Dissolution Characteristics Research Articles

In situ construction of 3D Li channels high-temperature-resistant polymer electrolyte and Li3N-rich interface enabling stable solid-state Li metal battery

High safety, high ion conductivity, and stable interface contacts are of significant importance for the application of solid-state electrolytes (SSEs) in solid-state lithium metal batteries (SSLMBs). In this study, SSEs with high ion conductivity and safety were constructed by in-situ polymerization of poly butyl acrylate (PBA) based electrolytes in the three-dimensional (3D) pores of a polyvinylidene fluoride (PVDF) nanofiber membrane, and embedded with ion conductor succinonitrile (SN), fluorinated ethylene carbonate (FEC), and imidazolium-based ionic liquid (IL). The test results and microscopic structural analysis indicate that SN is uniformly dispersed in PVDF, effectively reducing the crystallinity of solid polymer electrolytes (SPEs) and constructing a 3D interconnected lithium-ion conduction network. Consequently, an ion conductivity of 4.89 mS cm−1 was achieved at 25°C. Meanwhile, density functional theory (DFT) calculations demonstrated that imidazolium-based ionic liquid can adjust the dissolution characteristics of Li+ through weak interactions with the polymer framework and strong coordination with TFSI-. X-ray photoelectron spectroscopy (XPS) characterization revealed that the imidazolium-based ionic liquid can form a stable solid electrolyte interface enriched with Li3N on the lithium-metal surface. The resulting SPEs demonstrated excellent ion conductivity, a high Li+ transfer number (tLi+ = 0.739), and a nanofiber-reinforced interpenetrating framework with a tensile strength of 17.15 MPa. Furthermore, the LiFePO4 (LFP)||Li battery equipped with PBA-PVDF-SN (modified with IL) exhibited excellent electrochemical performance at room temperature with a capacity retention of 87.4 % after 800 cycles at 0.5C.

Anodic Dissolution Behavior of Al Alloys Containing Al6Fe or β-AlFeSi in EmImCl–AlCl3 Electrolyte During Electrorefining

To produce over 99.9% of high-purity Al from Al alloys containing Al6Fe or β-AlFeSi through electrorefining, their anodic dissolution and cathodic electrodeposition characteristics should be clarified. In this study, the anodic dissolution and cathodic electrodeposition behavior of Al–Fe binary and Al–Fe–Si ternary alloys were investigated in an EmImCl–AlCl3 ionic liquid electrolyte at 323 K. Anodic polarization measurements, constant potential electrolysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), field-emission SEM (FE-SEM), and energy dispersive spectroscopy (EDS) were used to study the anode and electrodeposits on the cathode. Constant potential electrolysis showed that Fe dissolved from Al6Fe in the Al–Fe anode at 0.7 V vs Al/Al(III) and from β-AlFeSi in the Al–Fe–Si anode at 1.4 V and was co-deposited with Al on the cathode. Notably, Si did not dissolve from β-AlFeSi at either potential. A combination of controlled anodic dissolution potential and the use of the Al alloy containing β-AlFeSi further suppressed the dissolution and cathodic co-deposition of Fe, affording high-purity Al on the cathode. This suggests that Al alloys with intermetallic compounds that are less likely to dissolve Fe at the anode are optimal for obtaining over 99.9% of high-purity Al from Al alloys containing Fe in the electrorefining method.

AG1®, a Novel Synbiotic, Demonstrates Superior Mineral Bioaccessibility and Bioavailability Compared to a Tablet Multivitamin and Mineral Supplement Using an In Vitro Model of the Upper Gastrointestinal Tract

While traditional multivitamin and mineral (MVM) supplements generally come in tablet form, new powder forms of MVM supplements are available with theoretically higher bioavailability relative to tablet MVM supplements. The purpose of this study was to assess the bioaccessibility and bioavailability of minerals (magnesium (Mg), zinc (Zn), calcium (Ca), and potassium (K)) in a tablet MVM supplement compared to a novel powder Foundational Nutrition supplement (AG1®), containing minerals, vitamins, phytochemicals, and pre-/probiotics, in the upper gastrointestinal tract. The tablet MVM supplement was specifically formulated for this study, with matched mineral contents and identical chemical structures. The adapted Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model was used to assess the bioaccessibility and bioavailability of soluble minerals using a simulated upper gastrointestinal tract and dialysis membrane to mimic human digestion and absorption. The bioaccessibility was assessed at the end of the stomach and duodenum. The bioaccessibility and bioavailability were assessed at 1, 2, and 3 h following dialysis. The preliminary soluble mineral analysis of the tablet (crushed to a powder) and AG1 powder demonstrated significantly higher (p < 0.05) soluble fractions of Zn and Ca, but lower Mg in the AG1 powder vs. the tablet. The total soluble mineral percentages at the stomach and duodenum end were all significantly higher for the AG1 powder vs. the tablet (p < 0.05). Mg, Ca, and Zn were more (p < 0.05) bioaccessible and bioavailable in the powder compared to the tablet during the small intestine simulation. The bioaccessible fraction of K was higher (p < 0.05) only at 3 h for the tablet vs. the powder. These preclinical data demonstrate that the AG1 powder has superior dissolution and disintegration characteristics compared to the tablet, leading to increased bioaccessibility and bioavailability in vitro.

Development of Slow-Releasing Tablets Combined with Persulfate and Ferrous Iron for In Situ Chemical Oxidation in Trichloroethylene-Contaminated Aquifers

Slow-releasing tablets combined with persulfate acting as an oxidant and ferrous iron acting as an activator were manufactured for in situ chemical oxidation. The trichloroethylene (TCE) removal efficiency according to the molar ratio of the oxidizer and activator in the 0, 0.5, 1, 1.5, 2, and 2.5 molar ratio (persulfate: ferrous iron) reactors were 15%, 89%, 90%, 82%, 71%, and 55%, respectively. In a batch reactor injected with an oxidation-activation combined tablet (OACT) and a liquid oxidizing/activator, the TCE removal efficiencies were 100% and 70%, respectively, showing that the tablet form had a high efficiency in contaminant removal. The evaluation of the dissolution characteristics and TCE removal efficiency of OACT 0.5 (tablet with a 1:0.5 molar ratio of persulfate to activator) and OACT 1.0 (tablet with a 1:1 molar ratio of persulfate to activator) under continuous flow conditions showed that the TCE removal efficiency of the OACT 1.0 column was approximately 1.4 times higher than that of OACT 0.5. The longevities of persulfate and ferrous iron of the OACT 1.0 tablet were 43.2 days and 41.7 days, respectively. Thus, OACT 1.0, which was manufactured effectively, was suitable for in situ slow-release chemical oxidation systems.

Study on anodic dissolution behavior and surface evolution of laser-drilled Ni-based superalloys during electrochemical post-processing

Laser drilling is always accompanied by recast layers, micro-cracks, and heat-affected zones, which limit its application in engineering. Due to its unique advantages, such as no heat-affected zones, no residual stresses, and no dependence on the mechanical properties of the materials, electrochemical dissolution has been adopted to remove the laser drilling-induced surface defects. The electrochemical dissolution characteristics and surface evolution of the laser-drilled Ni-based superalloys were studied. The polarization curves and electrochemical impedance spectroscopy (EIS) of the laser-drilled materials and the substrate were measured, indicating that the laser-drilled surface had a smaller corrosion resistance than the original substrate. X-ray photoelectron spectroscopy (XPS) results showed that the laser-drilled surface had a much higher oxygen content than the substrate. Additionally, electric current efficiency curves were obtained to study the anodic dissolution behavior of Ni-based superalloys. An electric current density in the 5–40 A/cm2 range was preferred to enhance the electrochemical dissolution rate. Moreover, the effects of electric current densities and post-processing time on the surface roughness and the recast layer thickness of the laser-processed Ni-based superalloys were investigated using a NaCl and NaNO3 solution electrolyte. The evolution of the surface quality and recast layer thickness were clarified. Furthermore, an anodic dissolution model of the laser-processed surface was established to illustrate the electrochemical post-processing mechanisms. Results revealed that electrochemical dissolution could completely remove the laser drilling-induced surface defects in 20 s using a 12.5 wt.% NaNO3 solution electrolyte and a 40 A/cm2 electric current density. Finally, an electrochemical post-processed surface with surface roughness (Ra) of 1.7 µm and without a recast layer was achieved. Micro holes without recast layers and Ra of 0.69 µm were obtained with high efficiency using laser processing and electrochemical post-processing.

Sensitization of polymethacrylate resist with adding acid-generating promoters upon exposure to EUV light

With the advancement of EUV lithography, the development of higher performance resist materials has been required. Recently, the EUV sensitivity of chemically amplified resists has been improved by adding an acid-generating promoter (AGP) such as DTS (p-tolyl diphenyl sulfone). However, the details of the mechanism of sensitivity enhancement were still unclear. In this study, we investigated the EUV sensitivity, dissolution characteristics during development after EUV irradiation, and patterning characteristics by electron beam lithography with the addition of AGP to the acrylate polymers. The addition of DTS showed an increase in sensitivity with DTS concentration. We also discuss other than the increase in initial acid yield that lead to enhanced sensitivity by addition of DTS.

Molecular dynamics study on the dissolution characteristics and cluster formation of Li2CO3 in supercritical water

Recycling lithium from electronic waste is the focus of current research on waste treatment and resource utilization, and environmentally friendly supercritical water technology is an important recycling method. It is necessary to study the dissolution and precipitation characteristics of lithium salt in supercritical water. In this paper, molecular dynamics (MD) and quantum mechanics (QM) were used to study the dissolution properties of Li2CO3 in supercritical water and the structure and properties of clusters. The potential mean force (PMF), radial distribution function (RDF), and coordination number (CN) showed that the solubility of Li2CO3 in supercritical water was more affected by temperature, and the trend was opposite to that of temperature, and the ion pairs in solution were mostly in CIP state. Cluster searches were performed for the cluster configurations and their distribution probabilities of CIP states in supercritical water. The electrostatic potential distribution and intermolecular interactions of the initial cluster configuration in the supercritical solution of Li2CO3 are calculated by the QM method. In this study, the cluster configuration with a planar symmetry structure accounted for the largest proportion, and the lowest free energy was −431.86308400 a.u.

Numerical study on dissolution characteristics of solid-phase oxygen control in liquid LBE systems based on the porous media model

For the proper design and operation of lead oxide mass exchanger (PbO MX), the dissolution kinetics of PbO in flowing liquid Lead-bismuth eutectic (LBE) needs to be determined. A computational fluid dynamics (CFD) method of the PbO MX was established. The solid-phase oxygen control part of the MX is PbO spheres packed bed, which is regarded as a porous media in the simulation calculation. The oxygen mass transfer process between PbO spheres packed bed and liquid LBE was simulated by a porous media model with the species transport model. The relationship between the dissolution rate of MX and the flow rate, temperature and initial oxygen concentration is predicted. The dissolution rate of PbO increases exponentially with increasing temperature of LBE. Besides, the dissolution rate of oxygen is positively correlated with the LBE flow velocity. In the specific oxygen concentration range, the MX inlet oxygen concentration has little effect on the dissolution rate. The smaller the porosity of PbO spheres packed bed has, the smaller the dissolution rate of oxygen is. Furthermore, when the porosity is constant, the dissolution rate of oxygen increases with the increase of the height of the packed bed of PbO spheres.

Solubility, thermodynamic investigation and molecular dynamics simulation of guanidine hydrochloride in four binary solvents

Solubilities of guanidine hydrochloride (GuHCl) in organic solvents are of great importance for its development and optimization of industrial process. The study of the dissolution characteristics of GuHCl in DMF/2-meoxyethanol/methanol/NMP + n-propanol at different temperatures were experimentally investigated by using laser monitoring method. Results showed that GuHCl solubilities were observed to be increasing with the increment in experimental temperature and rising with higher mass fraction of DMF/2-meoxyethanol/methanol/NMP. Molecular dynamics (MD) simulation technique was utilized to reveal the microscopic behaviors of GuHCl and solvent mixtures and its effect on the dissolving capability of GuHCl in involved solvent systems. Also, five thermodynamic models were selected to regress the observed GuHCl equilibrium solubility. A comparison of the experimental values with corresponding estimated data indicated that the modified Apelblat equation provided the most excellent correlation in modelling GuHCl solubility. Finally, through the analyses of enthalpy change, entropy change and Gibbs free energy change, the dissolution thermodynamic features were evaluated.

Single-tablet-scale direct-compression: An on-demand manufacturing route for personalized tablets

Today’s pharmaceutical industry is facing various challenges. Two of them are issues with supply chain security and the increasing demand for personalized medicine. Both can be addressed by increasing flexibility and a more decentralized approach to pharmaceutical manufacturing. In this study, we present a setup that provides flexibility in terms of supplied raw materials and the product, i.e., a direct-compression setup for personalized tablets operating at a single-tablet-scale. The performance of the implemented single-tablet-scale technology for dosing and mixing was investigated. In addition, an analysis of the critical quality attributes (CQAs) of immediate release ibuprofen and loratadine tablets was performed. The developed dosing device achieved acceptance rates of > 90 % for doses ≥ 20 mg for various pharmaceutical powders. Regarding the vibratory mixing process, a dependency of the performance on the applied frequencies and acceleration was observed, with 100 Hz and ∼ 90 G performing best, yet still exhibiting varying mixing efficacies depending on the granular system. The tablets produced met U.S. Pharmacopeia requirements regarding mechanical stability and dissolution characteristics. Given these results, we consider the developed setup a proof of concept of a tool to provide personalized tablets to patients while minimizing the dependency on complex supply chains.

Preparation and Characterization of Bilastine Solid Self-Nanoemulsion using Liquisolid Technique

Background: Supersaturable self-nanoemulsion (S-SNE) is an approach for dealing with low oral bioavailability problems. Bilastine (BL) is a selective H1-antihistamine with a bioavailability of 59%. Objective: To use a liquisolid technique to transform liquid BL S-SNE into powder so that both the S-SNE and liquisolid procedures could be used. Methods: Oleic acid, tween 60, transcutol, and soluplus were used to make the liquid BL-loaded S-SNE that was adsorbed onto the Avicel PH101 and Aerosil 200 admixtures. In vitro dissolution and powder flow characteristics were tested. SEM, DSC, X-ray diffraction, FT-IR analysis, and the average droplet size after dispersion in 0.1N HCl were also utilized to define the best formula's solid state. Results: The best liquid-solid composition, SS-F2, is composed of oleic acid, tween 60, transcutol, soluplus, Avicel 101, and Aerosil 200, with a liquid SNE to Avicel 101 ratio of 1.5:1 and an Avicel 200 to Aerosil 200 ratio of 10:1. SS-F2 displayed good flowability and a significant improvement in drug dissolution, with 100% of the medication released after 60 min compared to 62.27% of the marketed BL tablets. According to the solid-state investigation of formula (SS-F2), BL was shown to be in a solvated state in the solidified nanosystem, with no interactions with the excipient used. It also formed a nanoemulsion with mean droplet sizes of 77.57 nm and a PDI of 0.4178, which was similar to liquid S-SNE. Conclusion: The liquisolid technique is a potential method for solidifying a liquid self-emulsifying system while preserving self-nanoemulsion characteristics and increasing dissolving rate.

A novel method to improve the morphology of Bi2212 film by PVA-assisted Pechini sol-gel method

Bi2212 high-temperature superconducting thin films (HTSFs) have emerged as the most promising material for terahertz (THz) devices due to their intrinsic Josephson effect. Enhancing the surface smoothness of these films is crucial for their practical application. In this study, metal nitrates were utilized as the raw material to prepare Bi2212 HTSFs on SrTiO3 (100) substrates using the Pechini sol-gel method. The chelating agent ethylenediamine tetraacetic acid (EDTA) and the surfactant polyvinyl alcohol (PVA) were employed to improve the dissolution characteristics of Bi2212 solution. The influence of various parameters such as sintering temperatures, surfactant concentrations, and metal ion ratios was systematically investigated to assess the phase purity, crystallinity, surface morphology, and electrical properties of the Bi2212 superconducting thin films. The results demonstrated that a higher concentration of PVA led to reduced solubility of the Bi2212 solution. Notably, when the PVA concentration was set at 1 %, the fabricated Bi2212 thin film exhibited exceptional epitaxial properties, enhanced Bi2212 phase purity, reduced surface roughness, and higher Tc. These outcomes provide valuable insights for the development of Bi2212 HTSFs in superconducting devices, as they serve as a reference point for achieving optimal film characteristics.

Elemental dissolution characteristics of granite and gabbro under high-temperature water-rock interactions

In the process of developing hot dry rock (HDR) through enhanced geothermal systems (EGS), it is necessary to inject circulating water to complete thermal energy extraction. However, the injected water will react with the high-temperature rock and produce mineral dissolution, which can destroy the artificial reservoir and affect the development of geothermal energy. To explore the influence of temperature on the solution composition and mineral dissolution after water-rock reaction, this study conducted water-rock interaction experiments on gabbro and granite at different heat treatment temperatures. Subsequently, the changes of solution composition and mineral dissolution with temperature after the reaction were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and XRD. The results demonstrated that Si, Na, Ca, K, Al, and Mg did not enter the aqueous solution at the same dissolution rate. Si was the primary solute in the solution, mainly resulting from the dissolution of quartz, and the dissolution rates of metallic elements were lower. In the granite-water interaction system, metallic elements such as Na, K, Ca, and Al showed a tendency to enter the solution at low temperatures, i.e., 150–180 °C, and the dissolution rate of Si reached its peak when the water was close to the supercritical state. With the increase in temperature, the dissolution rates of Si and metallic elements showed an initial increasing trend followed by a decrease. When water is in the subcritical to the supercritical state, abrupt fluctuations in the physical properties of water can strongly affect the dissolution of minerals or rocks. The results of this study provide insights into rock corrosion fatigue and mineral scaling in EGS water environment.

Microfluidic investigation on asphaltene interfaces attempts to carbon sequestration and leakage: Oil-CO2 phase interaction characteristics at ultrahigh temperature and pressure

CO2 huff-n-puff is a potential approach to improve the oil displacement efficiency in the deep reservoirs, which can achieve carbon sequestration and efficient oil production, simultaneously. However, the fundamental understanding of carbon mass transport, sequestration and leakage mechanism in deep geological reservoirs at the microscopic pore scale is still ambiguous. In this work, we innovatively designed a precise CO2 huff-n-puff microfluidic experiment under ultrahigh temperature and pressure conditions (55 MPa, 115 °C) to study the microscopic mechanism of CO2 utilization, storage and leakage (CUSL) in pore scale. Moreover, we proposed the quantitative analysis method for oil-CO2 interaction behavior to explicit dissolution and extraction characteristics, pressure threshold and interface stability by introducing Pseudo-Color algorithm and relevant parameters such as dynamic oil swelling factor, contact angle and gray value. Then, the pore-scale dynamics of the fluid interaction mechanism during the soak and puff process were quantitatively characterized, corresponding to the carbon sequestration efficiency of crude oil continuously exposed to scCO2 and the leakage risk with step-down production, respectively. The experimental results indicate that during the huff process, the oil-CO2 phase behavior characteristics at 115 °C can be divided into swelling, immiscible extraction and miscible extraction regions, which are coordinately controlled by dissolution mechanism, capillary effect and vaporization mechanism. Moreover, ultrahigh temperature oil generally requires higher pressure to start extraction and miscibility (Pext = 6.38 and 15.96 MPa, MMP = 9.71 and 23.73 MPa, T = 50 and 115 °C, respectively), while the asphaltene precipitation pressure Pasp is lower. At ultrahigh temperatures, the oil-CO2 interaction also enters the contact angle fluctuation region in advance, and the morphology of asphaltene particles is single, fine and uniform. When the soaking time is 36 min, the non-extractable oil component gradually evolves into a carbon sequestration interface. During the subsequent puff process, the more stable the carbon sequestration interface in the smaller blind end, the lower the leakage risk, corresponding to the leakage pressure difference of up to 40.93 MPa. This work has important practical significance for deep resource extraction and CUSL industrial application.

Synergistic effect and mechanism of lithium slag on mechanical properties and microstructure of steel slag-cement system

Replacement of cement with solid waste is an important method for conserving natural resources and reducing CO2 emissions. In this study, steel slag and lithium slag were used to replace cement to address the low activity of steel slag, which limits its large-scale utilization. The compressive strength, flow properties, dissolution characteristics, hydration products, and microstructure of composite cementitious materials containing steel slag and lithium slag were investigated by ICP-OES, XRD, TG, FTIR, SEM and MIP. The results showed that the addition of lithium slag into the cementitious material with steel slag improved the compressive strength. The lithium slag consumed a large amount of portlandite and promoted hydration of the steel slag to produce more C-(A)-S-H. Furthermore, the porosity and pore size distribution were optimized, the most probable pore size was reduced, and the pore complexity was increased. This research provides a solution for comprehensive use of steel slag, which contributes to high-value green utilization of solid waste.

In vitro pharmaco-equivalence analysis of diclofenac potassium oral film-coated tablet relative to marketed generics

Context: Diclofenac potassium, a potent member of the non-steroidal anti-inflammatory drugs (NSAIDs) that is commonly used for acute analgesia and multiple inflammatory conditions, has various marketed tablet brands available. However, quality parameters of tablet dosage forms may vary across different brands. Aims: To evaluate critical quality attributes, including in vitro dissolution characteristics of four diclofenac potassium immediate-release (IR) tablet brands (labeled A–D) collected from Saudi Arabia market. Methods: All brands were tested for conformity with the United States Pharmacopoeia, through evaluation of weight variation, hardness, friability, disintegration, and dissolution. Dissolution profiles were compared using model-dependent and-independent approaches relative to the innovator A. Results: Data showed that the samples were compliant in terms of weight variation, hardness and friability. Disintegration time (DT) for brands B and D was below USP specifications whereas that of brand C was higher. Brand B and D had higher dissolution efficiency (DE) and similar mean dissolution time (MDT) compared with innovator. Brand C had lower DE and greater MDT compared with innovator. Weibull model of drug-release kinetics was found to be the best fit for all samples. Conclusions: In summary, brand C, unlike brands B and D, appears to relatively undermine the purpose of a diclofenac IR formulation, given its longer DT, lower DE and slower dissolution release compared with the innovator. These differences are potentially attributable to variations in tablet additives and manufacturing processing across different pharmaceutical industries.

Design and Characterisation of Rosuvastatin Calcium Nanosuspension Loaded Transdermal Patch

Objective: The present investigation highlights the formulation and evaluation of nanosuspension-loaded transdermal patches of poorly soluble antilipidemic drug (rosuvastatin) Methods: Dissolution characteristics of drug was improved by preparation of nanosuspension employing precipitation–ultrasonication technique using a different blend of water-soluble film forming polymers such as hydroxyl propyl methyl cellulose (HPMC K4M), Eudragit and were further characterized by fourier transformation infrared spectroscopy (FTIR), Malvern zetasizer and SEM. Propylene glycol and tween 80 were used as stabilizers. Based on the particle size of the formulation, the best one of NS4 was selected and fabricated into the transdermal patch by solvent casting method. The prepared formulations were evaluated for various parameters like drug excipient compatibility, appearance, morphology, thickness, tensile strength, folding endurance, % elongation, % moisture content, % moisture uptake, % drug content, in-vitro drug permeation, and stability studies were performed for the optimized formula according to the ICH Q1A (R2) guideline under 4°C and 25°C RH for three months. Results: Amongst all formulation, P4 transdermal patches were considered the optimized formulation. It has the highest in-vitro drug permeation (86.01±0.05%), thickness (0.86±0.09), weight uniformity (475.0±8.60 mg), folding endurance (279.3±9.39), moisture uptake (7.06±1.75%), moisture content (6.81±2.34 %) and stable formula Conclusion: Therefore, transdermal patches were considered to be potentially suitable for the sustained release of drugs to improve patient compliance.

Molecular dynamics simulation on the dissolution and diffusion characteristics of FeCrAl alloy in liquid LBE

Lead-bismuth eutectic (LBE) corrosion-resistant materials are crucial for the development of future fourth-generation nuclear reactors, and the dissolution and diffusion of material components are important processes in LBE corrosion-resistant materials. FeCrAl alloy is an important structural material for fourth-generation reactors, and it is essential to study its dissolution and diffusion processes in liquid LBE. Molecular dynamics simulations (MD) were used to investigate the mutual diffusion process between the FeCrAl alloy and liquid LBE. The dissolution and diffusion abilities of Fe, Cr, and Al atoms in liquid LBE were evaluated using mean-square displacement (MSD) and diffusion activation energy (DAE). Fe atoms exhibited the highest degree of diffusion, while Al atoms showed the lowest degree of diffusion, resulting in a distinct difference in the elemental distribution at the solid–liquid interface (SLI). There was a significant difference in the depth of penetration of Pb and Bi atoms into the FeCrAl alloy matrix, with Bi atoms penetrating deeper. Furthermore, there is a thermal vibration process during the invasion of Pb and Bi atoms into the FeCrAl alloy matrix, which promotes the invasion process of Pb and Bi atoms. In addition, an increase in temperature exacerbates the diffusion of Fe, Cr, and Al atoms in liquid LBE and the process of Pb and Bi atom invasion into the FeCrAl alloy matrix. Our research may contribute to the design of future nuclear-grade FeCrAl alloy and the development of next-generation reactors.

Complete Desensitization of Aluminum–Magnesium Alloys via Boron Addition

We address here an important issue related to sensitization effects in Al5083 by mitigating the grain boundary precipitation of the beta phase and demonstrate that the addition of a small amount of boron to Al5083 impedes the precipitation of the beta phase, Al3Mg2, also known as the Samson phase. In Al–Mg alloys, the precipitation of Al3Mg2 usually occurs at grain boundaries in the temperature range of 50 to 200 °C from a supersaturated solid solution of Al–Mg and makes these alloys susceptible to intergranular corrosion and stress corrosion cracking. Upon boron addition, we show, using transmission electron microscopy, that a diboride phase, AlMgB2, forms at grain boundaries instead of the beta phase upon extended annealing at 150 °C. This diboride phase does not dissolve in saltwater, suggesting it is less anodic relative to the matrix. To quantify and compare the dissolution characteristics, we carried out nitric acid mass loss test for Al5083 samples containing 3 wt.% boron treated at 190 h at 150 °C, and fully sensitized Al5083 samples containing 0.0 wt.% boron. We estimate the mass loss to be 4 mg/cm2 for boron containing samples as compared to the mass loss of 45 mg/cm2 for samples without boron, indicating that the addition of boron is highly effective in suppressing the susceptibility to intergranular corrosion in Al5000 series alloys. This provides a potential route to minimize the longstanding problem of ship structure sensitization.

Study on anaerobic fermentation of waste activated sludge to produce volatile fatty acids by thermal–rhamnolipid treatment

AbstractBACKGROUNDThe extracellular polymer and cell wall of waste activated sludge serve as chemical barriers for anaerobic fermentation, limiting the recycling and utilization of organic carbon contained in the sludge. To improve the efficiency of anaerobic fermentation, this paper proposes thermal–rhamnolipid (T‐RL) pretreatment technology and systematically discusses the effect of T‐RL treatment on the anaerobic fermentation of waste activated sludge for acid production from the perspective of organic matter dissolution characteristics, total volatile fatty acid (VFA) content, composition and microbial changes.RESULTST‐RL treatment significantly promoted the dissolution of organic matter in sludge, with soluble chemical oxygen demand solubilizing to 6097.78–7375.56 mg L−1, soluble carbohydrates solubilizing to 207.38–274.74 mg L−1, and the dissolution of soluble proteins and DNA also at a high level. Both treatment factors significantly promoted the enrichment of acid‐producing microorganisms, especially acetic acid‐producing microorganisms. The best VFA production conditions of T‐RL treatment were 60 mg g−1 total solids and 70 °C, and the yield was 3294.96 mg L−1. Compared with thermal and RL treatments, the optimum yield of T‐RL treatment increased by 33.16% and 22.06%, respectively. The VFA components in the T‐RL group were mainly acetic acid and propionic acid. Under optimal conditions, the proportion of acetic acid and propionic acid reached 77%.CONCLUSIONT‐RL treatment can promote sludge disintegration and organic matter conversion through the coupling effect of thermal and RL treatments, providing sufficient and high‐quality substrate for acid‐producing microorganisms, effectively enriching VFA producers, and thus improving the efficiency of anaerobic fermentation for VFA production. This treatment technology will provide some beneficial references for the future utilization of sludge resources. © 2023 Society of Chemical Industry (SCI).