium silicate hydroxide hydrate. Moreover, the FESEM results show that the treated marine clay surface particles looked denser with time. Structural voids were also reduced. In line with the XRD and FESEM test outcomes, the EDX results indicated that the formed cementitious products comprised calcium aluminate silicate hydrate. [ABSTRACT FROM AUTHOR]

By combining mechanical treatment of aluminium alloy with subsequent surface modification using micro-arc oxidation (MAO) technology, zinc oxide (ZnO) oxide coatings were prepared, which achieved enhanced hydrophobic properties, excellent antibacterial activity and corrosion resistance. The coatings were oxidised at different MAO discharge intensities using different frequencies. All surfaces were subjected to determination of wettability, corrosion resistance and chemical stability at 1, 7, 14, and 28 days and antibacterial activity of the coatings against the bacterial population of Staphylococcus aureus, Escherichia coli with an evaluation of population inhibition after 24 h. The surfaces mechanically modified by blasting showed a hydrophobic character; their subsequent oxidation by MAO contributed to a significant increase in hydrophobic properties. The sample with the highest Zn content (1.1 wt%), prepared at an MAO source frequency of 222 Hz, i.e. at the most intense plasma discharge, showed the most significant chemical stability in simulated body fluid (SBF) and distilled water and showed the highest antibacterial activity after 24 h. Thus, blasting of aluminium alloy surfaces and their subsequent MAO in alkaline electrolyte allows to obtain oxide coatings with antibacterial, hydrophobic and corrosion-resistant properties with the possibility of their use on surfaces with potential occurrence of harmful bacteria. • Oxide layers on aluminium alloy were prepared in alkaline electrolyte. • Frequencies of 49, 95 and 222 Hz, blasting and MAO technology combination were used. • Mechanically modified layers and MAO coatings achieved hydrophobic properties. • ZnO-doped MAO coatings had antibacterial properties and higher corrosion resistance. [ABSTRACT FROM AUTHOR]

Objective: To develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects. Methods: Ca-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay. Results: Ca-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively. Conclusion: A novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms. [ABSTRACT FROM AUTHOR]

Background/aim: Y2O3-Al2O3-SiO2 (YAS) glass microspheres are currently used in radioembolization treatment. However, abscess formation can occur following this treatment. This study aims to endow YAS glass microspheres with antibacterial properties to address the abscesses forming in patients after radioembolization treatment. Materials and methods: In this study, undoped YAS glass microspheres and those doped with antibacterial agents zinc (Zn) and/or copper (Cu) were successfully fabricated using a sol-gel derived method. Results: After heat treatment, the microspheres exhibited an amorphous structure. Additionally, the incorporation of Zn and/or Cu dopants did not alter the patterns observed in the X-ray diffraction analysis. Fourier transform infrared spectroscopy analysis detected Si-O-Si, Al-O-Al, and Y-O band vibrations within the structure. The presence of Zn and Cu dopants was confirmed through X-ray photoelectron spectroscopy analysis. Scanning electron microscopy revealed that all samples possessed a regular microsphere morphology, with average particle sizes ranging from 6 to 50 µm. These average particle sizes were further confirmed using a mastersizer. Conclusion: The antibacterial agent-doped YAS glass microspheres show promise in combating infections that occur following radioembolization treatment. [ABSTRACT FROM AUTHOR]

High early-strength concrete and geopolymer offer advantages of faster construction and require less curing time than traditional concrete. Bagasse ash (BA), an inert pozzolan with low reactivity in alkaline media, was activated with 10M NaOH to enhance its porosity and surface area. It was then incorporated into an 80:20 wt% mixture of metakaolin (MK) and BA to improve the early-strength properties of geopolymers. This study investigates the effects of varying amounts of activated bagasse ash (ABA) on the physical and mechanical properties of a binary MK-BA-based geopolymer. The pozzolan-to-alkali ratio was maintained at 1:1, with a difference of 10M NaOH-to-Na2SiO3. The results indicated that the compressive strength of formulation with 50 wt% ABA increased by approximately 33% compared with formulation without ABA. XRD analysis showed a sodium aluminum silicate peak at 3 days, which decreased after 28 days, confirmed by SEM/EDS. The transformation of sodium aluminosilicate gel into a dense geopolymer matrix was observed, with IR spectra demonstrating the presence of Si–O-(Si/Al) bonds contributing to high compressive strength formulations. Overall, the ABA led to the early formation of the geopolymer 3D network with high compressive strength values. [ABSTRACT FROM AUTHOR]

The objective of this study is to systematically investigate not only the influence of different additive types—beyond the much-considered case of aluminum-silicate-based additives—but also to carry out an additional comparison between primary and secondary emission mitigation measures during small-scale wood-chip combustion. Hence, combustion trials are realized within a 33-kW combustion plant. Pine wood chips additivated with 1.0 wt%a.r. of four additives have shown promising emission reduction effects in the past; namely kaolin (i.e., aluminum-silicate-based), anorthite (i.e., aluminum-silicate- and calcium-based), aluminum hydroxide (i.e., aluminum-based), and titanium dioxide (i.e., titanium-based). In addition to the primary mitigation measure (i.e., (fuel) additivation), an electrostatic precipitator (ESP) as a common secondary mitigation measure for total particulate matter (TPM) reduction is used for comparison. In addition to standard analyses (e.g., gravimetric determination of TPM emissions), an extended methodology (e.g., characterization of the elemental composition and ultrafine particle fraction of TPM emissions) is applied. The results show that the additivation of wood chips with kaolin and anorthite can lead to an operation of the combustion plant in compliance with the German legal TPM limit values by undercutting the absolute emission level achievable by the ESP. Additionally, kaolin and anorthite achieve significant reductions in carbon monoxide (CO) emissions, while kaolin simultaneously, and similarly to ESP, also leads to a shift in the particle size number distribution of PM emissions towards coarser particles. All additives show a significant reduction of potassium (K) emissions by the formation of high-temperature stable K compounds in the resulting ashes. [ABSTRACT FROM AUTHOR]

Supersulfated cements (SSCs), as potential green alternatives to Portland cements, are in demand for developing new kinds of precursors instead of blast-furnace slag. A mixture of kaolin, quartz and sodium hydroxide was calcined to prepare SSC by grinding clinkers with lime and gypsum. Preparation factors were investigated and multiple characterisation methods were adopted to explore the calcination and hydration mechanisms. The sodium hydroxide additive was found to reduce the activation temperature of the kaolin and a moderate addition of sodium hydroxide improved the compressive strength of SSC made from calcined kaolin. Quartz added into the kaolin calcined with a moderate amount of sodium hydroxide also promoted the compressive strength. Comprehensive characterisations indicated that the alkali-added calcination of the kaolin generated pozzolanic zeolite and sodium aluminosilicates along with inert nepheline at a calcination temperature ≤950°C. The hydration of SSC pastes tended to produce C(N)–A–S–H/N(C)–A–S–H gels and crystalline ettringite. During sodium hydroxide-added calcination, quartz added into the kaolin hindered the generation of inert nepheline and produced cementitious N–S gels. The research facilitates the utilisation of the massive discharged coal gangues rich in kaolinite and quartz by synthesising SSCs economically. [ABSTRACT FROM AUTHOR]

Dephosphorization is essential for utilizing high-phosphorus iron ore (HPIO), and this work prepared reduced iron powder via reductive roasting in a semi-industrial rotary kiln follower by magnetic separation. Under the conditions, reductive temperature of 1150°C, duration time of 60 min, mass ratio of briquettes to pea coal of 1:1, the reduced iron powder with an iron grade of 93.21% and phosphorus content of 0.13% was obtained, of which the corresponding iron recovery is 82.68% and dephosphorization ratio is 89.87%. The limestone reacted with gangue to form calcium aluminum silicate, preventing the reduction of phosphorate and in turn the formation of ferrophosphorus. [ABSTRACT FROM AUTHOR]

In this paper, high transmittance glass-ceramics containing Zirconium Yttrium Oxide (Zr 0.82 Y 0.18 O 1.91) nanocrystals were successfully prepared by melt cooling and crystallization heat-treatment method. The effects of Y 2 O 3 concentration on the structure, crystallization performance, transmittance, and indentation fracture toughness of Na 2 O–Al 2 O 3 –B 2 O 3 –SiO 2 –ZrO 2 glass and glass-ceramics were explored. The addition of Y 2 O 3 improved the Vickers hardness (4.81 GPa–5.25 GPa) and indentation fracture toughness (0.78 MPam1/2 to 0.95 MPam1/2) of the glasses. Y 2 O 3 successfully facilitated the precipitation of the non-alkaline crystalline phase Zr 0.82 Y 0.18 O 1.91 at low heat-treatment temperatures. The precipitation of Zr 0.82 Y 0.18 O 1.91 nanocrystals improves the Vickers hardness (5.17 GPa–5.56 GPa) and indentation fracture toughness (0.90 MPam1/2 to 1.01 MPam1/2) in glass-ceramics, while concurrently preserving a high level of visible light transmittance (∼90 %). This demonstrates its potential applications in the field of protective covers for electronic displays. [ABSTRACT FROM AUTHOR]

This research investigates the potential of using nanoparticles, Poly Aluminum Silicate and Poly Calcium Silicate, and industrial by-products, Recycled Glass Powder (RGP) and Ground Granulated Ballast Furnace Slag (GGBS) to enhance the durability and strength of a sandy soil, particularly in wet or saturated conditions where water table is close to building foundations. The study aims to determine the optimal content and concentration of additives and assess their influence on the compressive strength and the failure strain. The optimal content and concentration of dry additives and alkaline solutions were determined. Uniaxial compressive strength tests were conducted on various stabilized geopolymers, considering factors such as alkaline activator type, nanoparticle type and percentage, and degree of saturation. Scanning electron microscopy images were taken and analyzed to verify geomechanical testing outcomes. Mixtures with nanomaterials exhibited greater strength than untreated soil, with some exhibiting up to a tenfold increase. GGBS-based samples displayed a twofold increase in strength with nanomaterial addition, while RGP-based samples experienced reduced strength. However, both nanomaterials addressed the durability concerns in wet conditions. The addition of 2% nanomaterials to GGBS-based mixtures led to significant strength gains, with some showing a 20% increase after saturation. This research indicated the potential of nanoparticles and industrial by-products in resolving a major concern regarding geopolymers which is the lack of durability in wet or saturated conditions. These findings have implications for eco-friendly geoconstruction materials and practices. [ABSTRACT FROM AUTHOR]

To solve the problem of carbon emissions and pollution of traditional cement, composite geopolymer based on alkali-stimulated slag powder and fly ash was used to solidify loess. The effects of the alkali activator content, the ratio of NaOH to alkali activator, and the ratio of slag powder to silicon-aluminum (Si-Al) raw material on the unconfined compressive strength (UCS) of solidified loess were investigated through different tests. Then, the results from microscopic tests such as scanning electron microscopy (SEM), x-ray diffraction (XRD), and mercury intrusion porosimetry (MIP), as well as the variation results of the UCS, were used to analyze the influencing mechanism of the three factors on the solidified loess. The test results showed that the UCS of the slag powder– and fly ash–based composite geopolymer solidified loess first increased and then decreased with the increasing alkali activator content, and the UCS of the solidified loess also first increased and then decreased with the ratio of NaOH to alkali activator. The UCS increased as the ratio of slag powder to Si-Al raw material increased. The reaction of composite geopolymer solidified loess produces amorphous hydrated calcium silicate hydrates (C─ S─ H), calcium aluminum silicate hydrates (C─ A─ S─ H), and sodium-based aluminosilicate (N─ A─ S─ H) gels. These gels effectively bond and fill the soil particles, leading to a decrease in the number of macropores and total pores in the soil. As a result, the soil becomes more compact and increases the UCS of solidified loess. The results of this study provide a certain basis for engineering applications of the composite geopolymer to solidify loess based on slag powder and fly ash. [ABSTRACT FROM AUTHOR]

The corrosion of SiCf/SiC composites in gas environment threatens their long‐term service in aeroengines as hot‐end structure components. Addition of corrosion‐resistant phases into SiC matrix is a potential strategy to improve the service performance of SiCf/SiC materials. Here, AlN added SiC ceramics were prepared by reactive melt infiltration, and the effect of AlN phase on the oxidation resistance of the ceramics was emphasized. The oxidation tests were performed in dry oxygen and water oxygen atmospheres at 1100°C–1300°C, respectively. The oxidation mechanism was discussed based on the microstructure evolution of the oxide layer. The results show that the oxide layer is composed of aluminum silicate glass and Al2O3 flakes dispersedly distributed in the glass phase. As the temperature rises, the oxide layer gradually grows and thickens. Finally, a smooth and dense protective layer could be formed on the surface of ceramics to resist oxidation. This study can provide a profound insight to construct SiCf/SiC composites with excellent oxidation resistance. [ABSTRACT FROM AUTHOR]

LAS glass-ceramics stimulate considerable attention in academic and industrial fields due to exceptional properties, such as low thermal expansion coefficient, transparency or superior mechanical strength. We report here an experimental investigation of LAS structure and microstructure using conventional techniques as XRD or S/TEM, but also an innovative technique based on electron diffraction mapping. The later gives a topography of the sample and a clear picture of the distribution between the glass and the spodumene particles. All the data converge towards a model of hard spheres where 75 % of the volume is composed of spheroid particles and 25 % of the remaining volume is composed of glass, which is present in the inter-particle interstices. These findings provide a new knowledge about the LAS system and may offer useful guidance for other researchers in ceramic community. [ABSTRACT FROM AUTHOR]

Crystalline zeolites have high acidity but limited utility due to microporosity, whereas mesoporous amorphous aluminosilicates offer better porosity but lack sufficient acidity. In this work, we investigated defect engineering to fine-tune the acidity of amorphous acidic aluminosilicates (AAS). Here we introduced oxygen vacancies in AAS to synthesize defective acidic aluminosilicates (D-AAS). 1H, 27Al, and 17O solid-state nuclear magnetic resonance (NMR) studies indicated that defects induced localized structural changes around the acidic sites, thereby modifying their acidity. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy studies substantiated that oxygen vacancies alter the chemical environment of Brønsted acidic sites of AAS. The effect of defect creation in AAS on its acidity and catalytic behavior was demonstrated using four different acid-catalyzed reactions namely, styrene oxide ring opening, vesidryl synthesis, Friedel-Crafts alkylation, and jasminaldehyde synthesis. The defects played a role in activating reactants during AAS-catalyzed reactions, enhancing the overall catalytic process. This was supported by in-situ FTIR, which provided insights into the molecular-level reaction mechanism and the role of defects in reactant activation. This study demonstrates defect engineering as a promising approach to fine-tune acidity in amorphous aluminosilicates, bridging the porosity and acidity gaps between mesoporous amorphous aluminosilicates and crystalline zeolites. Is it possible to fine-tune the acidity of amorphous aluminosilicates? Here authors use defect engineering as a method to optimize acidity, bridging the porosity and acidity gaps between amorphous aluminosilicates and crystalline zeolites. [ABSTRACT FROM AUTHOR]

Benefiting from high safety, low cost, and competitive energy density, aqueous zinc ion batteries (AZIBs) have emerged as very promising technology for grid energy storage. However, the lifetime of AZIBs is severely affected by uncontrolled zinc dendritic growth and undesirable side reaction. To address the problem, natural aluminum silicate hydroxide covered glass fibers separator (AlSi‐GF) is prepared herein using a simple spraying method. Aluminum silicate hydroxide is a complex oxide, where a large number of adsorption sites can adsorb Zn2+ and guide its deposition process. In particular, the Maxwell–Wagner polarization of aluminum silicate hydroxide under an applied electric field contributes to homogenizing the electric field distribution around the interface, thereby modulating zinc deposition and reducing the nucleation overpotential. Impressively, AlSi‐GF separator enables high‐performance zinc‐metal batteries. The symmetric battery with AlSi‐GF separator has a stable voltage polarization and an ultra‐long cycle life of 2280 h at a current density of 1 mA cm−2, and the Zn//V2O5 full cell based on AlSi‐GF separator can exhibit a high specific capacity of 123 mAh g−1 after 1500 cycles at 1 A g−1. This study provides new insights into the design of reliable and cost‐effective separators for metal anodes in energy storage devices. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the feasibility of monolithic zirconia laminate veneers (MZLV) compared to lithium disilicate laminate veneers (LDLV). Materials and methods: Sixty resin replicas, each prepared with depths of 0.5 mm, 0.7 mm, and 1 mm, were produced using a 3D printer from acrylic teeth. Laminate veneers of these thicknesses were milled from pre-sintered monolithic zirconia (3rd generation) and lithium disilicate blocks. The intaglio surface of MZLV was treated with air abrasion using 110 μm diameter silica-modified aluminium oxide particles and ceramic primer, while LDLV was etched with etchant gel and treated with the ceramic primer before cementation with resin cement. Vertical marginal discrepancy (VMD) was assessed using a stereomicroscope, and a load-to-failure test was conducted using a universal testing machine. Failure modes were evaluated macroscopically on fractured surfaces. Data were analysed statistically using Two-way ANOVA and Bonferroni correction (α = 0.05). Results: LDLV samples exhibited significantly larger VMD compared to MZLV samples across all thicknesses, especially in cervical, palatal, and mean data. Within the LDLV group, load-to-fracture values for 0.7 mm and 1.0 mm thicknesses were similar, whereas for 0.5 mm thickness, it was significantly lower. In the MZLV group, load-to-fracture values were lower for 0.7 mm and 1.0 mm thicknesses compared to LDLV, but higher for 0.5 mm thickness. Conclusions: Material choice and restoration thickness significantly influence laminate veneer restorations' success. MZLV generally exhibits superior vertical marginal fit compared to LDLV, with varying load-to-failure values across different thicknesses. Clinical management of debonding in MZLV is simpler compared to restoration fracture in LDLV. Clinical relevance: Considering clinical factors, MZLV may be a preferable option to LDLV for this restoration with the thickness of 0.5 mm. [ABSTRACT FROM AUTHOR]

Nanotechnology can contribute significantly to the aquaculture sector for a wide range of applications. In this study, silica nanoparticles were prepared from beach sand and characterized. The XRD pattern was obtained and confirms the crystalline nature of potassium aluminium silicate [K(AlSi3O8)], sodium silicate (Na2Si2O5), and silicon dioxide (SiO2). FTIR confirms that intense peaks at 445, 795, and 1036 cm−1 are characteristic of Si–O–Si stretching vibration. TEM micrograph of silica nanoparticles found a spherical morphology with an average size of 42 nm. In vitro anti-WSSV (white spot syndrome virus) activity was carried out using PmLyo-Sf9 cells by attachment inhibitory and virucidal activity; the optimum concentration was determined as 320 μg/mL. The interaction of silica nanoparticles and VP28 envelope protein was confirmed using in silico approach. The complexes K(AlSi3O8)-VP28, Na2Si2O5-VP28, and SiO2-VP28 had binding affinities of −5.2, −7.2, and −8.3 Kcal/mol, respectively. [ABSTRACT FROM AUTHOR]

We use post Hartree–Fock advanced electronic structure computations to investigate the lowest electronic states of the AlO3+ trication. These computations confirm the existence of metastable AlO3+ ions in gas phase. At least three electronic states (13Π, 11Δ, 11Σ+) with potential wells are identified. These potential wells have depths of several hundreds of meV, which are deep enough to support several rovibrational levels where this trication may be found. Besides, we estimate the adiabatic triple ionisation energy of AlO at ∼55 eV. Furthermore, the current confirmation of the meta-stability of AlO3+ in gas phase should motivate the search for this aluminium oxide with Al(+V) in liquids and in solid state, in particular at high-pressure/high-temperature phases of alumina polymorphs and of aluminosilicates. [ABSTRACT FROM AUTHOR]

The materials used in concentrating solar power (CSP) systems are becoming of interest because of the high energy efficiency of energy storage. Molten salts can be used as both heat-storage media and heat-transfer fluid in a CSP system. In molten salts, steel alloys used in vessels and pipelines are highly vulnerable to hot corrosion. To protect steel alloys, applying a coating is an excellent strategy to extend the life of the alloy. NiCrAl coatings are well-suited for high-temperature environments. The purpose of this study was to investigate the corrosion behavior of NiCrAl with Si addition coatings on AISI304 in molten salt. NiCrAl coatings with and without Si addition were deposited using the high-velocity oxygen fuel (HVOF) technique. The corrosion test was performed using an immersion test in modified solar salt with 0.5% NaCl at 400–600 °C. Gravimetric methods evaluate the weight change for immersion tests. At 400 °C, an increased amount of weight gain due to the oxidation reaction and molten salt infiltration was observed. At 600 °C, the corrosion reaction was more dominant, and apparent oxidation was decreased; however, oxidation products NiO and sodium aluminum silicate were detected. Si addition supports the formation of the protective oxide sodium aluminum silicate, which inhibits molten salt oxidation reaction and molten salt infiltration. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of calcined clay as supplementary cementitious material on thermogravimetric analysis and compressive strength. Thai iron-rich Lopburi calcined clay was used as Portland cement replacement in the study at 5%, 10%, 15% and 20% by mass. Mortar and paste samples were water cured for 3, 7 and 28 days. The results showed that compressive strength increased when replacement level of Portland cement with calcined clay increased. The change in compressive strength with calcined clay content is discussed in relation to the acceleration in Portland cement hydration and pozzolanic reaction. Thermogravimetric analysis detected many phases such as calcium silicate hydrate (C–S–H), calcium aluminum silicate hydrate (C–A–S–H), monocarboaluminate and hemicarboaluminate hydrate, calcium hydroxide (Ca(OH)2) and calcium carbonate (CaCO3). In addition, thermogravimetric analysis showed the most hydration products which enhance the compressive strength such as C–S–H and C2ASH8 were found in the 20% calcined clay mix. [ABSTRACT FROM AUTHOR]

The periparturient period is characterized by the increased demand for calcium (Ca) in dairy cows. This has resulted in the use of several different prepartal nutritional strategies to prevent hypocalcemia postpartum. The objective of our study was to determine the effects of feeding synthetic zeolite A (XZ), a diet with negative dietary cation-anion difference (−DCAD), or a positive-DCAD diet (CON) during the close-up period on peripartal mineral dynamics and hormones involved in calcium metabolism. To this end, 121 multiparous Holstein cows, blocked by lactation number and expected due date, were enrolled at 254 d of gestation and randomly assigned to 1 of 3 prepartum diets: CON (+190 mEq/kg; n = 40), −DCAD (−65 mEq/kg; n = 41), or a diet supplemented with sodium aluminum silicate (XZ; +278 mEq/kg, fed at 3.3% DM, targeting 500 g/d; n = 40; Protekta Inc.). Blood, urine, and saliva samples were collected from enrollment until parturition, with data analyzed and presented beginning 14 d before parturition (d −14) until parturition (d 0), and on d 1, 2, 3, 6, 9, 12, 15, 18, 21, 35, and 49 postpartum, to assess mineral and hormone dynamics. Total fecal collections were performed in a subset of 8 cows per treatment group to assess fecal mineral loss. Data were analyzed as a randomized complete block design in SAS. Cows fed XZ and −DCAD had higher blood Ca concentrations compared with CON-fed cows, with XZ-fed cows exhibiting the highest blood Ca concentrations pre- and postpartum. Cows fed XZ had decreased blood and salivary phosphorus (P), increased fecal water-extractable phosphate, and the highest blood calcium concentrations pre- and postpartum. Parathyroid hormone was unaffected by diet but was increased at parturition in all treatments. Serotonin concentrations were increased in −DCAD and XZ cows compared with CON during the prepartum period. Our data indicate that the XZ group's improvement in blood Ca concentrations pre- and postpartum is most likely regulated by a dietary P restriction. Taken together, these data suggest that XZ and −DCAD diets improve postpartum calcium metabolism; however, they appear to work through different mechanisms. [ABSTRACT FROM AUTHOR]

The objectives of this study were to assess the effects of feeding 2 different diets, a diet with low dietary cation-anion difference (DCAD) or a diet with synthetic zeolite A, to multiparous Holstein cows during the close-up period on dry matter intake (DMI) and energy metabolism, as well as to evaluate colostrum and milk production. A total of 121 multiparous Holstein cows, blocked by lactation number and expected parturition date were enrolled at 254 d of gestation and randomly assigned to 1 of 3 dietary treatments: control (CON; +190 mEq/kg; n = 40), negative DCAD (−DCAD, −65 mEq/kg; n = 41; Ultra Chlor; Vita Plus, Lake Mills, WI), or a diet containing sodium aluminum silicate zeolite (XZ; +278 mEq/kg, fed at 3.3% dry matter, targeting 500 g/d; n = 40; X-Zelit, Protekta Inc., Lucknow, ON, Canada/Vilofoss, Graasten, Denmark). Prepartum DMI was measured daily using Insentec roughage intake control (RIC) gates (RIC System, Holofarm Group, the Netherlands). All cows received the same postpartum diet. Blood and urine samples were collected daily beginning 14 d before parturition (d −14) until parturition (d 0), and on 1, 2, 3, 6, 9, 12, 15, 18, 21, 35, and 49 d postpartum. Colostrum collected within 6 h of parturition, weighed, and based on samples' Brix value, IgG concentrations, and nutrient composition were analyzed. Prepartum, cows fed the XZ diet had decreased DMI (11.70 ± 0.26, 13.88 ± 0.26, and 13.45 ± 0.25 kg/d for XZ, CON, and −DCAD, respectively) and lower rumination (487 ± 8.1, 531 ± 8.3, and 527 ± 8.5 min for XZ, CON, and −DCAD, respectively) compared with CON and −DCAD. However, rumination was not different postpartum due to treatment. No prepartum or postpartum differences were observed for glucose or BHB concentrations in blood between dietary treatments. Colostrum collected from cows fed XZ had the highest IgG concentrations (91.10 ± 2.63, 78.00 ± 2.63, and 78.90 ± 2.63 mg/mL for XZ, CON, and −DCAD, respectively), but yield did not differ between dietary treatments. Additionally, cows in their third lactation or greater fed XZ had the highest milk production (51.0 ± 1.1 kg) during the first 49 d in milk. This study demonstrates that despite a decrease in DMI and rumination in cows fed XZ prepartum, blood BHB concentrations were not altered. Additionally, cows fed XZ had higher colostral IgG concentrations and cows in their third lactation or greater fed XZ produced the most milk. These data suggest that feeding XZ prepartum may improve colostrum quality and milk yield in mature cows, and does not affect energy metabolism. [ABSTRACT FROM AUTHOR]

Fibers crystallize and become brittle at high temperatures for a long time, so the surface coating must maintain long-lasting emission performance, which requires superior antioxidant properties of the high-emissivity fillers. To improve the radiation performance of the coating and the tensile strength of the fiber fabric, a double-layer coating with high emissivity was prepared on the surface of flexible aluminum silicate fiber fabric (ASFF) using MoSi2 and SiC as emissive agents. The incorporation of borosilicate glass into the outer coating during high-temperature oxidation of ZrB2 results in superior encapsulation of emitter particles, effectively filling the pores of the coating and significantly reducing the oxidation rate of MoSi2 and SiC. Furthermore, the addition of an intermediate ZrO2 layer enhances the fiber bundle's toughness. The obtained double-coated ASFF exhibits an exceptionally high tensile strength of 57.6 MPa and a high bond strength of 156.2 kPa. After being subjected to a 3 h heating process, the emissivity exhibits a minimal decrease of only 0.032, while still maintaining a high value above 0.9. The thermal insulation composites, consisting of a flexible ASFF matrix and a ZrB2-modified double-layer coating, exhibit significant potential for broad applications in the field of thermal protection. [ABSTRACT FROM AUTHOR]

Barium–strontium aluminosilicate (BSAS), with excellent resistance to water vapor corrosion and low water permeability, is considered an ideal environmental barrier coating material. Water vapor plays an important role on the failure of BSAS when it is exposed to service environments. Herein, the atomic transport properties of water in BSAS are investigated using ab initio calculations. The metastable structure of water in BSAS mainly consists of hydroxyl group and H+, where the hydroxyl group mainly exists in the form of Al–OH structure. In BSAS crystals, water first reacts with the aluminosilicate network to form metastable hydroxyl group and H+, and then hydroxyl group and H+ diffuse through the aluminosilicate network. Alkaline earth elements limit the diffusion behavior of water and improve the resistance to water vapor corrosion by maintaining the desired local charge balance of the Al–O4 tetrahedron structure. Furthermore, the ab initio molecular dynamics calculations at service temperature and pressure of BSAS are carried out to verify the above conclusions. [ABSTRACT FROM AUTHOR]

Context.--Overexposure to respirable coal mine dust can cause severe lung disease including progressive massive fibrosis (PMF). Field emission scanning electron microscopy with energy dispersive x-ray spectroscopy (FESEM-EDS) has been used for in situ lung dust particle analysis for evaluation of disease etiology. Automating such work can reduce time, costs, and user bias. Objective.--To develop and test an automated FESEMEDS method for in situ analysis of inorganic particles in coal miner lung tissue. Design.--We programmed an automated FESEM-EDS procedure to collect particle size and elemental data, using lung tissue from 10 underground coal miners with PMF and 4 control cases. A statistical clustering approach was used to establish classification criteria based on particle chemistry. Data were correlated to PMF/non-PMF areas of the tissue, using corresponding brightfield microscopy images. Results for each miner case were compared with a separate corresponding analysis of particles recovered following tissue digestion. Results.--In situ analysis of miner tissues showed higher particle number densities than controls and densities were generally higher in PMF than non-PMF areas. Particle counts were typically dominated by aluminum silicates with varying percentages of silica. Compared to digestion results for the miner tissues, in situ results indicated lower density of particles (number per tissue volume), larger size, and a lower ratio of silica to total silicates-- probably due to frequent particle clustering in situ. Conclusions.--Automated FESEM-EDS analysis of lung dust is feasible in situ and could be applied to a larger set of mineral dust--exposed lung tissues to investigate specific histologic features of PMF and other dust-related occupational diseases. [ABSTRACT FROM AUTHOR]

Epoxy film adhesives are typically used in different industries. However, these adhesives suffer from brittleness, low flexibility, and thermal stability problems. In this research, phenolic resin (Novolac) and poly (butyl acrylate‐block‐styrene) were used in the formulation of epoxy film adhesive (Diglycidyl ether bisphenol A) to increase thermal stability and adhesion strength and as the toughening agent, respectively. Alumina nanoparticles were also employed to enhance the mechanical properties. The influence of block copolymer and alumina nano particles was also assessed on the mechanical and thermal properties of epoxy‐based film adhesives. The investigation of the mechanical properties of dumbbell‐shaped samples and adhesion strength of the Al‐Al bonded joints were evaluated by tensile, lap shear, and T‐peel tests. The thermal stability of the optimal samples was assessed by thermogravimetry analysis (TGA). SEM analysis was also utilized to study the toughening mechanism. Tensile test of the dumbbell‐shaped samples indicated that the incorporation of 2.5 phr block copolymer and 2 phr alumina nanoparticles enhanced the toughness to 250%. The shear and peel strengths of this sample also exhibited 51% and 76% increase, respectively, showing a remarkable synergistic effect. On the other hand, TGA results revealed that the incorporation of block copolymer improved the thermal stability of the adhesive matrix. The copresence of these two materials also showed a considerable synergistic effect on the thermal stability. The SEM results were also in line with the results of mechanical tests as the crack deviation, crack pinning, and debonding were the most important mechanisms of toughening. Highlights: A new platform was developed for designing epoxy films adhesives with high mechanical, adhesion, and thermal properties.The hybrid of butyl acrylate block styrene copolymer, phenolic resin, and alumina nanoparticles showed synergistic effects on the lap shear and T‐peel strength.The greatest improvement in toughness was related to the epoxy adhesive containing 2.5 phr block copolymer and 2 phr alumina nanoparticles.Analysis of the fracture surface showed that by using hybrid of nanoparticles and block copolymers in the epoxy film adhesive formulation, the cohesive failure occurred.The use of hybrid additives in film adhesive formulations enlightened manufacture of adhesives for future studies on adhesive formulations. [ABSTRACT FROM AUTHOR]

In Afghanistan, groundwater is widely used for drinking water, but its quality poses a health threat. This study investigates the physical, chemical, and bacteriological characteristics of groundwater in the Upper Kabul Sub-basin. Fifteen samples were collected and analyzed from different parts of the study area. The qualitative determination of parameters such as pH, Electrical conductivity (EC), Total dissolved solids (TDS), Salinity, Total hardness, Calcium, Magnesium, Sodium, Chloride, Fluoride, Sulfate, Phosphate, Potassium, Nitrite, Nitrate, Ammonia, Iron, Manganese, Copper, Aluminum, Arsenic, Total coliform, and Fecal coliform bacteria was carried out. The results were compared with WHO and ANSA standards to assess their suitability for drinking purposes. The analyzed samples indicate that physical parameters generally fall within permissible limits according to WHO and ANSA standards. However, certain wells exhibited elevated levels of chemical and bacteriological contaminants. Specifically, Magnesium concentrations exceeded the WHO guideline of 30 mg/L in all of the samples, and Calcium levels surpassed the recommended limit of 75 mg/L in 53% of the samples. Total coliform bacteria were detected in 33.33% of the samples, while fecal coliform bacteria were within the WHO and ANSA permissible limit for drinking water. The Pearson's correlation coefficient (R) suggested significant correlations between EC, TDS, and total hardness with other physical and chemical parameters. For instance, EC showed a strong positive correlation (R = 1.00) with TDS, EC and Salinity (R = 0.981), EC and Fluoride (R = 0.838) EC and Sulfate (R = 0.853), TDS and Salinity (R = 0. 981), TDS and Fluoride (R = 0.838), TDS and Sulfate (R = 0.853). The findings demonstrate that correlation coefficient analyses of water quality parameters provide a valuable means for monitoring water quality. These results offer critical insights for ensuring a safe water supply in the region. [ABSTRACT FROM AUTHOR]

Foam-forming technique imparts ceramic fiber paper with excellent uniformity, low density, and high porosity, but its strength loss must be compensated. Herein, a flexible and rigid foam-formed ceramic fiber network was manufactured by using different strength improvement methods and simultaneously investigated their strength and thermal insulation properties. Sufficient strength (1136 kPa) was achieved by combining Polyvinyl alcohol (PVA) 2 % and Polyester (PET) 3 %. However, the tensile strength of fiber networks would decrease under the contribution of inter-fiber bonding area reduced when the fiber length was longer than 24 mm. Benefiting from the developed flocculation system (aluminum sol-anionic polyacrylamide-carboxymethylcellulose), the strength of the foam-formed ceramic fiber network was 20 kPa, the retention rate increased from 75 % to 88 %, and the average aggregation factor of fillers in the Z direction was 0.67. By adjusting the ratio and Z-directional distribution of functional fillers, the sintered foam-formed paper with a tensile strength of 1300 kPa and compressive strength of 1000 kPa could be obtained. The thermal insulation performance (thermal conductivity 0.03252 W/(m·K)) was similar to the quartz fiber paper reinforced silica airgel, and the flame resistance was better than the commercialized aluminum silicate wool board. [ABSTRACT FROM AUTHOR]

This research focuses on the utilization of recently investigated aluminosilicate industrial wastes as precursors to produce non-structural precast alkali-activated concrete pavement blocks. For this purpose, conventional blocks (200 mm × 100 mm × 80 mm) were produced using electric arc furnace slag and municipal solid waste incineration bottom ashes as the sole binders. Portland cement and fly ash blocks were produced as references. The blocks underwent a curing regimen comprising thermal, dry, and carbonation curing stages. Control uncarbonated specimens were subjected to dry curing instead of CO2-based curing to evaluate the influence of carbonation on the blocks' strength development. The specimens were subsequently examined following EN 1338, which is the European standard for assessing and ensuring the conformity of conventional concrete pavement blocks. The carbonated blocks revealed improved mechanical and physical properties in relation to the uncarbonated ones. All blocks met standard dimensions, showed minimal skid potential (most indicating extremely low potential for slip for reporting unpolished slip resistance values exceeding 75), and had enhanced abrasion resistance due to carbonation, showing 30% and 11% less volume loss due to abrasion for fly ash and bottom ash, respectively. Carbonated blocks performed better than non-carbonated ones, displaying lower water absorption (0.58% and 0.23% less water absorption for bottom ash and slag, respectively) and higher thermal conductivity (20%, 13%, and 8% increase in values for fly ash, slag, and bottom ash, respectively). These results confirm the effectiveness of the accelerated carbonation curing technique in improving the block's performance. Despite the promising outcomes, further optimization of the alkaline solution and carbonation curing conditions is recommended for future research. [ABSTRACT FROM AUTHOR]

Five phyllosilicates (kaolinite, montmorillonite, saponite, sepiolite and palygorskite) have been selected as starting materials for the synthesis of zeolites. Among them, kaolinite and montmorillonite display the lowest Si/Al molar ratio leading to aluminosilicates with high crystallinity. Thus, the hydrothermal treatment under basic conditions forms 4A zeolite when kaolinite is used as starting material while 13X zeolite is obtained when montmorillonite is used as starting material. The microporosity and CO2-adsorption capacity of the prepared zeolites are directly related to its crystallinity. Thus, in order to improve it, raw phyllosilicates were subjected to a microwave-assisted treatment to remove undesired Mg or Fe-species, which have a negative effect in the assembling of the zeolites by hydrothermal basic conditions in a second step. The highest adsorption value was 3.85 mmol/g at 25 °C and 760 mm of Hg for Mont-A-B sample after the consecutive treatments. [ABSTRACT FROM AUTHOR]

Geopolymers exhibit broad application prospects, including construction and radiation shielding, which require excellent mechanical performances. However, investigations on the nature of geopolymerization reactions and their consequential impact on mechanical performance are still vague. In this study, the effect of the major factors of Si/Al ratio and curing time on the geopolymerization reaction and flexural strength were studied based on the microstructure evolution and chemical bonding formation analyzed using the SEM, FTIR, peak deconvolution, and XRD methods. The microstructure of geopolymers was transferred from initially layered smooth particles of kaolinite to a 3D network porous structure, corresponding to sodalite. A spectrum exclusive to the geopolymer structure occurred at 973 cm−1, corresponding to the sodium aluminum silicate hydrate (N-A-S-H) links, the integral area of which represents the degree of geopolymerization reaction. Furthermore, a controllable reaction degree was achieved by adjusting the Si/Al ratio and curing time, where the maximum reaction degree of 55% was achieved at a Si/Al ratio of 1.94 when cured for 7 d. The correlation between the flexural strength and reaction degree was found to follow a proportional relationship, achieving a flexural strength of 21.11 MPa with a degree of 45%. This study provides insight into the development of mechanical strength through controlling the reaction process. [ABSTRACT FROM AUTHOR]

Ceramic coatings were obtained by micro‐arc oxidation (MAO) on the surface of AA1060 pure aluminum in alkaline silicate electrolyte with the addition of graphene. The effects of graphene contents in the range of 0–.30 g/L in the electrolyte on surface morphology, corrosion resistance, and wear resistance of the ceramic coatings were investigated. The outer surface structure, outer surface element content, coating cross‐section structure, coating cross‐section element content, coating/substrate interface structure, and coating phase were characterized by scanning electron microscope and X‐ray diffraction. Potentiodynamic polarization and electrochemical impedance spectroscopy were used to evaluate the corrosion behavior of MAO samples in a 3.5‐wt% NaCl solution. In addition, the resistance to sliding and abrasive wear of the oxide coating were studied experimentally. The results show that the alkaline silicate electrolyte with the addition of graphene has a significant effect on the characteristics of MAO coating. The performance of micro‐arc oxide coatings is best when the graphene content in the electrolyte is.15 g/L, the average thickness of the film is 7.24 μm, the average pore size is 6.07 μm, the impedance value is approximately 4.01 × 106 Ω, and its friction coefficient is.55. [ABSTRACT FROM AUTHOR]

High flame retardancy, satisfactory mechanical properties are crucial for polymeric composites employed in fields with safety requirements. Inorganic fillers can effectively regulate the structure and composition of polymeric materials and have become an effective strategy for fabricating high-performance polymeric composites. Herein, aluminum phosphate–coated sepiolite (Sep@AlPO4) fillers are fabricated as a multifunctional additive to modify polyethylene oxide (PEO), PEO nanocomposites were prepared via incorporation of Sep@AlPO4 and phenethyl-bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative (DiDOPO) in the PEO matrix, and the synergistic effects between Sep and AlPO4 are discussed. The results reveal that Sep@AlPO4 could simultaneously enhance the flame retardancy and strengthen the mechanical properties of PEO/DiDOPO. Additionally, Sep@AlPO4 could increase the viscosity, storage modulus, and loss modulus of the composites. This study provides an effective strategy for fabricating enhanced flame retardants to improve the performance of polymers. [ABSTRACT FROM AUTHOR]

Oral tablets containing solubilized drug in the presence of appropriate excipients may give us an immediate release of the drug. Phospholipid solid dispersion (PSD) is a branch of solid dispersion in which phospholipid acts as a hydrophilic polymer in the presence of a suitable adsorbent to enhance the solubility of poorly soluble drugs. The anti-hyperlipidemic drug Atorvastatin (ATR) is an example of such drug, as it belongs to the class II group according to the biopharmaceutical classification system (BCS) with low bioavailability due to its low solubility. Phosphatidylcholine in combination with magnesium aluminum silicate as an adsorbent in a ratio of ATR: PC: MAS 1:3:4 was used to prepare ATR PSD by the solvent evaporation method, the product showed acceptable physical properties and utilized for the preparation of immediate-release tablets (IRTs) of ATR. Ten formulas of ATR-IRTs were prepared by direct compression method using different types and concentrations of diluents (Avicel®PH102, Avicel®PH101, and starch) and superdisintegrants (crospovidone, croscarmellose sodium, and sodium starch glycolate) and evaluated for their drug content, weight variation, hardness, friability, in vitro disintegration time and dissolution profile. The tablets formula (T10) that were prepared with ATR-PSD and Avicel®PH102 as a diluent and Croscarmellose Sodium (CCS) 5% w/w as super disintegrant show the shortest disintegration time (DT) (38 ±1 sec.) and best drug release (91% within 15 min) in 0.05M phosphate buffer (pH 6.8). [ABSTRACT FROM AUTHOR]

Thermal barrier coatings (TBCs) are susceptible to corrosion by molten calcium-magnesium-aluminium-silicate (CMAS) during high temperature service. The microstructural evolution and thermal cycling lives of double-layer La2Ce2O7 (LC)/yttria partially stabilised zirconia (YSZ) and single-layer YSZ coatings were comparatively studied by a burner rig corrosion test. The results suggest that the thermal cycling life of double-layer LC/YSZ coating is approximately 80% longer than that of single-layer YSZ counterpart. The CMAS penetrated into the whole YSZ coating, which remarkably accelerated the spallation failure of the coating. However, due to the superior CMAS resistance of the LC layer, the failure of the double-layer LC/YSZ coating was mainly caused by the sintering of the LC layer, which resulted in a large in-plane stress and initiation of cracks. These cracks propagated, branched and deflected along the LC/YSZ interface, ultimately leading to the spallation of the LC layer. [ABSTRACT FROM AUTHOR]

Hard ceramic coatings were successfully prepared on the surface of ZM5 magnesium alloy by micro-arc oxidation (MAO) technology in silicate and aluminate electrolytes, respectively. The optimization of hard ceramic coatings prepared in these electrolyte systems was investigated through an orthogonal experimental design. The microstructure, elemental composition, phase composition, and tribological properties of the coatings were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and tribological testing equipment. The results show that the growth of the hard ceramic coatings is significantly influenced by the different electrolyte systems. Coatings prepared from both systems have shown good wear resistance, with the aluminate electrolyte system being superior to the silicate system in performance. The optimized formulation for the silicate electrolyte solution has been determined to be sodium silicate at 8 g/L, sodium dihydrogen phosphate at 0.2 g/L, sodium tetraborate at 2 g/L, and potassium hydroxide at 1 g/L. The optimized formulation for the aluminate electrolyte solution consists of sodium aluminate at 5 g/L, sodium fluoride at 3 g/L, sodium citrate at 3 g/L, and sodium hydroxide at 0.5 g/L. [ABSTRACT FROM AUTHOR]

The objective of this study was to demonstrate the potential utilization of fly ash (FA), wood ash (WA), and metakaolin (MK) in developing new alkali-activated materials (AAMs) for the removal of cadmium ions from waste water. The synthesis of AAMs involved the dissolution of solid precursors, FA, WA, and MK, by a liquid activator (Na2SiO3 and NaOH). In concentrated solutions of the activator, the formation of an aluminosilicate gel structure occurred. DRIFT spectroscopy of the AAMs indicated main vibration bands between 1036 cm−1 and 996 cm−1, corresponding to Si-O-Si/Si-O-Al bands. Shifting vibration bands were seen at 1028 cm−1 to 1021 cm−1, indicating that the Si-O-Si/Si-O-Al bond is elongating, and the bond angle is decreasing. Based on the X-ray diffraction results, alkali-activated samples consist of an amorphous phase and residual mineral phases. The characteristic "hump" of an amorphous phase in the range from 20 to 40° 2θ was observed in FA and in all AWAFA samples. By the XRD patterns of the AAMs obtained by the activation of a solid three-component system, a new crystalline phase, gehlenite, was identified. The efficiency of AAMs in removing cadmium ions from aqueous solutions was tested under various conditions. The highest values of adsorption capacity, 64.76 mg/g (AWAFA6), 67.02 mg/g (AWAFAMK6), and 72.84 mg/g mg/g (AWAMK6), were obtained for materials activated with a 6 M NaOH solution in the alkali activator. The Langmuir adsorption isotherm and pseudo-second kinetic order provided the best fit for all investigated AAMs. [ABSTRACT FROM AUTHOR]

To study the influence of the nucleation mechanism in lithium aluminosilicate glass, a composition similar to commercially produced glass was used. The glass-ceramics was obtained as a result of two-stage heat treatment, differing in the nucleation temperature and coinciding in the temperature and time of crystal growth. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) were used to study the formed nanocrystals. It was shown that the change of nucleation temperature in the glass transition interval T g ±15 °C significantly affects the coefficient of thermal expansion, which is due to the formation of a different number of nanocrystals of the general composition Li x Al x Si 1- x O 2 with x = 0.33 with the size less than 50 nm. [ABSTRACT FROM AUTHOR]

2,4‐dimethylfuran has a rare disubstitution pattern in the five‐membered heterocyclic furan ring that is highly interesting chemically but challenging to access synthetically. We present a heterogeneously catalysed route to synthesise 2,4‐dimethylfuran from commonly available 2,5‐dimethylfuran using a zeolite packed‐bed flow reactor. As supported by DFT calculations, the reaction occurs inside the zeolite channels, where the acid sites catalyse proton transfer followed by migration of a methyl group. The zeotype Ga‐silicate (MFI type) appears superior to an aluminium‐containing ZSM‐5 by demonstrating higher selectivities and slower catalyst deactivation. This work provides new opportunities for the continuous valorisation of bio‐feedstock molecules in the perspective of the emerging biorefinery era. [ABSTRACT FROM AUTHOR]

The dependence of the ζ-surface potential of synthetic aluminosilicates with a montmorillonite structure of systematically varying Na2x(Al2(1 –x),Mg2x)Si4O10(OH)2·nH2O composition, where 0.1 ≤ x ≤ 0.9, on the chemical composition of the samples and the pH of the environment is studied. The influence of the degree of isomorphic substitution of magnesium atoms by aluminum on the nature of the change of the ζ‑potential is shown. An increase in the degree of isomorphic substitution and an increase in the pH of the medium is accompanied by an increase in the negative charge of the sample surface. The results obtained make it possible to select the optimal compositions of aluminosilicate sorbents for the extraction of differently charged ions from aqueous solutions with different pH values and for use as carriers of drugs. [ABSTRACT FROM AUTHOR]

Aluminosilicates, such as montmorillonite, kaolinite, halloysite, and diatomite, have a uniform bidimensional structure, a high surface-to-volume ratio, inherent stiffness, a dual charge distribution, chemical inertness, biocompatibility, abundant active groups on the surface, such as silanol (Si-OH) and/or aluminol (Al-OH) groups. These compounds are on the list of U.S. Food and Drug Administration-approved active compounds and excipients and are used for various medicinal products, such as wound healing agents, antidiarrheals, and cosmetics. This review summarizes the wound healing mechanisms related to the material characteristics and the chemical components. Numerous wound dressings with different active components and multiple forms have been studied. Then, medicinal mineral resources for use in hemostatic materials can be developed. [ABSTRACT FROM AUTHOR]

To achieve better process control of silicon (Si) alloy production using aluminum as a reductant of calcium silicate (CaO-SiO2) slag, it is necessary to understand the reaction phenomena concerning the behavior of formed phases at the metal-slag interface during conversion. The interfacial interaction behavior of non-agitated melt was investigated using the sessile drop method for varying time and temperature, followed by EPMA phase analysis at the vicinity of the metal–slag interface. The most remarkable features of the reaction were the accumulation of solid calcium aluminate product layers at the Al alloy–slag interface and spontaneous emulsion of Si-alloy droplets in the slag phase. The reduction is strictly limited at 1550 °C due to the slow transfer of calcium aluminates away from the metal-slag interface into the partially liquid bulk slag. Reduction was significantly improved at 1600–1650 °C despite an interfacial layer being present, where the conversion rate is most intense in the first minutes of the liquid–liquid contact. A high mass transfer rate across the interface was shown related to the apparent interfacial tension depression of the wetting droplet along with a significant perturbed interface and emulsion due to Kelvin–Helmholtz instability driven by built-up interfacial charge at the interface. The increased reaction rate observed from 1550 °C to 1600–1650 °C for the non-agitated melt was attributed to the advantageous physical properties of the slag phase, which can be further regulated by the stoichiometry of metal–slag interactions and the composition of the slag. [ABSTRACT FROM AUTHOR]

Soil is the basic material for the manufacture of compressed earth bricks, which is worked without any type of stabilization to obtain the minimum physical and mechanical properties required according to Peruvian standard E.070. The objective of this research is to evaluate the physical and mechanical characteristics of compressed earth bricks stabilized with different dosages of 5, 8, 12, 12, 15 and 18% of cement in dry weight of soil. The tests performed were: absorption, compressive strength, flexural strength per unit of masonry, compressive strength in piles, diagonal compressive strength of walls and the X-ray diffraction test. The results obtained show that with 18% of cement the optimum resistance is obtained, in terms of compressive strength increased by 53.95%, flexural strength by 43%, pile compressive strength by 36.6%, and wall diagonal compressive strength by 41.24%, respectively. The X-ray diffraction test applied to the optimum stabilized compressed earth brick sample shows that its composition is dominated by certain components such as 32.4% calcium silicate, 23.8% aluminum silicate, 17.4% hydrated calcium, 14.2% illite, 6.86% calcium oxide, 3.34% quartz, 1.2% kaolinite and 0.8% goethite. It is concluded that cementstabilized compressed earth bricks (LTCEC) are a sustainable construction alternative that improves the mechanical properties of earth bricks. [ABSTRACT FROM AUTHOR]

In order to find safe and low-cost salt-activated materials to prepare soil polymers, light burned metakaolin was obtained after firing Guangxi kaolin at 850 °C for 4 h and added with different amounts of condensed aluminum phosphate, lithium phosphate and lithium silicate (3%, 4% and 5% of the metakaolin mass, respectively) as the additives to prepare soil polymers. Subsequently, the mixtures of metakaolin with lithium silicate, lithium phosphate or condensed aluminum phosphate were added to the corundum castable system, respectively, and the performance of the castables was compared with that of calcium aluminate bonded corundum castables. The effects of the additives on the solidification time, phase composition and microstructure of the obtained soil polymers as well as the soil polymers on the properties of the castables were explored. The results show that: (1) the solidification time of the soil polymers increases from 2 h to 5 h with the increasing additive addition, and the preferred addition is 4%; (2) at 20 °C, condensed aluminum phosphate reacts with metakaolin to form gelling SiP2O7, while lithium silicate and lithium phosphate react with metakaolin to form LiAISiO4, forming a layered structure or a gelling film attached to the surface of metakaolin, thus resulting in a gelation effect of soil polymers; (3) at 1 100 °C, soil polymers gradually form mullite, and layered metakaolin becomes thinner and cross connected; at 1 600 °C, the mull-itization of soil polymers is complete, forming needle and rod structures that cross connect with each other, and a small amount of liquid is generated, densifying the sample; (4) replacing calcium aluminate cement with soil polymers in the same proportion as the binder, the castable has a certain gap in performance compared to the calcium aluminate cement bonded castable. [ABSTRACT FROM AUTHOR]