Separation Factor Research Articles

Use of green polar aprotic solvents TamiSolve® NxG, DMSO and methyl-THF for the synthesis of asymmetric polyimide-based biogas purification membranes

Valorization of biogas to biomethane through membrane-based purification of its multi-component stream primarily consisting of CH4 and CO2, holds significant potential as a crucial renewable energy source. Industrial membrane units classically comprise of membranes synthesized using non-solvent induced phase separation (NIPS), with polymer processing typically performed using conventional solvents, such as N-N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), etc. However, use and subsequent waste handling of these solvents present significant hazards, due to their toxicological nature, therefore calling for a shift to employ safer and ‘greener’ materials to facilitate sustainable production of these membranes. In current work, a novel and sustainable methodology for synthesis of CO2/CH4 gas separation flat-sheet asymmetric membranes was developed with commercially available Matrimid® 5218 polyimide, using TamiSolve® NxG, dimethylsulfoxide (DMSO) and 2-methyltetrahydrofuran (MeTHF) as green solvent medium. NIPS thermodynamic and kinetic aspects of the novel system were fundamentally analyzed through determination of ternary phase diagrams and viscosity profiles. Membranes were systematically tested for gas separation performance by varying Tamisolve-DMSO-MeTHF solvent ratios. Mixed gas CO2/CH4 separation factors in the range of 13 to 41, along with CO2 permeances upto 186 GPU were achieved. Furthermore, chemical crosslinking was applied in view of plasticization resistance of the membranes. Matrimid® membranes crosslinked with hyperbranched polyethylenimine (PEI) successfully displayed stability against CO2-induced plasticization upto CO2 feed partial pressures of 22 bar. The developed membrane synthesis method provides a sustainable framework for synthesizing polyimide-based membranes with tunable gas separation performances.

PDMS membrane incorporated by zeolites with tunable pore chemistry for dimethyl carbonate/methanol azeotropic mixture separation

The separation of organic-organic azeotropic mixtures is important in the petrochemical, agrochemical, and pharmaceutical industries, which is energy-intensive by using the current distillation technology. Pervaporation process is energy-efficient for azeotropic separation, while lacks of high-performing membrane materials. In this work, to realize efficient separation of dimethyl carbonate/methanol azeotropic mixtures, a benchmarked membrane, polydimethylsiloxane (PDMS), was incorporated by zeolites with tunable pore chemistry. Specifically, MFI-type zeolite was grafted by alkyl chains with different carbon numbers (C1, C4, C8), thereby providing tunable transport channels for organic molecules. Based on systematic characterizations (e.g., sorption and LF-NMR) and permeation test, we found that the organophilic alkyl chain can trap organic molecules into the zeolitic pores while may also hinder the organic diffusion through the zeolite due to the steric hindrance effect. The PDMS mixed-matrix membrane (MMM) with optimized C1-grafted MFI loading as high as 50 wt% exhibited separation factor of 3.6, and permeation flux of 11.5 kg m-2 h-1 for 30 wt% DMC-methanol azeotropic mixture at 40 °C. With slightly higher separation factor, the flux of PDMS MMM is 1.5-fold higher than that of the pure PDMS membrane. This work highlights the critical role of filler pore chemistry on the solution-diffusion transport and thus performance enhancement of MMM.

Development and Psychometric Properties of a Tool Related to the Adoption of Desirable Behaviors in the Consumption of Sugar-sweetened Beverages in Children Based on the Social Cognitive Theory

Background Consumption of sugar-sweetened beverages is associated with chronic diseases such as diabetes and cardiovascular disorders and other severe negative health consequences and is one of the challenging issues in the field of nutrition in today's societies. This study was conducted with the aim of designing a psychometric questionnaire in relation to the consumption behavior of sugar-sweetened drinks in children. Methods In this cross-sectional research, 607 students were selected and included in the study by multi-stage cluster sampling from the first-year secondary schools covered by the Urmia Department of Education. Waltz's method was used to design the questionnaire, and based on a targeted review of the literature and questionnaires related to nutrition behavior, an initial questionnaire with 51 items was designed. After confirming the face and content validity of the questionnaire by 15 members of the expert panel, construct validity steps were performed using exploratory factor analysis. Finally, the internal reliability of the questionnaire was determined by calculating Cronbach's alpha. Results The first version of the questionnaire was designed with 51 items and all the items were retained in the psychometric process during content validity. The content validity index and ratio were calculated to be higher than 0.79 and 0.6, respectively. Based on the exploratory factor analysis, the number of items in the questionnaire remained at 51, and the dimensions of the questionnaire were categorized into 6 factors: perceived barriers, self-efficacy, self-regulation, social support, preventive behaviors, and reinforcing behaviors, with a predictive power of 56,261 and in repeating the exploratory factor analysis for items with a different nature from other factors, 3 separate factors were identified: the physical health dimension of outcome expectations, negative outcome expectations, and positive outcome expectations with a predictive power of 54.667. The internal reliability of the questionnaire items was accepted and confirmed with Cronbach's alpha coefficient above 0.70. Conclusion The final questionnaire with 51 items has the ability to be used by various researchers due to the strength of the factorial structure and suitable psychometric properties.

Research Progress in Tritium Processing Technologies: A Review

Recent advancements in tritium separation technologies have significantly improved efficiency, particularly through the integration of vapor phase catalytic exchange (VPCE), liquid phase catalytic exchange (LPCE), and combined electrolysis catalytic exchange (CECE) methods. Combining these techniques overcomes individual limitations, enhancing separation efficiency and reducing energy consumption. The CECE process, which integrates electrolysis with catalytic exchange, offers high separation factors, making it effective for high-concentration tritiated water treatment. Solid polymer electrolyte (SPE) technology has also gained prominence for its higher efficiency, smaller equipment size, and longer lifespan compared to traditional alkaline electrolysis. While electrolysis offers high separation factors, its high energy demand limits its cost-effectiveness for large-scale operations. As a result, electrolysis is often combined with other methods like CECE to optimize both energy consumption and separation efficiency. Future research will focus on improving the energy efficiency of electrolysis for large-scale, low-cost tritiated water treatment.

Efficient Separation of Hydroxylamine from Metal Ions by PIM-ED Process

Selective separation of hydroxylamine (HA) from metal ions to prepare high-purity HA remains a challenge. In this study, given that HA can react with carbonyl compounds, TTA (thenoyltrifluoroacetone) was screened as a carrier to prepare the polymer inclusion membrane (PIM), which was used to separate HA from metal and inorganic acid ions. The experimental results demonstrated that the PIM exhibited good selectivity for HA. During the PIM process, the proton gradient served as a driving force to transport NH2OH(I). The electrodialysis (ED) process was used to efficiently and continuously provide proton gradient without introducing other ions, which coupled with PIM to separate HA. Under the optimum conditions, the separation factors of NH2OH(I)/Na(I) and NH2OH(I)/K(I) were 30.81 and 35.11; the purity of HA was 99.4%, indicating that the PIM-ED process can be used for high-purity preparation of HA.

Lithium Extraction by Electrodialysis: Effect of Co-Occurring Ions for Application in Brine Processing

Abstract Lithium (Li) is considered a critical material because of growing Li-ion battery demand and 90% of global production occurring in Australia, Chile, and China. Li-ion (Li+) extraction from brine uses large areas for evaporation and precipitation. Membrane separation can extract lithium with minimal water losses. However, the effect of brine composition on Li+ transport across different commercial membranes in electrodialysis (ED) separations remains a pressing knowledge gap. This study aimed to evaluate co-occurring ion effects (Na+, Mg2+, Ca2+) on ED Li+ extraction using different commercial membranes. Li+ extraction performance was evaluated for varying current densities in binary solutions using a single-stack ED cell comprised of a standard anion exchange membrane and either a standard cation exchange (CEM), monovalent-selective CEM, or nanofiltration (NF) membrane. Li+ selectivities were highest for the monovalent-selective CEM, followed by NF and then standard CEM. Monovalent contaminants remain an extant challenge for Li+ extraction using all membranes tested. Selectivity factors for Li+ over divalent reached 6.8 (SLi/Mg) and 56.7 (SLi/Ca) at 2.8 mA/cm² for the monovalent-selective CEM. These divalent separation factors were achieved without Ca precipitation/fouling; Li+/Mg2+ and Li+/Ca2+ ratios increased from 0.5 in the feed (for both ions) to 5.0 and 3.5 in the permeate.

Effects of Forest Types on Soil Particulate Organic Carbon Contents and Distribution Along a Subtropical Climate Transect in China

ABSTRACTThe influence of various types of forests on the storage of C in forest soil is significantly more concerned in recent decades, as these ecosystems are crucial for mitigation of the effects of global climate change. Nevertheless, uncertainties remain surrounding the impact of different forest types on the stability and distribution of SOC. The influence of forest types on the content and distribution characteristics in CPOC, FPOC, MAOC fractions. Importantly, we found that the forest types significantly affect the content of SOC (p = 0.020), POC (p < 0.001), and MAOC (p < 0.001), there was a significant forest type × region interaction effect (SOC: p = 0.019, POC: p = 0.025, and MAOC: p = 0.003). The random forest analysis showed that FPOC and MAOC were the main factors affecting SOC which indicated FPOC and MAOC have higher relative importance to SOC. The subtropical forests POC and MAOC storage and distribution are driven by separate environmental factors. POC storage in subtropical forests is mainly controlled by exogenous C inputs and soil transformation processes, while subtropical forests’ MAOC storage is primarily controlled by constraints on C inputs and C stabilization mechanisms. Different environmental factors result in forest types with faster decomposition rates having more C stored in the total soil C pool in the MAOC. Altogether, this research emphasizes the importance of different forest types to SOC pools and provides valuable information for the distribution and stability of SOC fractions in different forest types.

Multicenter Validation of the Ocular Myasthenia Gravis Rating Scale Questionnaire.

Ocular myasthenia gravis (OMG) causes disabling ocular symptoms of ptosis and diplopia, but a validated disease-specific patient-reported outcome measure (PROM) has not been reported. We sought to validate a novel PROM for OMG, OMG Rating Scale Questionnaire (OMGRate-q), as a measure of visual functioning to support patient-centered care. This was a prospective study of patients aged 18 years and older with OMG receiving care at 3 medical centers (January 2022-October 2023). The 10-item OMGRate-q was administered, and response data were analyzed using exploratory factor analysis followed by Andrich rating scale model fitting. Poorly fitting items were eliminated, and the model was refit to produce the final items, item locations, and thresholds. Latent scores (theta) were estimated, test-retest reliability was established with repeat measures, and correlation with other myasthenia gravis PROMs was measured. Of the 134 patients included in the study, 45 (33.6%) were women, 99 (73.9%) were White, and the median age (interquartile range [IQR]) was 64.6 years (52.6-73.9 years). A ptosis-related item showed significant item-trait deviation (p < 0.001) and was kept as a separate factor from the remaining diplopia-related items. After excluding this item, there were no misfitting items. Theta estimation for the diplopia scale ranged from -3.47 to 5.51 with median = -0.53 (IQR -2.33, 0.72). Test-retest reliability of the OMGRate-q diplopia subscale was high (intraclass correlation coefficient = 0.95 [95% CI 0.90-0.98]) and of the ptosis item was good (weighted κ = 0.56). No significant differences were observed in OMGRate-q diplopia subscale scores or the ptosis item between the 3 sites (diplopia p = 0.44; ptosis p = 0.32). OMGRate-q scores were moderately to highly correlated with the Myasthenia Gravis Quality of Life 15 questionnaire (n = 122; diplopia: r = 0.68, p < 0.001; ptosis: r = 0.48, p < 0.001) and Myasthenia Gravis Impairment Index (n = 130; diplopia: r = 0.76, p < 0.001; ptosis: r = 0.77, p < 0.001). OMGRate-q length was acceptable to most participants (125/130 [96.2%]), and the questionnaire was completed in 80.7 (±45.2) seconds. The OMGRate-q is a valid and reliable disease-specific PROM for OMG that may be used to facilitate patient-centered research and care. However, the OMGRate-q emphasizes the impact of diplopia on visual functioning with a single separate item measuring ptosis. Future studies are needed to determine OMGRate-q responsiveness to disease-state changes and how to add measures of ptosis to this scale or whether a separate measure is needed.

Enhancing CO2 Oversaturation in the Confined Water Enables Superior Gas Selectivity of 2D Membranes.

Due to the global demands on carbon neutralization, CO2 separation membranes, particularly those based on two-dimensional (2D) materials, have attracted increasing attention. However, recent works have focused on the chemical decoration of membranes to realize the selective transport, leading to the compromised stability in the presence of moisture. Herein, we develop a series of 2D capillaries based on layered double hydroxide (LDH), graphene oxide, and vermiculite to enhance the oversaturation of CO2 in the confined water for promoting the membrane permselectivity. By employing the dielectric spectroscopy as a probe to unveil oversaturation, the dissolved CO2 can be enhanced by up to ten times facilitated by water confined in the 2D capillary, particularly constructed by the LDH, endowing the uprise of CO2/N2 separation factor by 43 times. Therefore, our work opens an avenue to the future design of selective membranes by modulating the confined water beyond chemical modification.

Recovery of Li Through Selective Adsorption on Two Types of Calix[4]arene Derived Adsorbents

ABSTRACT Recovery of Li is one of urgent issues owing to exponential increase of Li demand of Li-ion battery. More efficient and selective reagents for Li recovery have been required. Calixarene as a host oligomer was focused on this purpose, and it was applied to adsorptive reagents. Two types of adsorbents incorporating trialkyl monoacetic acid derivatives of calix[4]arene through either impregnation or crosslinking were synthesized. The impregnated adsorbents were synthesized by impregnation of four trialkyl monoacetic acid derivatives of calix[4]arene into macroporous Ambelite XAD-7. The crosslinked adsorbents were synthesized by crosslinking of three trialkyl monoacetic acid derivatives of debutylated calix[4]arene each other using sym-trioxane under an acidic condition. Their adsorption behaviors and Li+ selectivities over other alkali metal ions were investigated. Incorporation of the ligand into the adsorbents had a negligible effect on the time required to reach equilibrium. The impregnated adsorbents exhibited extremely high Li+ selectivity over other alkali metal ions that reflected those of the incorporated ligand, whereas the crosslinked adsorbents exhibited Cs+ selectivity and mixed effects arising from incomplete dehydration and ion discrimination. The adsorption of alkali metal ions was driven by ion-exchange mechanism. The apparent adsorption equilibrium constants for alkali metal ions on both adsorbents and the separation factors between the metal ions were estimated. It was found that three alkyl branches affected the adsorption efficiency, together with separation efficiency.

LiMn2O4 Nanoparticles In Situ Embedded in Carbon Networks for Lithium Extraction from Brine via Hybrid Capacitive Deionization.

Highly selective and efficient extraction of lithium from brine is considered a promising strategy to alleviate the imbalance between supply and demand of lithium resources. However, it is still challenging for lithium ions (Li+) recovery from brine. In this work, LiMn2O4 nanoparticles embedded in situ in carbon networks (LMO-C) derived from metal-organic frameworks by incomplete calcination have been developed for lithium extraction from brine via the hybrid capacitive deionization (HCDI) process. The adsorption capacity of the obtained LMO-C for Li+ is 3.5 mmol g-1, while the separation factor reaches 24.5 at a high Mg:Li ratio of 20. The extraction and insertion of Li atoms in the LiMn2O4 lattice were visually confirmed. In addition, it is found that the synergistic effect between the LMO and the carbon networks is retained in the surface of LMO-C, and the above effect effectively promotes the migration of Li+ and the sustainability of the HCDI process. This work is believed to provide a guidance for the design and synthesis of high-performance HCDI materials for the practical lithium extraction from brine.

Increased 238Pu Production in Proliferation-Resistant U-10Zr Fuel Produced from Reprocessed Uranium Containing Unseparated 237Np

The sodium-cooled fast reactor (SFR) is a potential candidate for the future production of clean sustainable energy. Some SFR designs planned for construction will use high-assay low-enriched uranium (HALEU) metal fuel enriched up to around 19.75%. However, fast reactor technology faces several criticisms, such as its ability to produce weapons-grade plutonium, the possibility of facility diversion from peaceful use to the production of nuclear weapons–usable materials, and the risk of incentivizing the construction of domestic fuel enrichment programs. To compete with traditional light water reactors (LWRs), SFR technology utilizing HALEU fuel should be developed to be proliferation-resistant and sustainable. In this study, the Serpent 2 Monte Carlo reactor physics code was used to simulate and compare alternative HALEU fuel options that could be implemented to reduce proliferation risk. As part of the comparison, nonpeaceful plutonium diversion pathways were considered. By evaluating its attractiveness for diversion from peaceful use to the production of nuclear weapons–usable material, it was shown that the proliferation resistance of SFR technology utilizing HALEU fuel can be improved. The operation of a once-through fuel cycle SFR utilizing HALEU fuel was simulated, and the performance and material attractiveness of various U-10Zr fuel options were compared. Currently, hundreds of thousands of tons of spent fuel from the operation of LWRs are stored across the world. Most of the heavy metal in this spent nuclear fuel is comprised of reusable uranium and plutonium. Re-enrichment of reprocessed uranium (RepU), with or without the presence of unseparated 237Np, for the production of SFR fuel is one way to simultaneously improve uranium resource utilization and enhance proliferation resistance due to the co-enrichment of 236U and 237Np. The presence of these isotopes in fresh HALEU fuel can increase 238Pu production even at low reactor burnup. Due to its high decay heat and spontaneous neutron emission, 238Pu decreases material attractiveness for nuclear weapons construction. Directly doping fresh fuel with preseparated 237Np requires the separate storage of neptunium, introducing its own nuclear security requirements and proliferation risks. Additionally, due to uncertainty in the separation factor between RepU and neptunium, some neptunium impurities will inevitably remain in RepU following separation. Therefore, this study examined the impact of unseparated 237Np on the production and depletion of U-10Zr fuel. A parametric study comparing fuel options of varying 237Np weight fractions was conducted, and proliferation scenarios considering both clandestine and overt diversion of discharged fuel were considered.

Multisite synergistic interaction induced selective adsorption of CB5-Ti3C2T2 complex for strontium ion: A combined theoretical and experimental study.

In this work, we use a well-defined water-soluble macrocyclic molecule cucurbit[5]uril (CB5) to modify 2D Ti3C2T2 MXene and assemble a novel high-performance adsorbent CB5-Ti3C2T2 for Sr ion by density functional theory and experimental methods. The structural stabilities of two distinct types of CB5-Ti3C2T2 (T = F, O and OH) complexes, i.e., CB5-Ti3C2T2(V) and CB5-Ti3C2T2(P) configurations are proved by binding energy and ab initio molecular dynamics (AIMD) simulations. Calculations of adsorption properties reveal that all the considered CB5-Ti3C2T2 complexes can act as efficient adsorbents for Sr ion, among which CB5-Ti3C2O2 complex possesses the best performance. The high affinity (the calculated adsorption energies < -7.6 eV) and selectivity of CB5-Ti3C2T2 complex for Sr ion are attributed to the synergistic effect between CB5 molecule and Ti3C2T2 MXene in the adsorption process, which arises from the multisite interactions of portal carbonyl groups of CB5 and surface functional groups of Ti3C2T2 towards Sr. Finally, CB5-Ti3C2T2 complex was successfully synthesized, and experimental results confirm its synergistic effect, good selectivity and high removal efficiency for Sr ions. In the treatment of strontium-containing wastewater with low concentrations, the distribution coefficient and decontamination factor of CB5-Ti3C2T2 for Sr were determined to be as high as 2.88 × 105 mL/g and 144.9, respectively, and the separation factor (SFSr/Ca) achieved a notable value of 67. 5. This work is expected to present a new strategy for the construction of high-performance MXene-based adsorbent for radionuclide elimination.

COMPOSITE HYDROPHOBIC PDMS-SILICALITE-1 MEMBRANES FOR THE SEPARATION OF THE ACETONEBUTANOL-ETHANOL (ABE) FROM AN AQUEOUS MIXTURE BY PERVAPORATION

One of the challenges in butanol production is its separation from aqueous acetone-butanol-ethanol (ABE) because of the azeotropic nature of the mixture and the high energy needed to recover the solvents from the dilute solution. Currently, pervaporation has been one of the most studied recovery approaches due to its selectivity when highly hydrophobic membranes are used, as well as the reduced energy demand involved in applying vacuum instead of conventional distillation. In this study, an ABE aqueous mixture was separated by pervaporation using pure and composite (mixed matrix and layered) PDMS + silicalite-1 membranes. For mixed matrix membranes, silicalite-1 crystals were dispersed in PDMS (20, 40, 60, and 80 wt%), then spin-coated using toluene as a solvent, and finally characterized by SEM-EDS, XRD, TGA, and FTIR. A total flux of 35.65 g/m2×h and a separation factor towards butanol of 22.60 was achieved with membranes prepared using 500 mg of (80 wt% + PDMS/mL of toluene) and 1,000 mg of silicalite-1 (80 wt% + PDMS/ mL of toluene), respectively. The high flux is related to the larger free volume in the polymer resulting from the incorporation of hydrophobic crystals of silicalite-1, thus improving the selectivity towards butanol. Also, the physicochemical properties of the membranes are paramount to high performance in the recovery of the ABE mixture, particularly the appropriate silicalite-1 loading.

Novel Approach for Efficient Separation of Primary Amines Using Supercritical Fluid Chromatography.

Efficient enantioselective separation is a critical process in pharmaceutical and chemical industries for the production of chiral compounds. Herein, we developed a novel approach for the efficient enantioselective separation of primary amines using supercritical fluid chromatography (SFC) with a commercially available SFC column, Cel1. The key factors of separation, including cosolvent ratios, total cosolvent percentages, and temperature, were systematically assessed in this study. It revealed that utilization of a cosolvent mixture consisting of methanol and isopropanol in a 1:3 (v/v) ratio with a low total cosolvent percentage of 5% resulted in superior retention and selectivity. Additionally, it was observed that maintaining mid-range temperatures at 30 and 35°C achieved optimal balance between retention and efficiency. Employment of commercially available SFC columns streamlined the separation process, reducing analysis time and labor. This study highlights the effectiveness of SFC as a powerful tool for conducting high-throughput enantioselective separations in pharmaceutical and fine chemical industries.

Recovery of iron as hematite and separation of trivalent lanthanide ions from spent hard disk magnet leach liquor using [P66614][Cy272] ionic liquid.

The widespread use of neodymium-iron-boron (NdFeB) magnets has raised concerns about the environmental impact of their disposal, prompting the need for sustainable recycling strategies. Traditional solvents used in recycling are toxic and flammable, making them risky to use. Ionic liquids are safer and greener options with low vapor pressure, high stability, and less flammability. This study introduces an eco-friendly recycling approach utilizing the [P66614][Cy272] ionic liquid to selectively extract iron and recover rare earth elements (REEs) from the leach liquor of waste NdFeB magnets. Pre-treatment processes enhanced metal concentration before leaching, including demagnetization, grinding, and screening. Optimal leaching conditions: 2 mol L-1 HCl, 80 °C, 10 g L-1 pulp density, and 90 minutes, resulted in complete leaching of REEs (Dy, Pr, Nd), iron, and boron. Using 0.01 mol L-1 [P66614][Cy272] ionic liquid, 100% of the iron was removed from the leach liquor with minimal co-extraction of REEs (∼4%). Precipitation of iron leading to Fe2O3 (hematite) after calcination and is verified through XRD and SEM-EDS analyses. The ionic liquid also enabled 81.1% recovery of HCl from the leach liquor, reducing neutralization needs and operational costs. Subsequent REEs separation using 0.01 mol L-1 [P66614][Cy272] ionic liquid demonstrated high selectivity, achieving separation factors of 18.55 (Dy/Pr) and 15.52 (Dy/Nd) at pH 2.03. Dy(iii) was successfully separated from NdFeB leach solutions using counter-current extraction, leaving 6.0 mg L-1 in the raffinate, requiring two extraction stages at a 2 : 3 organic-to-aqueous phase (O/A) ratio. The reusability of the ionic liquid further enabled a sustainable, closed-loop recycling process. This approach highlights the potential for integrating ionic liquids into green technologies for NdFeB magnet recycling, ensuring resource recovery while minimizing environmental impact.

Completely preorganized bis-lactam-1,10-phenanthroline ligands with high stability for efficient separation of Am(III) over Eu(III).

N,O-Heterocyclic ligands such as 2,9-diamide-1,10-phenanthroline dicarboxamide (DAPhen) and bis-lactam-1,10-phenanthroline (BLPhen) exhibit excellent separation performance for Am(III) and Eu(III) in high-level liquid waste. However, DAPhen-based ligands show poor extraction capacity, and BLPhen ligands suffer from decomposition in acidic solutions, which hinders their application in practical separation processes. To develop ligands with superior performance, two new completely preorganized and highly stabilized bis-lactam-1,10-phenanthroline (BLPhen) ligands with varying alkyl chain lengths were synthesized, demonstrating exceptional extraction and separation of Am(III) from Eu(III) with maximum separation factors of 68 and 53, respectively. DFT calculations and various analytical techniques confirmed that the ligands form 1 : 1 complexes with metal ions, with stronger bonding interactions for Am(III), highlighting their potential for spent nuclear fuel processing.

Related factors and safety of reaching the therapeutic target of warfarin after heart valve surgery in hospitalized patients: A retrospective cohort study.

Warfarin is a commonly employed anticoagulant drug aimed at rapidly reaching the optimal international normalized ratio (INR), potentially reducing the hospitalization time in clinical settings. However, limited research has been conducted on the influencing factors and the safety implications of promptly reaching the target INR range in patients with valvular heart disease who have undergone valve replacement or repair. The present study aimed to assess the factors related to the safety considerations of rapidly reaching the target INR range in patients treated with warfarin. A retrospective cohort investigation was performed on hospitalized patients treated with warfarin between July 2022 and June 2023. Patient data were gathered from patient documentation. A total of 175 patients were included in the current study. The mean time to reach an effective INR threshold was 9.8 days (median, 3-28 days). Age >65 years, body mass index <24 kg/m2, no smoking history and warfarin starting dose ≥3 mg/day were separate factors linked to rapidly reaching the effective INR threshold for warfarin management. The occurrence of INR levels ≥4 was significantly elevated among patients who reached the effective INR threshold more rapidly, while bleeding incidents were not significantly different. Inpatients aged >65 years, those with a body mass index <24 kg/m², no smoking history or prescribed a starting warfarin dosage ≥3 mg/day had a higher likelihood of rapidly reaching the effective INR threshold with warfarin. To enhance safety for these patients, enhanced INR tracking and suitable warfarin dosage adjustments are suggested following the initiation of oral warfarin therapy.

Selective Crystallization Separation of Uranium(VI) Complexes from Lanthanides.

The limited availability of uranium (U) resources poses significant challenges to the advancement of nuclear energy. Recycling uranium from spent fuel is critical, but the coexistence of lanthanides (Ln) complicates the extraction process significantly. Here, we present an N/O ligand, (E)-N'-(pyridin-2-ylmethylene) picolinohydrazide (PYPH), designed for the selective recovery of U(VI) over Ln(III/IV) in acidic environments. 3,6-Bis(2-pyridinyl)-1,2,4,5-tetrazine (BPTZ) and N,N-dimethylformamide (DMF), when subjected to heat, gradually generate PYPH and formic acid in aqueous solution; this process can be employed for uranium recovery. This approach, known as the in situ reactive extraction technique, enhances capture capacity, selectivity, and acid resistance while effectively mitigating interference from Ce(IV). At pH 3 and 0.1 M HNO3, separation factors for the binary Ln(III/IV) and U(VI) systems exceeded 103 and 102, respectively, achieving purities exceeding 99%. Monocrystalline structure analysis revealed two-dimensional planar coordination complexes, demonstrating their exceptional selectivity. This study underscores the potential of PYPH in uranium recovery from spent fuel and proposes new avenues for developing innovative separation strategies for lanthanides and actinides (An) using structural and theoretical modeling.

Kinetics, isotherms, and thermodynamics: caesium ion adsorption on titanate nanostructures from aqueous solutions

ABSTRACT Releasing radioactive caesium ions (Cs+) from nuclear industries into natural water bodies poses significant environmental challenges. Meanwhile, various treatment methods have been applied to mitigate the presence of this detrimental pollutant in water sources. The utilisation of adsorption technology using nanoscale materials seems to hold promising potential for reducing Cs+ levels in water resources. This research has been conducted to evaluate the caesium ions adsorption using synthesised titanate nanotubes (TNT) and titanate nanofibers (TNF) produced via the hydrothermal method under highly alkaline conditions. The XRD, SEM, TEM, BET, TGA, and Zeta-potential analysis were used to characterisation the synthesised absorbents. Adsorption of Cs+ ions on TNT and TNF based on various parameters such as contact time, pH, initial concentration, adsorbent weight, and temperature have been investigated through batch experiments. The adsorption kinetics are best described by the pseudo-second-order model, whereas the Langmuir model is more consistent with adsorption isotherms. The maximum adsorption capacity for caesium ions was determined to be 175.44 mg.g−1 and 104.17 mg.g−1 at 298 K for TNT and TNF, respectively, with 80% and 72% removal rates. The separation factor (RL) value for TNT is 0.5370, and for TNF, it is 0.6570, confirming the favourability of adsorption. Thermodynamic assessments indicate that adsorption onto both adsorbents is favourable, spontaneous, and endothermic. The physisorption is the most likely mechanism for adsorption. A comparative assessment showed that titanate nanotubes outperform titanate nanofibers in terms of caesium ion adsorption capacity and efficiency.