Needle-like Morphology Research Articles

Synthesize and characterization of a novel sol–gel-driven Bi2O3 semiconductor: complete degradation and fast photocatalytic activity for paracetamol

Abstract The pollutants are getting released fluently as a waste from the pharmaceutical pollutants leading to the decrease in quality of water. The widespread occurrence of pharmaceutical pollutants poses a serious threat to the environment and human health. Besides, today carbon dioxide emissions and other forms of pollution appear to be a critical global issue. In this study, Bi2O3 catalyst has been prepared via co-precipitation (CP) and a facile sol–gel (SG) methods used as photocatalyst for the degradation of paracetamol (PAR) under different light sources. The preparation method has significant effect on the optical and structural properties of the catalysts. The tetragonal phase of Bi2O3, the presence of more surface OH groups and lower band gap energy remarkably improved the sun-light-driven photoactivity of PAR. The photocatalysts have been characterized by some structural and morphological analysis techniques and optical analysis techniques. In addition, zeta potential (ZP) measurements were performed to explain the impact of the initial pH of solution on photocatalytic degradation. Identification of PAR and the reaction intermediates was determined using Liquid Chromatography-Mass/Mass Spectrometry (LC-MS/MS) technique. Higher photocatalytic activity was obtained with the Bi2O3-SG (1:2) catalyst at pH 5 compared to the activity of Bi2O3-CP. Moreover, Bi2O3-SG (1:2) achieved the highest photocatalytic activity at pH 3. The photocatalytic activity was enhanced, and the time required for 100% degradation of PAR was reduced from 60 min to 30 min and 15 min under UVB irradiation and directly sun light irradiation, respectively. The highest reaction rate (0.086 (min−1)) were obtained in 15 min with the Bi2O3-SG (1:2) catalyst. The results showed TOC removal could be achieved in 60 min 99.19 and 88.97% for Bi2O3-SG and Bi2O3-CP, respectively. In general, sol–gel-driven Bi2O3 as a flower and needle-like morphology, can reveal excellent opportunities in the photocatalytic technology. Graphical Abstract

Mechanochemical Activation of Nickel Oxide Enabling Binder-Free Anodes for Alkaline Water Electrolysis

In recent decades, the imperative for clean energy generation has grown significantly. Water electrolysis stands out as a sustainable method for hydrogen production due to its zero carbon emissions. However, high energy requirements and costs hinder its widespread adoption for large-scale applications [1]. Non-noble metal-based materials have emerged as cost-effective and efficient anodes for the oxygen evolution reaction (OER). However, the stability and performance of these materials heavily rely on the integration of ionomers or binders into the electrode coatings. For example, Nafion, renowned for its high ionic conductivity and ability to stabilize coating structures [2], has been a preferred choice [3]. Yet, their high cost and impending regulations concerning per- and polyfluoro alkyl substances (PFAS) by European agencies necessitate the exploration of alternative approaches. Here, we propose a solution involving binder-free anode coatings, achieved through mechano-chemical activation via planetary ball milling of commercially available catalyst materials. This innovative method offers a promising avenue for developing environmentally sustainable anodes with effective performance, circumventing the limitations associated with conventional binder materials.In this study, nickel oxide (NiO, Merck group) was processed without binders through a modification of the powder material via planetary ball milling where parameters as bead size, rotation speed, and process time were varied. The initial visual contrast transformation from the green hue of the NiO feed to a dark grey or black shade appearance after ball milling which might indicate the presence of Ni2O3. Additionally, certain samples exhibited a needle-like morphology, with particle enlargement occurring selectively in instances involving larger beads during the milling process. These samples were discarded due to missing processability. Powder characterizations were conducted on both the as-purchased NiO feed (as reference) and the ball milled samples. Transmission electron microscopy (TEM) analysis confirmed reduced primary particle size across all ball milled samples as shown in the inset of Figure 1a-b. Energy dispersive X-ray (EDX) analysis indicated a decrease in the Ni metal content with a simultaneous increase in the oxygen content, while – in line with our expectations [4] – the reduced crystallinity of all NiO phases after ball milling was confirmed by X-ray diffraction (XRD) analysis. With regard to the surface species, Fourier-transform infrared (FTIR) spectroscopy evidenced a significant increase of hydroxide (OH) in the ball milled samples. At the same time X-ray photoelectron spectroscopy (XPS) data revealed an increase in the Ni3+ content, followed by a decrease in Ni2+ as analyzed from the Ni 2p spectrum. Combining both findings, we expect an improved anode performance due to the formation of Ni(OH)2 or NiOOH species [5]. Preliminary dispersion experiments were realized in different probe liquids [6] and subsequently the Hansen solubility parameters (HSP) were determined to achieve high-quality dispersions efficiently [7]. Because of the large particle size, all dispersions based on commercial NiO sedimented quickly, whereas the ball milled samples with significantly reduced primary particle size were stable in liquids like ethanol and isopropanol.This finding was quantified by transmittograms, where the sedimentation time, radial position and transmission are plotted together as shown in Figure 1a-b. Due to the inadequate dispersion stability of commercial NiO and thus missing processability, no electrodes were realized with this material. Finally, the ball milled samples were spray-coated onto Ni plate substrates without using binders. Scanning electron microscopy (SEM) images displayed diverse distributions of catalyst particles implying different coating structures and a range of morphologies. Electrochemical measurements at 100 mA cm-2 evidenced an improved activity of ~100 mV for the electrodes that were fabricated from the ball milled samples (Sample 1: 400 rpm, 4 h, Sample 2: 250 rpm, 2 h, constant bead size of 0.3 mm) during oxygen evolution compared to the bare Ni plate substrate as shown in Figure 1c. Within 2 h of testing, no delamination of the material was monitored evidencing its chemical and mechanical stability as a binder-free catalyst layer.In conclusion, this study presents a promising approach to achieve binder-free anodes enabled by mechanochemical activation. The versatility of this method offers opportunities to optimize non-noble metal-based materials for enhanced OER performance, thereby advancing the prospects of sustainable energy generation.

Eco-friendly synthesis of ZnO nanoparticles fabricated using Fioria vitifolia L. and their Biomedical Potentials

The present study aimed to environmentally friendly synthesis of ZnO NPs using Fioria vitifolia leaf extracts which provides a sustainable and green approach for production of NPs. The produced ZnO NPs were evaluated using various spectrum approaches (UV-vis, FTIR XRD, TEM and EDAX). The synthesized ZnO NPs was confirmed by UV-Visible spectroscopy exhibited a peak at 370 nm. SEM imaging revealed a flash-like and needle-like bottom morphology. Fourier-transform infrared spectroscopy (FTIR) analysis detected vibrations corresponding to alcohols, halides, and aromatics functional groups. TEM showed spherical-shaped NPs with an average diameter of 11 nm. XRD analysis exhibited distinct peaks at 2θ values of 31.7°, 34.3°, 36.2°, 47.4°, 56.6°, 62.8°, 66.4°, 67.9°, 69.1°, and 76.8°, corresponding to the crystallographic planes (100), (002), (101), (102), (110), (103), (200), (112), (201), (004), and (202) planes respectively. The antibacterial activity demonstrated significant zones of inhibition against E. coli (17±0.6 mm) and S. aureus (23.7±0.5 mm), and inhibition of biofilm formation in S. aureus and C. albicans. Additionally, S. mutans exhibited the highest sensitivity to the minimum inhibitory concentration (MIC) of ZnO NPs, with complete inhibition occurring at 7.5 μg/mL. Furthermore, antioxidant DPPH assays exhibited IC50 values of 42 μg/mL. Additionally, the anti-inflammatory properties of ZnO NPs of F. vitifolia were evaluated in-vitro using models utilizing the human red blood cells (HRBC) membrane stabilization method (MSM), and it was shown to have an MSM of 83.87% at 250 μg/mL. Furthermore, ZnO NPs exhibited anticancer activity against the MDA-MB-231 breast cancer cell line with an IC50 value of 35.50 μg/mL. Toxicological evaluation of FV-ZnO nanoparticles in zebrafish (Danio rerio) embryos indicated low toxicity at maximum concentration. These is first findings suggest that ZnO NPs synthesized from F. vitifolia leaf extracts possess significant antibacterial, antioxidant, anti-inflammatory, and anticancer properties. Additionally, their low toxicity in zebrafish embryos makes them suitable for further development in antimicrobial therapies with minimal side effects, offering a sustainable, biocompatible solution to tackle multidrug-resistant microbial infections.

Structural, optical, and surface analysis of Dy³⁺ doped Ba₂Mg(BO₃)₂ phosphor for w-LED applications

The present study reports on the phase formation, spectral, surface, and luminescence properties of the yellowish-white emitting Ba2Mg(BO3)2:Dy3+ phosphors synthesized by the solid-state reaction method. The XRD and Rietveld refinement results confirm the trigonal phase of BaMg(BO3)2:Dy3+ with space group R-3m. The scanning electron microscopy image shows the needle-like morphology of the synthesized particles. The band structure of the Ba2Mg(BO3)2 host has been investigated in the framework of the density functional theory (DFT) by evaluating the band structure and density of states (DOS). Under 350 nm excitation, all the phosphors emit yellowish-white light with CIE color coordinates of (x = 0.39, y = 0.39). The optimum PL concentration of Dy3+ doped Ba2Mg(BO3)2 host was obtained to be 2.5 mol % with a critical distance of 21 Å and a CCT value of 4240 K. The X-ray photoelectron study reveals the presence of all the elements on the surface of the phosphor. The result shows that Ba2Mg (BO3)2:Dy3+ phosphors can be considered as a yellowish-white light emitter in w-LEDs.

Strong and Environmental-Friendly Adhesive Glass Based on Chitin Nanoparticles

Chitin is a biopolymer that can be used as a candidate material for a strong and environmentally friendly glass adhesive. In the form of nanoparticles with needle-like morphology and attractive functional groups in the form of amide and hydroxyl, Chitin Nanoparticle (ChNP) shows a strong Van der Walls adhesive force against glass. In the study, ChNP was successfully isolated from crab shells from the sea of Lombok. The isolated ChNP has a characteristic size around 351 nm with -chitin conformation and needle-shaped morphology. Based on the results of shear strength testing, 0.42 mg of ChNP can withstand a load of 21 kg and the addition of Gum Arabic (GA) and Hen Egg White lysozyme (HEWL) in a ratio of 1: 1 to ChNP succeeded in increasing adhesion by 72%.

Comprehensive Advanced Physicochemical Characterization and In Vitro Human Cell Culture Assessment of BMS-202: A Novel Inhibitor of Programmed Cell Death Ligand.

Background/Objectives: BMS-202, is a potent small molecule with demonstrated antitumor activity. The study aimed to comprehensively characterize the physical and chemical properties of BMS-202 and evaluate its suitability for topical formulation, focusing on uniformity, stability and safety profiles. Methods: A range of analytical techniques were employed to characterize BMS-202. Scanning Electron Microscopy (SEM) was used to assess morphology, Differential Scanning Calorimetry (DSC) provided insights of thermal behavior, and Hot-Stage Microscopy (HSM) corroborated these thermal behaviors. Molecular fingerprinting was conducted using Raman spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy, with chemical uniformity of the batch further validated by mapping through FTIR and Raman microscopies. The residual water content was measured using Karl Fisher Coulometric titration, and vapor sorption isotherms examined moisture uptake across varying relative humidity levels. In vitro safety assessments involved testing with skin epithelial cell lines, such as HaCaT and NHEK, and Transepithelial Electrical Resistance (TEER) to evaluate barrier integrity. Results: SEM revealed a distinctive needle-like morphology, while DSC indicated a sharp melting point at 110.90 ± 0.54 ℃ with a high enthalpy of 84.41 ± 0.38 J/g. HSM confirmed the crystalline-to-amorphous transition at the melting point. Raman and FTIR spectroscopy, alongside chemical imaging, confirmed chemical uniformity as well as validated the batch consistency. A residual water content of 2.76 ± 1.37 % (w/w) and minimal moisture uptake across relative humidity levels demonstrated its low hygroscopicity and suitability for topical formulations. Cytotoxicity testing showed dose-dependent reduction in skin epithelial cell viability at high concentrations (100 µM and 500 µM), with lower doses (0.1 µM to 10 µM) demonstrating acceptable safety. TEER studies indicated that BMS-202 does not disrupt the HaCaT cell barrier function. Conclusions: The findings from this study establish that BMS-202 has promising physicochemical and in vitro characteristics at therapeutic concentrations for topical applications, providing a foundation for future formulation development focused on skin-related cancers or localized immune modulation.

Thermal conductivity of binary Al alloys with different alloying elements

This work investigates the physical properties of several binary Al-Si/Ni/Fe/Cu/Mg alloys with varying alloying element contents and microstructures. The findings indicate that as the content of alloying elements increases, the number of secondary phases in binary Al alloys rises, and these phases become coarser. In hypereutectic compositions, primary phases in Al-Ni and Al-Fe alloys take on a needle-like morphology with high aspect ratios, forming a dendritic network. Regarding properties, in the hypoeutectic region, both thermal conductivity and electrical conductivity of binary alloys initially decrease sharply, followed by a more gradual decline with the addition of alloying elements. This trend occurs because thermal conductivity is mainly influenced by supersaturated solid solutions. In hypereutectic Al-Ni and Al-Fe alloys, the presence of large, needle-like primary phases significantly hinder the heat transfer, resulting in a more apparent reduction in both thermal conductivity and electrical conductivity. Among the five binary alloys, Al-Ni and Al-Fe alloys, which have lower solute concentrations of alloying elements in the Al matrix, exhibit the highest thermal and electrical conductivity. Furthermore, with increasing alloying element contents, the phonon thermal conductivity of Al-Si alloy increases more markedly compared to other alloys. The study will offer a fundamental understanding for the development of advanced alloys.

Radiative recombination model for BiSeI microcrystals: unveiling deep defects through photoluminescence

Abstract Pnictogen chalcohalides are semiconductors that have emerged as promising materials for energy conversion due to their exceptional optoelectronic properties. Their electronic configuration (ns2), particularly for Bi- and Sb-based compounds, can be a key factor in efficient carrier transport and defect tolerance, similarly, to Pb-perovskites. In the present study, the Bi-containing chalcohalide, bismuth selenoiodide (BiSeI) was synthesized via isothermal heat treatment of binary precursors in evacuated quartz ampoules. The synthesized BiSeI microcrystals exhibited a characteristic needle-like morphology and a near-stoichiometric composition. Both indirect and direct band gap energies of BiSeI were determined by ultraviolet–visible–near-infrared diffuse reflectance spectroscopy, with room temperature values of 1.17 eV and 1.29 eV, respectively. This study presents the first experimental investigation of the photoluminescence properties of BiSeI microcrystals resulting in a recombination model involving multiple defect states. This work provides valuable insights into the defect structure and recombination mechanisms within BiSeI, paving the way for further exploration of its potential in optoelectronic devices.

Deconstructing 3D growth rates from transmission microscopy images of facetted crystals as captured in situ within supersaturated aqueous solutions.

Here, a morphologically based approach is used for the in situ characterization of 3D growth rates of facetted crystals from the solution phase. Crystal images of single crystals of the β-form of l-glutamic acid are captured in situ during their growth at a relative supersaturation of 1.05 using transmission optical microscopy. The crystal growth rates estimated for both the {101} capping and {021} prismatic faces through image processing are consistent with those determined using reflection light mode [Jiang, Ma, Hazlehurst, Ilett, Jackson, Hogg & Roberts (2024 ▸). Cryst. Growth Des. 24, 3277-3288]. The growth rate in the {010} face is, for the first time, estimated from the shadow widths of the {021} prismatic faces and found to be typically about half that of the {021} prismatic faces. Analysis of the 3D shape during growth reveals that the initial needle-like crystal morphology develops during the growth process to become more tabular, associated with the Zingg factor evolving from 2.9 to 1.7 (>1). The change in relative solution supersaturation during the growth process is estimated from calculations of the crystal volume, offering an alternative approach to determine this dynamically from visual observations.

Solidified characteristic and enhanced properties of Al0.5MnFeNiCu0.5/Al–Ni functionally gradient coating fabricated by laser cladding on AZ91HP

To ensure the high entropy effect of the coating, it is necessary to control the dilution of Mg during laser cladding process. Therefore, Al0.5MnFeNiCu0.5/Al–Ni functionally gradient coating was proposed in this work. More remarkable, the design of Al–Ni transition layer effectively prevented the dilution of Mg into Al0.5MnFeNiCu0.5 layer, and relieved physical and chemical differences between Al0.5MnFeNiCu0.5 layer and Mg alloy. Al0.5MnFeNiCu0.5 layer exhibited flower-like grain consisted of BCC phase. Al–Ni remelting layer crystallized as the fine snowflake-like grain. Al–Ni layer presented coarse needle-like grain morphology. Microhardness of Al0.5MnFeNiCu0.5 layer was about 8.2 times more than that of the substrate. Specifically, compared with Mg alloy and Al–Ni layer, the wear volume of Al0.5MnFeNiCu0.5 layer were decreased by 87.83% and 50.38%, respectively. The results of Polarization curve, Nyquist curve and Bode plot indicated that Al0.5MnFeNiCu0.5 layer displayed better corrosion resistance than Al–Ni layer and Mg alloy.

Acid precipitation-hydrothermal synthesis of needle-like hydroxyapatite for protein adsorption from waste phosphogypsum

ABSTRACT In order to promote the high-value utilization of waste phosphogypsum (PG), hydroxyapatite was directly synthesized from PG by acid precipitation-hydrothermal method (PGHAP), which was used for the adsorption of bovine serum albumin (BSA) and lysozyme (LYS). The synthesized PGHAP was characterized by XRD, SEM, FTIR and BET, and the effects of various factors on protein adsorption capacity were studied. The results showed that PGHAP exhibits a clear needle-like morphology, high crystallinity, and an average size of about 200 nm. The pH had the greatest effect on the adsorption of protein, and the highest adsorption capacity was obtained at pH 4.0. In addition, the adsorption mechanism of protein on PGHAP was explored by adsorption kinetics and adsorption isotherm. The adsorption of protein on PGHAP conforms to the Intra-particle diffusion model kinetic model, the maximum adsorption capacity of protein on PGHAP can reach 31 mg/g, which is comparable to other adsorbents in this field. In addition, the adsorption behaviour of PGHAP on protein is more appropriately described by Langmuir isotherm model, which indicates that the binding site with uniform energy on the surface of PGHAP realizes the monolayer adsorption of protein. The main adsorption mechanisms are ion exchange, co-precipitation, complexation reaction and so on. Therefore, the needle-like PGHAP synthesized from waste PG is a protein adsorbent with industrial application potential.

NiCo layered double hydroxides/carbon dots composites with S-doing for high-performance asymmetric supercapacitors

The pursuit of high-performance electrode materials for supercapacitors has led to the exploration of transition metal layered double hydroxides (LDH), which boast an impressive theoretical specific capacitance. However, their intrinsic limitations, such as poor electronic conductivity and slow diffusion kinetics, have posed significant challenges for their practical implementation. In this work, a NiCo LDH/carbon dots (CDs) composite with S-doping has been meticulously designed to overcome the aforementioned limitations through a synergistic combination of heteroatom doping and carbon incorporation. Utilizing a one-pot hydrothermal method, the composite electrode for the application of asymmetric supercapacitors have been in-situ growth on Ni foam substrate, which not only serves as a robust support but also contributes to the formation of NiCo LDH by providing a uniform Ni source, thereby ensuring strong adhesion and structural integrity. The morphology and microstructures of composites could be finely modulated by adjusting CDs amount. With moderate CDs contents, the optimum electrode S-LDH/CDs-2 exhibits distinctive 3D needle-like spherical morphology, coupled with the ample space for ion diffusion. Consequently, the electrode demonstrates outstanding electrochemical performance, featuring a high areal capacitance of 5157 mF cm−2 at a current density of 2 mA cm−2. Additionally, it exhibits noteworthy rate performance and maintains excellent cycling stability. Integrating the innovative electrode into asymmetric supercapacitors configuration, superior energy density (0.24–0.45 mWh cm−2) and power density (4–20 mW cm−2) as well as good stability have been achieved for the S-LDH/CDs-2//AC device. These results indicate that S-doped NiCo LDH/CDs composite electrode has the desirable potential to be a candidate for energy storage devices.

Effect of Anisotropy on Lithium Dendrite Growth

Lithium dendrite formation is one of the leading causes of performance degradation and safety hazards in lithium batteries. Understanding dendrite evolution and its morphology during cycling can provide the critical insight into improving battery performance and safety. Recent experimental studies with cryo-electron microscopy have revealed anisotropic morphologies of lithium metal during deposition. Lithium, being a crystalline material, exhibits different surface energies and reaction rates depending on the crystal surfaces. In this study, we apply a quantitative electrochemical phase-field model to study the impact of thermodynamic and kinetic anisotropy on lithium morphology during battery cycling. We examine scenarios involving the alignment or misalignment of lithium crystals with the applied current. We observe that due to the rapid deposition rates, lithium dendrites tend to grow along crystal directions with high kinetics, resulting in a needle-like morphology. Furthermore, we study the effect of anisotropy magnitude on morphology selection, as well as the interaction between neighboring dendrites during cycling and the effect of various factors, including the applied current and electrolyte properties. Overall, this study elucidates the relationship between lithium dendrite morphology and various factors, ultimately contributing to the development of improved batteries with enhanced performance and safety.

Synthesis of zincosilicates of dual morphology by hydrothermal method assisted by sonication

The obtaining of nanostructured zeotypes is of interest due to their large active surface area and porous structure, specifically zincosilicates stand for their photocatalytic properties. In this work, zincosilicates were synthesized by a strategic methodology that combined sonication and aging step, followed by hydrothermal treatment. The effect of sonication time on crystallinity, morphology, chemical composition and defects of synthesized zincosilicates were evaluated. The sonication time longer than 0.5 h favored the obtaining of crystalline zincosilicate. The increase in sonication time led to formation of nanostructured zincosilicates constituted by nanosheets and nanorods. Aggregates of needles tangled and faceted-sheets stacked formed particles of dual morphology bird nest-like and accordion-like shapes. The highest content of zinc was detected in needle-like morphologies. The nanostructured zincosilicates exhibited the higher amount of surface defects (ionized oxygen vacancies).

Influence of multiphase microstructure on the strength and ductility of Nb–Zr–Ti–V refractory high entropy alloys

In this investigation, we focused on the lightweight Nb–Zr–Ti–V alloys as representative model alloys to explore improving mechanical properties of refractory high entropy alloys (RHEAs) through phase engineering. The alloys were deliberately designed with different element concentrations and varied cooling rates after homogenization treatment, resulting in formation of multiple secondary phases. Microstructures of prepared alloys were reported, revealing the decomposition of the BCC matrix into dual-BCC phases with increasing V content. We attribute this phenomenon to the substantial atomic size misfit between V and Zr. Additionally, a metastable FCC phase and an intermetallic Laves phase emerged at intermediate temperatures in Nb0.75ZrTiV0.75, influenced by the nonequilibrium condition during cooling and the enthalpic effect. Compression tests were performed to access mechanical characteristics of different phases. The dual-BCC phases, featuring granular or multilayer morphology, enhanced ductility of the alloy by facilitating dislocation movement at BCC interfaces. In contrast, the FCC and Laves phases, characterized by a needle-like morphology, increased strength of the alloy owing to their intrinsic hardness. Based on the current discovery and understanding on secondary phases in the Nb–Zr–Ti–V alloys, our future objective is to obtain a modulated microstructure with an appropriate combination of different phases to optimize strength and ductility simultaneously.

On the microstructure and hardness evaluation of aluminum metal matrix composites reinforced with in situ (Fe-Al-Cr-Ni) intermetallic compounds

Abstract In this study, Aluminum metal matrix composites (AMMCs) were produced through stir casting technique, using in situ intermetallic compounds as reinforcement. The in situ synthesis of these reinforcement phases involved the addition of stainless-steel particles (type 316L) at various weight percentages of 5, 10, and 15 wt. %. The impact of varying the amount of stainless particles added on the hardness and microstructure of the resulting AMMCs was examined. X-ray diffraction patterns (XRD) and energy dispersive spectroscopy (EDS) analysis reveal the formation of two types of intermetallic compounds: iron aluminide intermetallic compounds in irregular plate and needle-like morphologies and another one with higher percentage of Cr in a hexagonal-plate like morphology. Microstructural characterization shows a reputable distribution of the newly formed intermetallic phases. The findings indicate that the hardness of the composites improves as the stainless particles content increases. Hardness of the AMMC fabricated by adding 15 wt.% stainless steel was tripled compared with that of pure aluminium.

Experimental study on the scaling law of the heat exchange tube surface in the process of low-temperature single-effect distillation of high-mineralized mine water

High-mineralized mine water, due to its characteristics such as high mineralization degree, will have scaling phenomena on the surface of the heat exchange tube during the desalination treatment process, resulting in a reduction in the water production efficiency of the equipment and affecting the normal operation. To reduce the cost of water production and improve the service life of distillation equipment, this paper independently designs and builds a low-temperature single-effect distillation high-mineralized mine water experimental system to study the influence of operating parameters (temperature, spray density, concentration ratio, and system pressure) on the scaling law on the surface of the heat exchange tube. The distribution and characteristics of scale deposits on the surface of the heat exchange tube are analyzed through the growth rate and microscopic morphology of the scale deposit. The results indicate that the scaling on the surface of the titanium plate is mainly in the needle-like and rod-like morphology of CaCO3 aragonite, and a small amount of CaSO4 and calcite are generated with the increase of temperature. It was found that within the range of spray density from 0.0509 kg/(m·s) to 0.0625 kg/(m·s), concentration ratio from 2.3 to 2.7, and system pressure at 36.3 kPa, it is beneficial to the evaporation heat transfer of the heat exchange tube and the reduction of scaling generation. At the same time, it is found that the scaling of the first row of heat exchange tubes is mainly within the range of circumferential angle from 0 to 100 degrees, and the scaling of the second row and the third row of heat exchange tubes is mainly within the range of circumferential angle from 110 to 170 degrees. The research results of this paper provide support for the design and operation of the low-temperature multi-effect treatment system for mine water in engineering, promote the process of zero discharge of high-mineralized mine water in Xinjiang, China, and improve the resource utilization rate of high-mineralized mine water.

Hydration and microstructure evolution of cement paste in low vacuum environments

Low vacuum is one of the most challenging service environments for cementitious materials, which would affect their hydration and microstructure, and thereby impair strength and durability. In this study, the hydration phases and microstructural evolution of pastes based on Portland cement (PC), sulphoaluminate cement (SAC), and tricalcium silicate (C3S, the clinker of PC) were investigated under low vacuum conditions. The results show that rapid mass loss could be observed at the initial stage of low vacuum treatment, which was mainly attributed to the dissipation of free water. After that, the mass loss rate was greatly slowed down and maintained at a relatively low level, which was primarily due to the loss of chemical bound water in hydration products. As a result, C3S samples, with the slowest early hydration procedure, exhibited the highest mass loss, which was followed by PC and SAC samples. The dissipation effect by low vacuum treatment resulted in the inhabitation of cement hydration, and correspondingly the contents of hydration products remained almost constant, or even decreased especially for ettringite (AFt). Moreover, the examination of the hydration product morphology demonstrates that under low vacuum conditions, the needle-like morphology of the hydration product C-S-H transferred gradually from divergence to convergence or underwent collapse, while the AFt crystals experienced degradation and then transformed into an amorphous state. This consequently led to the sample after low vacuum treatment exhibiting increased total volume of pores less than 100 nm and elevated percentage of pores with sizes from 50 nm to 100 nm. Overall, this research holds great scientific significance in guiding the engineering application of concrete in low vacuum environments.

Synthesis and Characterization of Vanadium Nitride/Carbon Nanocomposites.

The present work focuses on the synthesis of a vanadium nitride (VN)/carbon nanocomposite material via the thermal decomposition of vanadyl phthalocyanine (VOPC). The morphology and chemical structure of the synthesized compounds were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS). The successful syntheses of the VOPC and non-metalated phthalocyanine (H2PC) precursors were confirmed using FTIR and XRD. The VN particles present a needle-like morphology in the VN synthesized by the sol-gel method. The morphology of the VN/C composite material exhibited small clusters of VN particles. The XRD analysis of the thermally decomposed VOPC indicated a mixture of amorphous carbon and VN nanoparticles (VN(TD)) with a cubic structure in the space group FM-3M consistent with that of VN. The XPS results confirmed the presence of V(III)-N bonds in the resultant material, indicating the formation of a VN/C nanocomposite. The VN/C nanocomposite synthesized through thermal decomposition exhibited a high carbon content and a cluster-like distribution of VN particles. The VN/C nanocomposite was used as an anode material in LIBs, which delivered a specific capacity of 307 mAh g-1 after 100 cycles and an excellent Coulombic efficiency of 99.8 at the 100th cycle.

Simulation analysis of microstructure development of tricalcium silicate using the needle model of calcium silicate hydrate

This study proposes a two-scale model for tricalcium silicate (C3S) hydration to examine the microstructure of hydrated C3S paste. The needle-like morphology of a calcium silicate hydrate (C-S-H) layer, as observed in many studies, was constructed using this model based on the assumption of C-S-H needles. The boundary nucleation and growth pattern of the C-S-H needles were illustrated, and the impingement among C-S-H needles and particles was considered. The pore size distribution was calculated using the rolling sphere method for the hydrated particle system and C-S-H layer. The simulation results were compared with existing experimental data, revealing consistency for the C3S paste with different hydration times. The shape and growth parameters of the C-S-H needles were studied to model their microstructure. The microstructure constructed using this model was found to be more reasonable and could provide a more accurate description of the C-S-H morphology.