Method For Synthesis Research Articles

Recent advances in continuous flow synthesis of metal-organic frameworks and their composites.

Metal-organic frameworks (MOFs) and their composites have garnered significant attention in recent years due to their exceptional properties and diverse applications across various fields. The conventional batch synthesis methods for MOFs and their composites often suffer from challenges such as long reaction times, poor reproducibility, and limited scalability. Continuous flow synthesis has emerged as a promising alternative for overcoming these limitations. In this short review, we discuss the recent advancements, challenges, and future perspectives of continuous flow synthesis in the context of MOFs and their composites. The review delves into a brief overview of the fundamental principles of flow synthesis, highlighting its advantages over batch methods. Key benefits, including precise control over reaction parameters, improved scalability and efficiency, rapid optimization capabilities, enhanced reaction kinetics and mass transfer, and increased safety and environmental sustainability, are addressed. Additionally, the versatility and flexibility of flow synthesis techniques are discussed. The article then explores various flow synthesis methods applicable to MOF and MOF composite production. The techniques covered include continuous flow solvothermal synthesis, mechanochemical synthesis, microwave and ultrasound-assisted flow synthesis, microfluidic droplet synthesis, and aerosol synthesis. Notably, the combination of flow chemistry and aerosol synthesis with real-time characterization is also addressed. Furthermore, the impact of flow synthesis on the properties and performance of MOFs is explored. Finally, the review discusses current challenges and future perspectives in the field of continuous flow MOF synthesis, paving the way for further development and broader application of this promising technique.

Recyclable Biomimetic Sunflower Pollen-based Photocatalyst for Enhanced Degradation of Pharmaceuticals.

Recent trends in addressing the impending water crisis focus on the development of innovative water treatment methods. This work utilizes pollen as a core template to synthesize highly efficient onion-like photocatalysts for pollutant mineralization. The study showcases a novel electrochemical synthesis method that maintains the structural integrity of pollen, resulting in increased surface area and enhanced photocatalytic activity. After 90-min of visible light irradiation, over 99% mineralization is achieved. These hybrid photocatalysts demonstrate exceptional stability and efficacy in degrading pollutants. The used photocatalysts can be recycled into biopellets with an ash content of less than 7% (weight), moisture content of less than 8% (weight), and a calorific value of ≈22.1±0.3MJkg-1. Additionally, the resulting ashes serve as effective peroxymonosulphate activators for pollutant mineralization. This process offers sustainable waste management while minimizing waste production, providing a practical solution for water purification. The efficacy of this approach in pollutant removal is underscored by mineralization rates exceeding 99%.

Improving thermodynamic stability of double perovskites with machine learning: The role of cation composition

Perovskite materials have exhibited promising potential in various fields, including solar cells, photodetectors, and light-emitting devices, owing to their exceptional optoelectronic properties and low-cost synthesis methods. In this work, the quest for thermodynamic stability in perovskite materials for optoelectronic applications is addressed through a machine learning (ML) approach. We also analyzed the importance of cations in the stability of double perovskites. It was found that the AUC (area under the curve) and accuracy of the LightGBM model in classification are 0.918 and 0.92, respectively, and the RMSE (root mean square error) and R2-score in regression are 0.119 and 0.872, respectively. Subsequently, the model was used to predict the properties of 10 new perovskites with high accuracy. Finally, the analysis of cationic sites revealed that the stability of the double perovskite is significantly affected by the elements occupying the A, B, and B’ sites. Our results provide an optimal machine learning approach for discerning the thermodynamic stability of double perovskites, which can be a useful guide for tuning the properties of perovskite materials.

Flux synthesis of two-dimensional covalent organic frameworks.

Covalent organic frameworks (COFs) are crystalline porous polymers constructed from organic building blocks into ordered two- or three-dimensional networks through dynamic covalent bonds. Attributed to their high porosity, well-defined structure, tailored functionality and excellent chemical stability, COFs have been considered ideal sorbents for various separation applications. The synthesis of COFs mainly employs the solvothermal method, which usually requires organic solvents in sealed Pyrex tubes, resulting in unscalable powdery products and environmental pollution that seriously limits their practical applications. Herein, our protocol focuses on an emerging synthesis method for COFs based on organic flux synthesis without adding solvents. The generality of this synthesis protocol has been applied in preparing various types of COFs, including olefin-linked, imide-linked, Schiff-based COFs on both gram and kilogram scales. Furthermore, organic flux synthesis avoids the disadvantages of solvothermal synthesis and enhances the crystallization and porosity of COFs. Typically, COF synthesis takes 3-5 d to complete, and subsequent washing procedures leading to pure COFs need 1 d. The procedure for kilogram-scale production of COFs with commercially available monomers is also provided. The resulting COFs are suitable for separation applications, particularly as adsorbent materials for industrial gas separation and water treatment applications. The protocol is suited for users with prior expertise in the synthesis of inorganic materials and porous organic materials.

Recent Advances in 1D Nanostructure Assembly and Direct Integration Methods for Device Applications.

In recent years, 1D nanostructure-based devices have achieved widespread usage in various fields, such as sensors, energy harvesters, transistors, and electrodes owing to their exceptional and distinct properties. The pioneering work of Dr. R. S. Wagner at Bell Laboratories in 1964 introduced the vapor-liquid-solid (VLS) process, a powerful synthesis method. Since then, numerous synthesis techniques, including sol-gel, hydrothermal, chemical vapor deposition (CVD), physical vapor deposition (PVD), and more, have been developed. These methods have enabled researchers to effectively control the shape (length and diameter) and material properties of nanowires. However, itwasonly about two decades ago that nanowires started to be widely utilized as key components in functional devices, primarily due to the lack of proper integration methods. Although dozens of integration techniques have been developed, none have emerged as a predominant choice, with each method presenting its own set of advantages and limitations. Therefore, this work aims to categorize these methods based on their working principles and provide a comprehensive summary of their pros and cons. Additionally, state-of-the-art devices that capitalize on the integration of 1D nanomaterials are introduced.

Tunable Wettability of a Dual-Faced Covalent Organic Framework Membrane for Enhanced Water Filtration.

Membrane technology plays a central role in advancing separation processes, particularly in water treatment. Covalent organic frameworks (COFs) have transformative potential in this field due to their adjustable structures and robustness. However, conventional COF membrane synthesis methods are often associated with challenges, such as time-consuming processes and limited control over surface properties. Our study demonstrates a rapid, microwave-assisted method to synthesize self-standing COF membranes within minutes. This approach allows control over the wettability of the surface and achieves superhydrophilic and near-hydrophobic properties. A thorough characterization of the membrane allows a detailed analysis of the membrane properties and the difference in wettability between its two faces. Microwave activation accelerates the self-assembly of the COF nanosheets, whereby the thickness of the membrane can be controlled by adjusting the time of the reaction. The superhydrophilic vapor side of the membrane results from -NH2 reactions with acetic acid, while the nearly hydrophobic dioxane side has terminal aldehyde groups. Leveraging the superhydrophilic face, water filtration at high water flux, complete oil removal, increased rejection with anionic dye size, and resistance to organic fouling were achieved. The TTA-DFP-COF membrane opens new avenues for research to address the urgent need for water purification, distinguished by its synthesis speed, simplicity, and superior separation capabilities.

Rapid Synthesis and Evaluation of Resveratrol-Piperazine Cocrystals by Ultrasound and Microwave Methods.

Resveratrol-piperazine cocrystals have been obtained by ultrasound (US) and microwave-assisted (MW) techniques, using the solution and slurry-based methods, to study the influence of the synthesis method on the resulting cocrystal properties, and scalability of the processes. The potential of these cocrystals is represented by the unique properties of their components, resveratrol, and piperazine, which could be also used in veterinary practice. Resveratrol has antimicrobial, antiviral and anticarcinogenic properties, while piperazine can be used in the treatment of parasitic infections. The influence of ultrasound and microwave-assisted treatment was studied by varying synthesis parameters such as reaction time, temperature, and US or MW power. The main advantage of using these methods is represented by shorter synthesis time compared to conventional methods, resulting in the direct formation of the cocrystals. All samples were obtained in high purity, above 97%. Cocrystal yield correlated positively with ultrasound reaction time, while temperature was not found to influence the microwave synthesis yield up to 50°C, in the case of solution-based methods. MW and US-assisted solution-based methods lead to yields between 52.9 and 68.1%. In the case of the slurry-based method, a minimum reaction time of 5 min leads to the formation of cocrystals with high purity. The resveratrol-piperazine cocrystal's solubility and in vitro antibacterial activity were also evaluated, showing promising results. Ultrasound and microwave-assisted techniques offer a viable alternative for synthesizing resveratrol-piperazine cocrystals with short reaction times, high yield, and purity, suitable for scalable resveratrol-piperazine cocrystals.

Efectividad de la acción de tutela para garantizar la prestación de los servicios de salud a los migrantes venezolanos en el Chocó (2016-2021)

Introduction: This article analyzes the tutela action as an effective tool that allows the protection of the right to health of Venezuelan migrants in Chocó, in addition to studying how the migration of Venezuelans to this department has implied a high demand in the provision of essential services, such as the health service, a provision that has some notable shortcomings in its normal functioning and that has been exacerbated by the high demand generated by the attention to the migrant population. Objective: To establish thenormative tools available to Venezuelan migrants to make their right to health effective through the analysis and synthesis method. Methodology: Qualitative-descriptive, based on a review of electronic journals, articles in scientific journals, as well as consultationof official State pages on the chosen topic. Conclusions: The tutela action is a suitable mechanism used by Venezuelan migrants to protect their right to health, in addition to the Temporary Statute of Protection for Venezuelan Migrants (ETPV) as a tool that allowsdirect access to health services and prevents this right from being undermined.

Drug Loading in Chitosan-Based Nanoparticles

Chitosan nanoparticles (CSNPs) are promising vehicles for targeted and controlled drug release. Recognized for their biodegradability, biocompatibility, low toxicity, and ease of production, CSNPs represent an effective approach to drug delivery. Encapsulating drugs within nanoparticles (NPs) provides numerous benefits compared to free drugs, such as increased bioavailability, minimized toxic side effects, improved delivery, and the incorporation of additional features like controlled release, imaging agents, targeted delivery, and combination therapies with multiple drugs. Keys parameters in nanomedicines are drug loading content and drug loading efficiency. Most current NP systems struggle with low drug loading, presenting a significant challenge to the field. This review summarizes recent research on developing CSNPs with high drug loading capacity, focusing on various synthesis strategies. It examines CSNP systems using different materials and drugs, providing details on their synthesis methods, drug loadings, encapsulation efficiencies, release profiles, stability, and applications in drug delivery. Additionally, the review discusses factors affecting drug loading, providing valuable guidelines for future CSNPs’ development.

Development of modular polymeric nanoparticles for drug delivery using amine reactive chemistry

Curcumin has been explored for its anti-cancer potential, but is severely limited by its hydrophobicity and sensitivity to light and water. In this study, poly (lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) were synthesized to encapsulate curcumin via single emulsion method to improve curcumin stability and bioavailability. The PLGA NPs were coated with oligomeric chitosan (COS) and RGD peptide (a peptide consisting of Arg-Gly-Asp) using amine-reactive chemistry (NHS and EDC). Both COS and RGD had been previously shown to accumulate and target many different types of cancer cells. NPs were characterised based on size distribution, zeta potential, and binding efficiency of RGD peptide. They were also evaluated on encapsulation efficiency, and stability, of curcumin within the NPs. OVCAR-3 cancer cells were treated with COS and RGD-coated PLGA NPs loaded with Coumarin-6 dye for fluorescent imaging of cell uptake. They were also treated with curcumin-loaded NPs to determine cytotoxicity and effectiveness of delivery. The NPs exhibited size distribution and zeta potential within expected values, though binding efficiency of RGD was low. Curcumin-loaded NPs showed significant increase in cytotoxicity over free (unencapsulated) curcumin, and void (empty) NPs, suggesting successful delivery of curcumin as an anti-cancer agent; the performance of COS and RGD coated NPs over bare PLGA NPs was inconclusive, however, optimization will be required to improve formulation during the coating steps. This method of NP synthesis serves as proof of concept for a modular solution to the development of various coated polymeric NPs for other drugs or applications.

Intelligent Systems in The Management of Regional Resources: Benefits for Sustainable Development

The purpose of our research is to analyse intelligent systems, identify their key features in general and in the context of regional resource management in particular; to provide a detailed list of the main intelligent technologies and systems used in regional resource management and the areas of their direct use. The main emphasis should be placed on the benefits of using intelligent systems in the management of regional resources in the context of sustainable development as well as on the problems that can be overcome through the use of intelligent systems. The study should also analyse the negative aspects of the use of intelligent systems in regional resource management. In order to achieve this goal, the general philosophical method, the method of system analysis, synthesis, deduction and induction, dialectical method and formal legal method were used. The findings of the study will serve as a basis for further research and a catalyst for increasing the use of smart technologies, taking into account all the benefits and potential risks.

Facile synthesis of diphosphoryl acetylenes through copper-catalyzed cross coupling

Organic molecules containing 1,2-diphosphonate moiety are of great value in organic synthesis. Diphosphoryl acetylenes (or named as ethyne-1,2-diyldiphosphonates) are a class of molecules utilized for synthesis of diverse phosphorus compounds applicable in multiple fields. However, present stoichiometric methods for the preparation of diphosphoryl acetylenes generally requires multiple steps or harsh conditions. Herein, we report a facile synthesis of diphosphoryl acetylenes, in which the readily available ethynyl phosphonates couple with dialkyl phosphonates through cheap copper catalysis. A series of diphosphoryl acetylenes in symmetric or unsymmetric fashions are facilely prepared. This protocol demonstrates advantages of mild reaction conditions, inert atmosphere-free, cheap catalyst, base-free, and high efficiency to serve as a practical method for synthesis of diphosphoryl acetylenes.

Conjugated Linoleic Acid Production in Pine Nut Oil: A Lactiplantibacillus plantarum Lp-01 Fermentation Approach

Conjugated linoleic acid (CLA) is a class of bioactive fatty acids that exhibit various physiological activities such as anti-cancer, anti-atherosclerosis, and lipid-lowering. It is an essential fatty acid that cannot be synthesized by the human body and must be derived from dietary sources. The natural sources of CLA are limited, predominantly relying on chemical and enzymatic syntheses methods. Microbial biosynthesis represents an environmentally benign approach for CLA production. Pine nut oil, containing 40–60% linoleic acid, serves as a promising substrate for CLA enrichment. In the present study, we developed a novel method for the production of CLA from pine nut oil using Lactiplantibacillus plantarum (L. plantarum) Lp-01, which harbors a linoleic acid isomerase. The optimal fermentation parameters for CLA production were determined using a combination of single-factor and response surface methodologies: an inoculum size of 2%, a fermentation temperature of 36 °C, a fermentation time of 20 h, and a pine nut oil concentration of 11%. Under these optimized conditions, the resultant CLA yield was 33.47 μg/mL. Gas chromatography analysis revealed that the fermentation process yielded a mixture of c9, t11CLA and t10, c12 CLA isomers, representing 4.91% and 4.86% of the total fatty acid content, respectively.

Synthesis and characterization of azo cross‐linked polymer as a new catalyst for the production of hydrogen gas by methanolysis of NaBH4

AbstractThe intensive use of fossil fuels has profound impacts on all ecosystems, primarily contributing to global warming through greenhouse gas emissions. To mitigate these impacts, alternative energy sources like hydrogen are crucial. In this study, azo cross‐linked polymer with 4‐aminophenyl sulfone and resorcinol were synthesized by a green synthesis method. The polymer was extensively characterized by Fourier‐transform infrared spectroscopy, Brunner‐Emmett‐Teller analysis, thermogravimetric analysis, and scanning electron microscopy‐energy dispersive x‐ray spectroscopy analyses. Subsequently, the catalytic performance of the polymer in hydrogen production from NaBH4 via methanolysis was investigated. At this stage, the parameters affecting hydrogen production (catalyst and NaBH4 amounts, MeOH volume and temperature) were systematically studied to determine optimum conditions. The maximum HGR values of the polymer was 13,100 and 27,000 mL min−1 gcat−1 at 30 and 60°C, respectively and its activation energy was 10.45 kJ mol−1. After optimization, the reusability of azo polymer was tested with 5 cycles. The theoretical volume of hydrogen was produced in all 5 cycles. But with each cycle, the hydrogen production time increased. The main purpose of this study was to demonstrate novel azo‐linked polymers with high catalytic activity in hydrogen production. The results revealed significant potential of the polymer for hydrogen generation. Overall, this research highlights the promising role of azo cross‐linked polymers as effective catalysts for hydrogen production, offering new perspectives and pathways towards sustainable energy solutions.

Adsorption characteristics and mechanisms of bisphenol A on novel nitrogen-modified biochar derived from waste masks and biomass.

Resource utilization of waste masks has become an urgent scientific issue. In this work, with sustainably, waste masks and biomass were co-pyrolysis with oxygen limitation to prepare mask-based biochar (MB). Then, urea was introduced to prepare novel nitrogen modified mask-based biochar (NMB) via a one-step hydrothermal synthesis method. The adsorption characteristics of NMB on the emerging environmental pollutant, bisphenol A (BPA), were evaluated via batch adsorption tests. Moreover, the physicochemical properties of the materials were characterized with various advanced techniques. Also, the roles of waste masks and nitrogen modification were explored. The adsorption mechanisms of NMB on BPA were revealed as well as the performance differences between different adsorbents. The results showed that waste masks participated in thermochemical reactions, shaped the microsphere structure of biochar, and increased the types of surface functional groups. The nitrogen modification enriched the surface elemental composition and activated the specific surface area via the mesopore. These would enhance the adsorption performance. The maximum adsorption of BPA by NMB was 62.63mg·g-1, which was approximately 2.35-5.58 times higher than that of the control materials. Temkin model and pseudo-second-order model optimally simulate the isothermal and kinetic adsorption, respectively. The adsorption mechanisms are jointly by physical and chemical adsorption, which mainly includes π-π interaction, hydrogen bonding, intraparticle diffusion, surface adsorption, and ion exchange. After discussion and evaluation, NMB has lower preparation process cost (7.21 USD·kg-1) and safety, with potential for environmental applications. This study aims to expand new ideas for the comprehensive utilization of waste masks and the preparation of eco-friendly materials. Moreover, it provides a theoretical basis for the removal of BPA.

Enhancing Localized Electron Density over Pd1.4Cu Decorated Oxygen Defective TiO2-x Nanoarray for Electrocatalytic Nitrite Reduction to Ammonia.

Electrocatalytic nitrite (NO2 -) reduction to ammonia (NH3) is a promising method for reducing pollution and aiding industrial production. However, progress is limited by the lack of efficient selective catalysts and ambiguous catalytic mechanisms. This study explores the loading of PdCu alloy onto oxygen defective TiO2-x, resulting in a significant increase in NH3 yield (from 70.6 to 366.4µmolcm-2h-1 at -0.6V vs reversible hydrogen electrode) by modulating localized electron density. In situ and operando studies illustrate that the reduction of NO2 - to NH3 involves gradual deoxygenation and hydrogenation. The process also demonstrated excellent selectivity and stability, with long-term durability in cycling and 50h stability tests. Density functional theory (DFT) calculations elucidate that the introduction of PdCu alloys further amplified electron density at oxygen vacancies (Ovs). Additionally, the Ti─O bond is strengthened as the d-band center of the Ti 3d rising after PdCu loading, facilitating the adsorption and activation of *NO2. Moreover, the presence of Ovs and PdCu alloy lowers the energy barriers for deoxygenation and hydrogenation, leading to high yield and selectivity of NH3. This insight of controlling localized electron density offers valuable insights for advancing sustainable NH3 synthesis methods.

Platinum-Ruthenium Bimetallic Nanoparticle Catalysts Synthesized Via Direct Joule Heating for Methanol Fuel Cells.

Platinum-Ruthenium (PtRu) bimetallic nanoparticles are promising catalysts for methanol oxidation reaction (MOR) required by direct methanol fuel cells. However, existing catalyst synthesis methods have difficulty controlling their composition and structures. Here, a direct Joule heating method to yield highly active and stable PtRu catalysts for MOR is shown. The optimized Joule heating condition at 1000°C over 50 microseconds produces uniform PtRu nanoparticles (6.32wt.% Pt and 2.97 wt% Ru) with an average size of 2.0 ± 0.5 nanometers supported on carbon black substrates. They have a large electrochemically active surface area (ECSA) of 239 m2 g-1 and a high ECSA normalized specific activity of 0.295mA cm-2. They demonstrate a peak mass activity of 705.9mA mgPt -1 for MOR, 2.8 times that of commercial 20 wt.% platinum/carbon catalysts, and much superior to PtRu catalysts obtained by standard hydrothermal synthesis. Theoretical calculation results indicate that the superior catalytic activity can be attributed to modified Pt sites in PtRu nanoparticles, enabling strong methanol adsorption and weak carbon monoxide binding. Further, the PtRu catalyst demonstrates excellent stability in two-electrode methanol fuel cell tests with 85.3% current density retention and minimum Pt surface oxidation after 24 h.

The completeness of accreting neutron star binary candidates from Chinese Space Station Telescope

Abstract Neutron star (NS) has many extreme physical conditions, and one may obtain some important informations about NS via accreting neutron star binary (ANSB) systems. The upcoming Chinese Space Station Telescope (CSST) provides an opportunity to search for a large sample of ANSB candidates. Our goal is to check the completeness of the potential ANSB samples from CSST data. In this paper, we generate some ANSBs and normal binaries under CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification model. Although the Precision (94.56 %) of our machine learning model is as high as before study, the Recall is only about 63.29 %. The Precision/Recall is mainly determined by the mass transfer rate between the NSs and their companions. In addition, we also find that the completeness of ANSB samples from CSST photometric data by the machine learning method also depends on the companion mass and the age of the system. ANSB candidates with low initial mass companion star (0.1 M⊙ to 1 M⊙) have a relatively high Precision (94.94 %) and high Recall (86.32 %), whereas ANSB candidates with higher initial mass companion star (1.1 M⊙ to 3 M⊙) have similar Precision (93.88 %) and quite low Recall (42.67 %). Our results indicate that although the machine learning method may obtain a relative pure sample of ANSBs, a completeness correction is necessary for one to obtain a complete sample.

Novel V2O3@N-C cathode for superior aqueous zinc-ion batteries via melamine foam templating

Aqueous zinc-ion batteries (AZIBs) are increasingly garnering attention due to their inherent safety features and the economic benefits of using metallic zinc. Among the promising cathode materials for AZIBs, V2O3-based compounds are extensively studied because of their unique tunnel structure and high energy density. However, the broader application of V2O3-based materials is hindered by several challenges, including sluggish reaction kinetics, poor cycling stability, and the lack of effective methods for large-scale synthesis. In response to these limitations, this study utilizes melamine foam as a self-sacrificing template to develop a V2O3@N-C cathode that aims to enhance the performance of aqueous zinc-ion batteries. The resulting cathode benefits from the uniform dispersion of V2O3 nanoparticles and a trace carbon-coated structure enriched with oxygen vacancies, yielding significant reversible capacity (569.62 mA h g−1 at 0.5 A g−1 and 411.63 mA h g−1 at 20 A g−1) and superior cycling stability (369.66 mA h g−1 after 3200 cycles at 10 A g−1). Additionally, ex-situ characterization techniques have been employed to thoroughly investigate the zinc storage mechanism, offering novel insights for the development of high-performance cathode materials for AZIBs.

A simple method for synthesis and photocatalytic performance of a novel boron doped BiOCl

In this study, a fresh boron-doped B/BiOCl was produced utilizing BPO4 as the boron origin. When exposed to visible light, B/BiOCl demonstrated effective degradation of organic dyes like Rhodamine B (RhB), methyl blue (MB), and basic fuchsin (BF). Their degradation rates surpassed those of BiOCl by 1.7 times for RhB, 3.6 times for MB, and 8.35 times for BF, respectively. Furthermore, the introduction of boron into B/BiOCl notably enhanced its photocatalytic reduction capability towards carbon dioxide, leading to a 3.21-fold increase in CH4 production compared to BiOCl. Analysis results revealed a homogeneous distribution of boron within BiOCl, thereby improving its efficiency in charge-hole separation and adsorption. Consequently, the photocatalytic performance of B/BiOCl was significantly augmented.