Particle Surface Research Articles

The removal of methylene blue from aqueous solutions by polyethylene microplastics: Modeling batch adsorption using random forest regression

In light of the extensive contamination of water sources by microplastics, their substantial specific surface area makes them favorable candidates as adsorbents for the simultaneous removal of coexisting contaminants in wastewater. In this regard, polyethylene microplastics were utilized to eliminate methylene blue dye from water. MB adsorption onto microplastics reached equilibrium in just 30 min at pH 7. The better fit of fractional power and Redlich-Peterson models on kinetic and equilibrium adsorption data, respectively, revealed that the MB removal process is a chemisorption in multilayer adsorption on the heterogeneous surface of the microplastics particles. The reusability of the microplastics adsorbent was confirmed based on the promising outcomes observed after five cycles. The results of the random forest regression exhibited an R2 of 97.55% for the correlation between the model-computed and measured amounts of MB reduction. The sensitivity analysis illustrated that the MB sorption process on microplastics is highly influenced by the initial MB concentration and adsorbent mass. These results show that although microplastics may pose potential risks to water environments, their adsorption potential can be utilized to simultaneously omit other pollutants from the aqueous solutions.

A synergistic dispersion strategy for high volume fraction slurry and high performance silicon nitride sintered components in digital light processing (DLP)-based vat photopolymerization

The digital light processing (DLP)-based vat photopolymerization enables the fabrication of intricate silicon nitride (Si3N4) components. However, challenges still persist in producing low-defect and high-performance ceramic parts at lower volume fractions. In this study, a new block copolymer was employed for the modification of Si3N4 powders. The rheological behavior, dispersant mechanism, curing properties, printing performance of green body, mechanical properties and Weibull modulus of the sintered sample were systematically investigated. The results indicated that the modifier characterized by the long molecular chains and CC double bonds adhered successfully to the surface of Si3N4 particles through hydrogen bonding, and the viscosity reduction effect of this modifier was ten times lower than that of the reported KH560 modifier. Besides, the synergistic dispersion effect achieved via the combination of the long chain modifier with a small molecular dispersant, facilitates the preparation of a 60 vol% (80.74 wt%) Si3N4 slurry. Subsequently, the tightly bonded interlayer of the green body and the complex Si3N4 sintered components with different volume fractions, high consistency and superb mechanical performance (the strength of 865.87 ± 54.35 MPa and the Weibull modulus of 18.49) were fabricated. These findings highlight the promising potential of the proposed modification approach for advancing the fabrication of high volume fraction and high-performance Si3N4 components.

A Bacterium-like Particle Vaccine Displaying Envelope Proteins of Canine Distemper Virus Can Induce Immune Responses in Mice and Dogs.

Canine distemper virus (CDV) can cause fatal infections in giant pandas. Vaccination is crucial to prevent CDV infection in giant pandas. In this study, two bacterium-like particle vaccines F3-GEM and H4-GEM displaying the trimeric F protein or tetrameric H protein of CDV were constructed based on the Gram-positive enhanced-matrix protein anchor (GEM-PA) surface display system. Electron microscopy and Western blot results revealed that the F or H protein was successfully anchored on the surface of GEM particles. Furthermore, one more bacterium-like particle vaccine F3 and H4-GEM was also designed, a mixture consisting of F3-GEM and H4-GEM at a ratio of 1:1. To evaluate the effect of the three vaccines, mice were immunized with F3-GEM, H4-GEM or F3 and H4-GEM. It was found that the level of IgG-specific antibodies and neutralizing antibodies in the F3 and H4-GEM group was higher than the other two groups. Additionally, F3 and H4-GEM also increased the secretion of Th1-related and Th2-related cytokines. Moreover, F3 and H4-GEM induce IgG and neutralizing antibodies' response in dogs. Conclusions: In summary, F3 and H4-GEM can provoke better immune responses to CDV in mice and dogs. The bacterium-like particle vaccine F3 and H4-GEM might be a potential vaccine candidate for giant pandas against CDV infection.

Enhancing interfacial synergies for the preparation of high mechanical strength and interconnected porosity of alumina extrudates through pre-wetting method

The forming of catalyst supports is a crucial step in the application of industrial catalysts. Alumina, a widely employed catalyst support, is often shaped using nitric acid as a peptizer to enhance mechanical strength. However, the use of large amounts of nitric acid typically results in a decrease in specific surface area and damage to the pore structure due to chemical corrosion. In this work, we present a more practical approach that is pre-filling the open pores of pseudo-boehmite powder with water instead of directly filling them with nitric acid solution. The binder with a small quantity of nitric acid plays a synergistic role in functioning as a glue on the particle surfaces. And through this method, high-strength (231 N cm−1) alumina support can be prepared more efficiently through extrusion. Besides, the pore structure of the extrudates was characterized by multi-scale methods, including nitrogen physical sorption and XRM (X-ray microscopy), which revealed abundant interconnected hierarchical pores deriving from the pre-wetting shaping process. This proposed approach enables the attainment of high mechanical strength and interconnected porosity for alumina extrudates with less use of acid, which holds a significant practical application value.

In English

Currently, textile and food industries produce a significant volume of sewages containing azo dyes and other organic pollutants. These effluents are serious environmental threats, so new methods for their treatment and the degradation of azo dyes are attracting much attention. Composite materials based on TiO2 modified by noble metals and nanoceria show high activity in the photodegradation of organic contaminates and are proposed for hydrogen synthesis as well. To optimize the treatment of contaminants, different processes can combine including the strategies of adsorption, photoluminescence, photocatalysis, etc. The synthesized TiO2-based nanomaterials (sols, powders) will be exploited for bioremediation due to their small size and surface plasmon resonance from noble metals. Binary nanocomposites based on TiO2 were obtained by the chemical co-precipitation method from solutions of titanium tetraisopropoxide (TTIP) and inorganic salts of cerium, silver, and palladium. It has been stated that TiO2 is represented by anatase with primary particle size (CSR) from 8.5 to 16.8 nm, depending on the nature and concentration of the dopant. It is shown that Ag is reduced on the surface of anatase particles and blocks their growth, while Pd and Ce penetrate the titanium dioxide matrix in the form of small clusters with the deformation of the anatase crystal lattice. Nanocomposite particles formed loose and fragile aggregates, which spontaneously dispersed in solutions of dyes with the formation of colloid-stable sols, required the use of a centrifugal field for their sedimentation. Nanoparticles of TiO2&Pd were electronegative and others were electropositive according to the values 4.1÷9.6 of ZPC (zero point of charge). It was shown that the particles of all composites sorbed Methylene Blue (MB) without photocatalytic activity under the visible light to any dye. Moreover, anionic dyes such as Orange-G (Or-G) and Methyl Orange (MO) were excellently discolorated in the presence of TiO2&Pd system; cationic dyes of MB and Rhodamine B (RhB) discolorated too with the TiO2, TiO2&CeO2, and TiO2&Ag systems under UV light action. As such, photocatalysis tests showed that Orange-G’s and MO’s discoloration was higher for TiO2&Pd (2 wt. %) and TiO2 systems with the correlation coefficient R2 0.999.

Dual-modified LiNi0.8Co0.1Mn0.1O2 cathode materials with lithium conducting hybrid oligomer and single-walled carbon nanotube for improving electrochemical performance and thermal stability of lithium-ion batteries: A novel approach for high-power and high-safety applications

In this study, we investigated the synergetic effect of a novel lithium-ion conducting hybrid oligomer [N, N′-bismaleimide-4, 4′-diphenylmethane (BMI), lithiated trithiocyanuric acid (Li-TCA) and Jeffamine®-M1000 (JA®); Li-BTJ] coating layer on a nickel-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material wrapped with highly electron-conductive single-walled carbon nanotubes (SWCNTs) to enhance electrochemical performance and thermal stability for high-power and high-safety lithium-ion batteries (LIBs). Morphological analyses using scanning electron microscopy/energy dispersive spectroscopy and transmission electron microscopy showed that the NCM811 active material surface was uniformly coated with a hybrid oligomer to form NCM811@Li-BTJ, which was subsequently wrapped with SWCNTs (NCM@Li-BTJ/SWCNT composite cathode). CR2032 coin-type cells with optimized NCM811@1 wt% Li-BTJ/0.2 wt% SWCNT composite electrodes delivered a significantly enhanced capacity retention (CR) of 90.1 % relative to that of bare NCM811 electrodes (CR: 82.1 %) at 1C for 200 cycles from 2.8 to 4.3 V (vs. Li/Li+). Electrochemical impedance spectroscopy and cyclic voltammetry revealed that this superior cycling performance resulted from a lower charge transfer resistance (Rct: 96.2 vs. 324.3 Ω) and a lower polarization voltage (∆V: 0.243 vs. 0.411 V vs. Li/Li+). The in-situ micro-calorimetric results presented the total heat generation (Qt) values of the coin cells with the delithiated NCM811@Li-BTJ and NCM@Li-BTJ/SWCNT electrodes at 5C and 35 °C were substantially lower by ~9.3 % and ~ 14.6 %, respectively, compared to the bare NCM811 counterpart, indicating that the surface modifications on the NCM811 active materials could prevent the LIBs' thermal instability. Furthermore, X-ray photoelectron spectroscopy studies revealed that the Li-BTJ hybrid oligomer coating layer effectively suppressed the formation of residual Li side products such as Li2CO3 evidently on the surface of the NCM811 active material particles, thereby inhibiting undesirable side reactions. Post-mortem analyses of the dual-modified NCM811 electrode after cycling revealed that the microstructure and particle morphology of the NCM composite cathode material were extensively maintained through the synergistic effects of the Li-BTJ ion-conductive and SWCNTs electron-conductive agents.

Characteristics of Pickering emulsions stabilized by microgel particles of five different plant proteins and their application

Pickering emulsions stabilized by protein particles are of great interest for use in real food systems. This study was to investigate the properties of microgel particles prepared from different plant proteins, i.e., soybean protein isolate (SPI), pea protein isolate (PPI), mung bean protein isolate (MPI), chia seed protein isolate (CSPI), and chickpea protein isolate (CPI). MPI protein particles had most desirable Pickering emulsion forming ability. The particles of SPI and PPI had similar particle size (316.23 nm and 294.80 nm) and surface hydrophobicity (2238.40 and 2001.13) and emulsion forming ability, while the CSPI and CPI particle stabilized emulsions had the least desirable properties. The MPI and PPI particle stabilized Pickering emulsions produced better quality ice cream than the one produced by SPI particle-stabilized emulsions. These findings provide insight into the properties of Pickering emulsions stabilized by different plant protein particles and help expand their application in emulsions and ice cream.

PRODUCTION AND RESEARCH OF SORBENTS FROM FOOD PLANT WASTES FOR WATER PURIFICATION

The article describes the results of research on production of modified types of sorbents based on waste food plants and the possibility of drinking water purification from Ca2+ and Mg2+ ions. Sunflower and buckwheat wastes widely spread in the East Kazakhstan region were selected for production of modified sorbent. Structural features of sunflower and buckwheat shells were studied. It was found that samples of the initial form of buckwheat and sunflower, washed with distilled water, consist of very dense and small micropores. It was found that the surface of the sorbents particles is changed by washing with alcohol solution, with pores and hillocks appearing on the surface of sunflower husk particles. In acid-base-treated sorbents, an increase in the number of macropores and a change in the general morphological structure are observed. As a result of defining the sorption capacity of sorbents produced by acid-alkaline activation, it is on average 0.06 mg/g in iodine and 1.3 mg/g in methylene blue higher than that of medical activated carbon. The results of materials sorption capacity study produced from sunflower husk, sequentially treated with 8.2% hydrochloric acid solution and 16,5% sodium hydroxide solution, indicated effect respect to Ca2+ and Mg2+ ions showed a high purification effect of 98.7% and 95.8%, respectively. The above-mentioned modified sorbent is proposed as a sorption material in the production of filters for drinking water purification.

Additive manufacturing of WE43 and modified AZ91D magnesium alloys using the laser engineered net shaping process

Magnesium alloys WE43 and AZ91D offer weight savings for structural applications. WE43 contains rare-earth elements such as yttrium and neodymium, whereas AZ91D and the AZ class of alloys are lower-cost containing aluminium and zinc. This work uses a modified version of the latter, identified as AZ91D*, where calcium and yttrium have been added. Laser Engineered Net Shaping (LENS) equipment was used to investigate the 3D printing behaviour of gas-atomized WE43 and AZ91D* material. Process evaluations were first done using single track laser scans across wrought substrates of WE43 and AZ31. Process parameters were then developed that enabled deposition of build coupons with less than 1% porosity. These were used for microstructural and mechanical property assessments. The energy densities used were in the range of 40 – 60 J/mm² for AZ91D*, while for WE43 a value of 50 J/mm² was selected. A focus of the work was managing the tendency of magnesium materials to fume heavily during deposition, while achieving a deposit with close to nominal density, i.e. having a low incidence of voids or other micro- or macro-structural defects. The porosity of AZ91D* builds did not seem to correlate with increasing deposition energy density, however WE43 builds did, up to a practical limit imposed by generation of excessive fume. WE43 generated much less fume than AZ91D*. Analysis of the input powder materials indicate the presence of oxides on the particle surfaces. The WE43 powders had a noticeable shell of yttrium oxide. The microstructures of WE43 builds show the presence of arc-shaped structures that are likely the same yttrium oxides, partially, or fully ‘unfolded’. Tensile testing was conducted on WE43 build coupons to assess the effect of a T6 heat treatment. The effect on the ultimate tensile and yield strengths was negligible, however the % elongation at break almost doubled. Inspection of the fracture surfaces suggests this was due to a change in mechanism from fracture initiation at sites of lack-of-fusion/un-melted particles, to a more ductile micro-void coalescence. Furthermore, a not previously described microstructure anomaly was observed: the presence of pure elemental magnesium crystallites and films on the fracture surface. These are attributed to condensation of magnesium vapour on previously built layers and are a possible reason for the existence of lack-of-fusion defects. The in-depth study of process fundamentals will enable future work on process fume inhibition based on process optimization and alloy composition with the goal of producing parts for biomedical and lightweighting applications.

Effect of Fucoidan on Structure and Bioactivity of Chinese Steamed Bread.

Fucoidan refers to a group of sulphated polysaccharides obtained from brown seaweed, with numerous biological activities. In this study, fucoidan was fortified into Chinese steamed bread (CSB) at different concentrations (0, 1%, 3% and 5%) and the effect of fucoidan on the dough properties, structure properties and bioactivity were investigated. The results showed that fucoidan could change the viscosity of unfermented dough, and a high concentration of fucoidan could remove the free radicals produced by the SH-SS exchange reaction (GS-) in the dough, which significantly reduced the content of disulfide bond and reduced the expanded volume of fermented dough (p < 0.05). In addition, fucoidan forms a physical barrier on the surface of starch particles and hinders the reaction between protein-to-protein; therefore, fucoidan increased the hardness, gumminess and chewiness in CSB, and reduced the specific volume in CSB. Furthermore, the fucoidan-fortified CSB samples were found to have both the ability to significantly reduce the predicted glycemic index (pGI) (p < 0.05) and improve antioxidant activity (p < 0.05). Collectively, these findings could provide a theoretical basis for the applications of fucoidan as a functional component in fermented foods.

Investigation of the influence mechanism of hypersonic flow field environment on thermionic emission efficiency

Electron Transpiration Cooling (ETC) is a novel thermal management method that utilizes thermionic emission to cool the leading edge surface of a hypersonic vehicle. Establishing a thermionic emission model that accounts for the hypersonic flow field environment is imperative for accurately predicting the thermal protection efficiency of ETC. A thermionic emission dual-sheath model was established, considering the impact of hypersonic non-equilibrium flow field particle parameters on thermal electron emission. The virtual cathode threshold was obtained through numerical analysis, considering the influence of particles parameters and surface thermoelectric material parameters in a non-equilibrium flow field. Distribution of sheath potential and particle number density in plasma sheath region were performed at a range of conditions. Thermionic emission efficiency approached 80 % as the plasma ion density was 5 × 20 m−3 and the work function was 2 eV. The results showed that plasma ions have different degrees of neutralization effect on thermal emission electrons depending on the flow field and surface material characteristics, ultimately causing varying surface thermionic emission efficiency.

Preparation of Edible Colorant Lake Using Calcium Carbonate and β-Carotene: Structural Characterization and Formation Mechanism Study.

This study prepared a novel β-carotene colorant lake using calcium carbonate (CaCO3) and investigated the lake formation process and its basic characteristics. Kinetic adsorption analysis confirmed that medium pH (9.3) and medium temperature (40 °C) were more suitable for lake preparation, while desorption occurred, possibly due to crystalline transformation of CaCO3. The isothermal analysis and model fitting results suggested that the β-carotene and CaCO3 particles combined via a monolayer adsorption process driven by physical force. Electrostatic attraction likely participated in the process due to the net negative surface charges of β-carotene dispersion and positively charged groups on the CaCO3 particle surfaces. Ethanol, ultrasonic treatment, and drying method significantly influenced the immobilization efficiency (IE) of β-carotene in the lake and light stability of the lake, without affecting its crystal form. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) curves confirmed absorption of β-carotene onto CaCO3. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated no obvious chemical bonds between β-carotene and CaCO3. Energy-dispersive spectroscopy (EDS) confirmed the presence of β-carotene on surfaces but not in the interior of the CaCO3 particles. The adsorption of β-carotene by calcium carbonate was further confirmed to be a physical adsorption on surface.

Study of the distribution of residual stresses across the surface layer depth following machining through probing hole drilling and digital image correlation

The article aims to study the distribution of residual stresses across the surface layer depth following the machining of test specimens (free orthogonal cutting and burnishing). The machining by cutting and burnishing of 45 steel specimens was carried out using a milling machine with numerical control under varying machining factors. For a comparative analysis, the processes were also modeled via the finite element method using identical experimental values of geometric parameters and machining modes. In order to obtain residual stress distributions across the surface layer depth, probe holes having depths of 0.5; 0.75; 1; 1.5; and 2 mm were drilled. By differentiating the displacement of specimen surface particles, measured using digital image correlation, radial strains around the probe holes were determined. Then, these values were used to determine the residual stress components for each probe hole, and the averaged values of each residual stress component were calculated using the calculation algorithm presented in this article. After burnishing the specimen with a force of 3400 N, the test value of the σx component within the depth range (from the surface) of 0.5–0.75 mm amounted to -250 MPa. Model and experimental distributions of residual stress tensor components across the surface layer depth were obtained following machining via two methods. The experimental values of residual stresses were found to have good convergence with each other and with model distributions at depths up to 1 mm from the machined surface at a drill diameter of 1.7 mm. The proposed approach provides a means to obtain the residual stress distribution across the surface layer depth by drilling probe holes of different depths and estimating radial strains on the specimen surface using the digital image correlation method.

Genotoxicity and heating Performance of VxFe3-xO4 nanoparticles in Health applications

The applications of magnetic nanoparticles (MNPs) as biocatalysts in different biomedical areas have been evolved very recently. One of the main challenges in this field is to design affective MNPs surfaces with catalytically active atomic centres, while producing minimal toxicological side effects on the hosting cell or tissues. MNPs of vanadium spinel ferrite (VFe2O4) are a promising material for mimicking the action of natural enzymes in degrading harmful substrates due to the presence of active V5+ centres. However, the toxicity of this material has not been yet studied in detail enough to grant biomedical safety. In this work, we have extensively measured the structural, compositional, and magnetic properties of a series of VxFe3-xO4 spinel ferrite MNPs to assess the surface composition and oxidation state of V atoms, and also performed systematic and extensive in vitro cytotoxicity and genotoxicity testing required to assess their safety in potential clinical applications. We could establish the presence of V5+ at the particle surface even in water-based colloidal samples at pH 7, as well as different amounts of V2+ and V3+ substitution at the A and B sites of the spinel structure. All samples showed large heating efficiency with Specific Loss Power values up to 400 W/g (H0 = 30 kA/m; f = 700 kHz). Samples analysed for safety in human hepatocellular carcinoma (HepG2) cell line with up to 24h of exposure showed that these MNPs did not induce major genomic abnormalities such as micronuclei, nuclear buds, or nucleoplasmic bridges (MNIs, NBUDs, and NPBs), nor did they cause DNA double-strand breaks (DSBs) or aneugenic effects—types of damage considered most harmful to cellular genetic material. The present study is an essential step towards the use of these type of nanomaterials in any biomedical or clinical application.

Ti compound coating of carbonyl iron particles with controlled surface conditions using a peroxotitanium acid solution for stable magnetic particles

The surface coating of carbonyl iron particles (CIPs) deposited under various surface conditions was examined using a peroxotitanium acid (PTA) solution including H2O2 to obtain highly stable magnetic particles. Upon adsorption on the CIP surfaces, peroxotitanium complexes dehydrated and transformed into TiO2 with hydroxides (TiO2–OH), and the coating morphology significantly changed depending on the surface conditions of the CIPs. The volatile surface impurities that remained on raw CIPs inhibited the adsorption of the complexes, leading to insufficient coating. As oxidation treatment using a boric acid aqueous solution was performed to examine the effects of surface oxides on the coating, the treatment increased the oxide layer thickness and specific surface area of the raw CIPs. During the coating of oxidized CIPs, active surfaces were dissolved in a PTA solution, and γ-FeOOH plate particles were redeposited on the particle surfaces because H2O2 remaining in the PTA solution initially oxidized the active surfaces and then depleted. The results indicated that the treatment with the PTA solution was not suitable for oxidized CIPs with increased specific surface area. A simple dry treatment under vacuum conditions decreased surface impurities on raw CIPs without increasing their specific surface area; consequently, their surfaces were uniformly and sufficiently coated with TiO2–OH. The uniform surface coating decreased the saturation magnetization of the CIPs by only 0.98% and improved their oxidation onset temperature from 369.8°C to 437.1°C, making them suitable for practical use.

Enhanced arc erosion and dynamic welding resistance of Ag-10 wt%Ni@Gr contact material

In this work, a novel hybrid reinforcement Ni@Gr was successfully synthesized by graphene in-situ grown on the surface of Ni particles, and the Ag-10 wt%Ni@Gr contact material was prepared by the combined methode of wet mixing and spark plasma sintering. The effect of graphene incorporation on the electrical performance of Ag-10 wt%Ni@Gr contact material was investigated, and the arc erosion mechanism was discussed as well. As compared to the Ag-10 wt%Ni contact material, the make-arc energy, break-arc energy and the maximum welding force of the Ag-10 wt%Ni@Gr contact material are decreased by 13.2 %, 4.9 %, and 23.1 %, respectively. Moreover, the Ag-10 wt%Ni@Gr contact material displays smaller erosion area, lower surface roughness and less mass loss. It can be ascribed to the increased elastic modulus of the contact surface, reduced bounce effect, lowered make-arc energy and shortened the make-arc duration that are stemmed from the incorporation of graphene. In addition, the incorporation of graphene contributes to the enhanced molten pool viscosity, which can effectively restrain Ag splashing, thereby enhancing arc erosion resistance and welding resistance.

Breath of Danger: Unveiling PM2.5's Stealthy Impact on Cancer Risks.

This article explores the intricate relationship between airborne particulate matter (PM), specifically PM2.5, and its profound impact on human health, emphasising the heightened risks of cancer. Examining the composition and characteristics of PM2.5, such as particle size and surface area, reveals its ability to induce inflammatory injury and oxidative damage. The carcinogenic potential extends beyond respiratory implications, affecting various organs, including the digestive tract, breast, and prostate. In addition to the genotoxic effects of PM2.5, attached polycyclic aromatic hydrocarbons are recognized to be endocrine-disrupting chemicals with specific implications for breast and prostate cancer. Long-term exposure to PM2.5 is associated with increased cancer mortality, with specific risks identified for different cancer types. The linear correlation between cancer risk and PM2.5 concentration calls for a re-evaluation of permissible emission levels. The article concludes by proposing specific mitigating strategies for individuals exposed to elevated PM2.5. It suggests antioxidant-rich diets and supplements, and exploring inhalation-based antioxidant administration as potential protective measures.

Highly hydrophilic H2TiO3 ion sieve with neodymium (Nd) doping enables fast and high-efficiency Li extraction

The metatitanic acid H2TiO3 (HTO) with high selectivity shows potential in lithium extraction from salt lake brine. Nevertheless, the sluggish adsorption kinetics and unsatisfying actual adsorption capacity hinder H2TiO3 industrial application. Herein, a rare earth element Nd-doped H2TiO3 (Nd-HTO-1 %) was synthesized. The crystallinity, morphology, hydrophilicity, adsorption property and mechanism of Nd-HTO-1 % were systematically characterized by a series of techniques. Interestingly, Nd-doping promotes the generation of oxygen vacancies, thereby increasing the density of surface hydroxyl groups and making the surface high-hydrophilic and particle size decreased. After 1 % Nd-doping, high-hydrophilic HTO was obtained with a contact angle of 16.5°. The adsorption capacity of Nd-HTO-1 % increased by 12.5 % compared with HTO, and the equilibrium time of adsorption reduced by half to 4 h. After eight cycles, Nd-HTO-1 % still showed a considerable adsorption capacity of 39.69 mg·g−1. In the meantime, the dissolution loss of titanium is merely 0.14 %, showing excellent cycling stability. Combined with the considerable selectivity exhibiting in Qarhan salt lake brine, it demonstrates potential in utilization of Nd-doped H2TiO3 for lithium extraction from salt lake brine.

Water vapor effects on attrition and elemental migration of iron‐based oxygen carrier in chemical looping combustion

AbstractChemical looping combustion (CLC) offers a novel approach to simultaneous power generation and carbon capture. However, the commercial viability of CLC depends on durable and cost‐effective oxygen carriers (OCs). This study assesses the impact of water vapor (WV) on the attrition of red mud OC, crucial for industrial CLC deployment. Findings indicate a significant reduction in the average attrition rate, from 0.06%/h to 0.03%/h, attributed to the limitation of Fe2O3 reduction, resulting in reduced volumetric and temperature changes in the presence of WV. A developed volume‐based model reveals attrition contributions in the order of chemical &gt; mechanical &gt;&gt; thermal stresses, influencing OC particle surface morphology. Remarkably, the formation of the iron‐oxide layer remains unaffected by WV, reducing agents (CO or H2), or superficial velocities, suggesting scalable iron recovery from attrition with enhanced flexibility in future applications.

Seedless and electroless plating of silver on silica particles by using microreactor

Synthesis of silver nanoshells is still a challenge especially in the absence of surface modification of core particles and/or metal seed decoration on core surfaces. In this study, we applied a microrector to seedless and electroless plating of silver on bare silica particles, and investigated the effects of reaction temperatures and silver ion concentrations on the morphology and surface coverage of silver on the core particle surface. Our experiments demonstrated that the use of the microreactor enabled the one-step direct deposition of silver with a morphology close to complete shells and that silver ion concentrations from 0.2 to 0.5 mM at a moderate temperature of 50 °C produced high coverage and yield. Besides, the mixing sequence of NH3 and HCHO in the synthesis procedure was found to be a key factor to achieve the high silver coverage. In addition, we demonstrated that the addition of polyvinylpyrrolidone (PVP) after the silver shell growth reaction increases the stability without decreasing the reaction rate.