Synthesis Of Frameworks Research Articles

Synthesis and Characterization of Ni based Metal Organic Framework for Enhancing the Removal of Typical Organic Dyes

In this report we present a simple synthesis of a nickel-based metal organic framework (MOF-Ni) at the room temperature using a solution of dimethylformamide (DMF), ethanol and distilled water. The MOF-Ni synthesized in various solvents displayed numerous different properties and advantages over other materials including easy synthesis procedure, good crystallinity, rigidity, and robust chemical stability. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA) were employed to analyze the as-synthesized MOF-Ni. The as-obtained MOF-Ni was used to investigate its adsorption kinetics of red telon dye (RTL) molecules. The effects of time (30–270 min), initial RTL concentration (20–300 mg/L), adsorbent dose (2–50 mg), solution pH (2–12), and temperature (10–80 °C) were investigated. The pseudo-first order rate equation was able to provide the best description of the adsorption kinetics data in the studied time scale. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms, and the isotherm constants were also determined. Dye adsorption turned out to strongly depend on pH, and a low pH was found to increase the amount of adsorbed dyestuff. Compared with other samples, MOF-Ni synthesized in (DMF ​+ ​C2H5OH ​+ ​H2O) had a significantly enhanced adsorption ability for RTL dye. The MOF-Ni high adsorption capacity for RTL dye was attributed to the electrostatic attraction/repulsion phenomena. Moreover, MOF-Ni showed an improved stability at 370, 417, and 423 °C temperatures. The results obtained through our experiments suggested that our porous MOF-Ni microstructures synthesized in DMF ​+ ​C2H5OH ​+ ​H2O have potential applications for treating wastewaters containing RTL dyes.

Visual Ship Image Synthesis and Classification Framework Based on Attention-DCGAN

To improving ship image generation and classification tasks, a deep convolution generative adversarial network based on attention mechanism (ADCGAN) model was constructed. The rectified linear unit (ReLU) activation function was adopted, and three Deconv layers and Conv layers were added to both the generator and discriminator. Subsequently, an attention mechanism was added to the generator, while spectral normalization (SN) was added to the discriminator. Mean squared error (MSE) was used as loss function to stabilize the training process. Furthermore, ship classification tasks were performed using the generated ship images by end-to-end training of the classification network, enabling ship data augmentation and co-learning with other tasks. Experimental results on the Ship700 and Seaship7000 datasets demonstrate that the ADCGAN model can generate clear and robust ship images, with PSNR, LIPIPS, MS-SSIM values of 20.279 and 27.523, 0.596 and 0.096, 0.781 and 0.947, respectively. The effectiveness of the proposed method in ship image classification tasks was also verified, providing a data foundation for other collaborative tasks.

Controlled Localized Metal-Organic Framework Synthesis on Anion Exchange Membranes.

Metal-organic framework (MOF) films can be used in various applications. In this work, we propose a method that can be used to synthesize MOF films localized on a single side of an anion exchange membrane, preventing the transport of the metal precursor via Donnan exclusion. This is advantageous compared to the related contra-diffusion method that results in the growth of a MOF film on both sides of the support, differing in quality on both sides. Our proposed method has the advantage that the synthesis conditions can potentially be tuned to create the optimal conditions for crystal growth on a single side. The localized growth of the MOF is governed by Donnan exclusion of the anion exchange membrane, preventing metal ions from passing to the other compartment, and this leads to a local control of the precursor stoichiometry. In this work, we show that our method can localize the growth of both Cu-BTC and ZIF-8 in water and in methanol, respectively, highlighting that this method can used for preparing a variety of MOF films with varying characteristics using soluble precursors at room temperature.

Facile synthesis of novel porphyrin-based covalent organic frameworks integrated with Au nanoparticles for highly sensitive detection of organophosphorus pesticide residues

Organophosphorus pesticides (OPs) residues in agricultural products such as vegetables, fruits, and grains pose a threat to food safety and human health. In this work, a novel and highly sensitive electrochemical biosensor was developed for OPs residues detection in real sample, based on the immobilization of acetylcholinesterase (AChE) by electrostatic adsorption on a glassy carbon electrode (GCE) modified with composite nanomaterials of porphyrin-based covalent organic frameworks (p-COFs) loaded by gold nanoparticles (AuNPs) and poly (diallyldimethylammonium chloride) (PDDA). Due to the synergistic effect of p-COFs, AuNPs and PDDA, the fabricated biosensor displayed the remarkable properties with the high electrocataytic activity, and excellent biocompatibility, resulting in a significant signal amplification of as-prepared biosensor. Under optimized conditions, the biosensor showed excellent sensing performances for the detection of methyl parathion (MP), with wide linear ranges from 1.9 × 10−9–3.8 × 10−5 M and a low detection limit as low as 2.3 × 10−10 M, as well as the satisfactory selectivity, excellent reproducibility, anti-interference properties and good stability. It was also successfully applied to the monitoring of MP content in vegetables and fruits, which may be explore a new opportunity for the potential utilization in analysis field.

Design and synthesis of broadband absorption covalent organic framework for efficient artificial photocatalytic amine coupling

Developing highly active materials that efficiently utilize solar spectra is crucial for photocatalysis, but still remains a challenge. Here, we report a new donor-acceptor (D-A) covalent organic framework (COF) with a wide absorption range from 200 nm to 900 nm (ultraviolet-visible-near infrared light). We find that the thiophene functional group is accurately introduced into the electron acceptor units of TpDPP-Py (TpDPP: 5,5’-(2,5-bis(2-ethylhexyl)−3,6-dioxo-2,3,5,6-tetrahydropyrrolo [3,4-c]pyrrole-1,4-diyl)bis(thiophene-2-carbaldehyde), Py: 1,3,6,8-tetrakis(4-aminophenyl)pyrene) COFs not only significantly extends its spectral absorption capacity but also endows them with two-photon and three-photon absorption effects, greatly enhancing the utilization rate of sunlight. The selective coupling of benzylamine as the target reactant is used to assess the photocatalytic activity of TpDPP-Py COFs, showing high photocatalytic conversion of 99% and selectivity of 98% in 20 min. Additionally, the TpDPP-Py COFs also exhibit the universality of photocatalytic selective coupling of other imine derivatives with ~100% conversion efficiency. Overall, this work brings a significant strategy for developing COFs with a wide absorption range to enhance photocatalytic activity.

Continuous Solvothermal Synthesis of Metal-Organic Framework (Cu-BTC) Nanoparticles Using a Microstructured Mixer Equipped with Double-Tube, Swirl, and Contraction Flow Channels

Continuous Solvothermal Synthesis of Metal-Organic Framework (Cu-BTC) Nanoparticles Using a Microstructured Mixer Equipped with Double-Tube, Swirl, and Contraction Flow Channels

Synthesis of sulphone-infused two-dimensional microporous covalent organic frameworks involving Ni(II) porphyrin and sulfur powder for the photocatalytic generation of N-benzylidene benzylamine and their derivatives

In this article, the synthesis of a two-dimensional sulfone-based microporous COF, Ni-P has been executed via C-S coupling of nickel (II) tetra(p-bromophenyl) porphyrin with sulfur powder in the presence of the catalytic amount of CuI and benzotriazole in an inert atmosphere (N2) at 120 °C for 7–8 hrs. The authenticity as well as physiochemical properties of the compound have been investigated using FT-IR, XPS, XRD, TGA, SEM, and BET. The optical band gap (1.9 eV) and electrochemical band gap (2.1 eV) of Ni-P have been calculated through UV–vis and cyclic voltammetric study which finds Ni-P a suitable candidate for photocatalytic study. In the chemical transformation reactions, Ni-P shows an excellent conversion rate of benzylamine for the generation of N-benzylidene benzylamine through oxidative coupling (yield ∼ 99 %). In the photostability study, even after 5 times, it shows good recyclability as evidenced by FT-IR and XRD data.

Carbon and metal based magnetic porous materials - Role in drug removal: A Comprehensive review

Development of effective adsorbents for the removal of contaminants from wastewater is indispensable due to increasing water scarcity and a lack of pure drinking water, which are prevailing as a result of rapid industrialization and population growth. Recently, the development of new adsorbents and their effective use without generating secondary waste is receiving huge consideration. In order to protect the environment from primary and secondary pollution, the development of adsorbents from wastes and their recycling have become conventional practices aimed at waste management. As a result, significant progress has been made in the synthesis of new porous carbon and metal-organic frameworks as adsorbents, with the objective of using them for the removal of pollutants. While many different kinds of pollutants are produced in the environment, drug pollutants are the most vicious because of their tendency to undergo significant structural changes, producing metabolites and residues with entirely different properties compared to their parent compounds. Chemical reactions involving oxidation, hydrolysis, and photolysis transform drugs. The resulting compounds can have detrimental effects on living beings that are present in soil and water. This review stresses the development of adsorbents with adjustable porosities for the broad removal of primary drug pollutants and their metabolites, which are formed as a result of drug transformations in environmental matrices. This keeps adsorbents from building up in the environment and prevents them from becoming significant pollutants in the future. Additionally, it stops secondary pollution caused by the deterioration of the used adsorbents. Focus on the development of effective adsorbents with flexible porosities allows for the complete removal of coexisting contaminants and makes a substantial contribution to wastewater management. In order to concentrate more on the development of flexible pore adsorbents, it is crucial to comprehend the milestones reached in the research and applications of porous magnetic adsorbents based on metal and carbon, which are discussed here.

Early stages of covalent organic framework formation imaged in operando

Covalent organic frameworks (COFs) are a functional material class able to harness, convert and store energy. However, after almost 20 years of research, there are no coherent prediction rules for their synthesis conditions. This is partly because of an incomplete picture of nucleation and growth at the early stages of formation. Here we use the optical technique interferometric scattering microscopy (iSCAT)1–3 for in operando studies of COF polymerization and framework formation. We observe liquid–liquid phase separation, pointing to the existence of structured solvents in the form of surfactant-free (micro)emulsions in conventional COF synthesis. Our findings show that the role of solvents extends beyond solubility to being kinetic modulators by compartmentation of reactants and catalyst. Taking advantage of these observations, we develop a synthesis protocol for COFs using room temperature instead of elevated temperatures. This work connects framework synthesis with liquid phase diagrams and thereby enables an active design of the reaction environment, emphasizing that visualization of chemical reactions by means of light-scattering-based techniques can be a powerful approach for advancing rational materials synthesis.

Synthesis and Application of a pH-Responsive Functional Metal-Organic Framework: In Vitro Investigation for Delivery of Oridonin in Cancer Therapy.

Oridonin (Ori) is a naturally existing diterpenoid substance that mainly exists in the Chinese medicinal plant Rabdosia rubescens. It was previously found to possess intriguing biological properties; however, the quick clearance from plasma and limited solubility in water restricts its use as a drug. Several metal-organic frameworks (MOFs), having big surfaces and large pores, have recently been considered promising drug transporters. The zeolitic imidazolate framework-8 (ZIF-8), a form of MOF consisting of 2-methylimidazole with zinc ions, is structurally stable under physiologically neutral conditions, while it can degrade at low pH values such as in tumor cells. Herein, a nanosized drug delivery system, Ori@ZIF-8, was successfully designed for encapsulating and transporting oridonin to the tumor site. The drug loading of the prepared Ori@ZIF-8 was 26.78%, and the particles' mean size was 240.5 nm. In vitro, the release of Ori@ZIF-8 exhibited acid sensitivity, with a slow release under neutral conditions and rapid release of the drug under weakly acidic conditions. According to the in vitro anti-tumor experiments, Ori@ZIF-8 produced higher cytotoxicity than free Ori and induced apoptosis in A549 cancer cells. In conclusion, Ori@ZIF-8 could be a potential pH-responsive carrier to accurately release more oridonins at the tumor site.

Microwave Assisted Fast Synthesis of a Donor‐Acceptor COF Towards Photooxidative Amidation Catalysis

AbstractThe synthesis of covalent organic frameworks (COFs) at bulk scale require robust, straightforward, and cost‐effective techniques. However, the traditional solvothermal synthetic methods of COFs suffer low scalability as well as requirement of sensitive reaction environment and multiday reaction time (2–10 days) which greatly restricts their practical application. Here, we report microwave assisted rapid and optimized synthesis of a donor‐acceptor (D−A) based highly crystalline COF, TzPm‐COF in second (10 sec) to minute (10 min) time scale. With increasing the reaction time from seconds to minutes crystallinity, porosity and morphological changes are observed for TzPm‐COF. Owing to visible range light absorption, suitable band alignment, and low exciton binding energy (Eb=64.6 meV), TzPm‐COF can efficaciously produce superoxide radical anion (O2.−) after activating molecular oxygen (O2) which eventually drives aerobic photooxidative amidation reaction with high recyclability. This photocatalytic approach works well with a variety of substituted aromatic aldehydes having electron‐withdrawing or donating groups and cyclic, acyclic, primary or secondary amines with moderate to high yield. Furthermore, catalytic mechanism was established by monitoring the real‐time reaction progress through in situ diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) study.

Microwave Assisted Fast Synthesis of a Donor-Acceptor COF Towards Photooxidative Amidation Catalysis.

The synthesis of covalent organic frameworks (COFs) at bulk scale require robust, straightforward, and cost-effective techniques. However, the traditional solvothermal synthetic methods of COFs suffer low scalability as well as requirement of sensitive reaction environment and multiday reaction time (2-10 days) which greatly restricts their practical application. Here, we report microwave assisted rapid and optimized synthesis of a donor-acceptor (D-A) based highly crystalline COF, TzPm-COF in second (10 sec) to minute (10 min) time scale. With increasing the reaction time from seconds to minutes crystallinity, porosity and morphological changes are observed for TzPm-COF. Owing to visible range light absorption, suitable band alignment, and low exciton binding energy (Eb=64.6 meV), TzPm-COF can efficaciously produce superoxide radical anion (O2⋅-) after activating molecular oxygen (O2) which eventually drives aerobic photooxidative amidation reaction with high recyclability. This photocatalytic approach works well with a variety of substituted aromatic aldehydes having electron-withdrawing or donating groups and cyclic, acyclic, primary or secondary amines with moderate to high yield. Furthermore, catalytic mechanism was established by monitoring the real-time reaction progress through in situ diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) study.

Unique Reactivity of the 1,4-Bis(silyloxy)-1,3-cyclopentadiene Moiety: Application to the Synthesis of 7-Norbornanone Derivatives.

We describe a method for the synthesis of various 2-silyloxy-2-norbornen-7-ones by exploiting the specific reactivity of the 1,4-bis(silyloxy)-1,3-cyclopentadiene framework, which is generated by the silylation of a 2,2-disubstituted-1,3-cyclopentanedione bearing a picolinoyloxy group at the 2' position of its C-2 side chain. The release of the acyloxy group during the reaction generates carbocations that are then attacked by silyloxy-substituted carbons in the 1,4-bis(silyloxy)-1,3-cyclopentadiene moiety skeleton, forming a 4,5-cis-fused ring skeleton. Skeletal rearrangement of the bicyclic core results in the formation of the corresponding 2-silyloxy-2-norbornen-7-one. This novel transformation of 1,3-cyclopentanedione moieties can be used to synthesise other cyclopentenone-fused bicyclic frameworks.

Thickness-controllable synthesis of metal-organic framework based hollow nanoflowers with magnetic core via liquid phase epitaxy for phosphopeptides enrichment

Thickness-controllable synthesis of metal-organic framework based hollow nanoflowers with magnetic core via liquid phase epitaxy for phosphopeptides enrichment

Extended π-conjugated systems by external ligand-assisted C−H olefination of heterocycles: Facile access to single-molecular white-light-emitting and NIR fluorescence materials

The design and synthesis of a novel π-conjugated fluorescent framework by external ligand-assisted C−H olefination of heterocycles with excellent regioselectivity and broad substrate scope are reported herein. These novel fluorescent materials could present full-color-tunable emissions with large Stokes shifts. Furthermore, the protocol provides an opportunity to rapidly screen novel organic single-molecule white-light materials with high fluorescence quantum yields. The robust organic and low-cost white light-emitting diodes could rapidly be fabricated using the white-light-emitting material. Experimental data and theoretical calculations indicate that in the white-light dual emission the relatively short wavelength from high-lying singlet state emission and the relatively long wavelength from low-lying singlet state emission. The anti-Kasha dual-emission systems will provide a foundation for the development and application of organic single-molecule white light materials, effectively promoting the development and innovation of luminescent materials. In addition, this method demonstrated its potential application in the synthesis of new near-infrared (NIR) fluorescence materials with large Stokes shifts based on the olefination of heterocycles.

Isolated Pulsar Population Synthesis with Simulation-based Inference

We combine pulsar population synthesis with simulation-based inference (SBI) to constrain the magnetorotational properties of isolated Galactic radio pulsars. We first develop a framework to model neutron star birth properties and their dynamical and magnetorotational evolution. We specifically sample initial magnetic field strengths, B, and spin periods, P, from lognormal distributions and capture the late-time magnetic field decay with a power law. Each lognormal is described by a mean, μlogB,μlogP , and standard deviation, σlogB,σlogP , while the power law is characterized by the index, a late. We subsequently model the stars’ radio emission and observational biases to mimic detections with three radio surveys, and we produce a large database of synthetic P– Ṗ diagrams by varying our five magnetorotational input parameters. We then follow an SBI approach that focuses on neural posterior estimation and train deep neural networks to infer the parameters’ posterior distributions. After successfully validating these individual neural density estimators on simulated data, we use an ensemble of networks to infer the posterior distributions for the observed pulsar population. We obtain μlogB=13.10−0.10+0.08 , σlogB=0.45−0.05+0.05 and μlogP=−1.00−0.21+0.26 , σlogP=0.38−0.18+0.33 for the lognormal distributions and alate=−1.80−0.61+0.65 for the power law at the 95% credible interval. We contrast our results with previous studies and highlight uncertainties of the inferred a late value. Our approach represents a crucial step toward robust statistical inference for complex population synthesis frameworks and forms the basis for future multiwavelength analyses of Galactic pulsars.

Advisory groups in realist reviews: Systematically mapping current research and recommendations for practice

AbstractIntroductionRealist reviews may involve groups or panels external to the research team who provide external and independent perspectives informing the review based on their experience of the topic area. These panels or groups are termed in this study as an “advisory group.” This study aims to map current practice of advisory groups in realist reviews and provide guidance for planning and reporting.MethodsA “best‐fit” framework synthesis methodology was used by first searching for a best‐fit framework and then conducting a systematic search to identify a sample of realist reviews and rapid realist reviews (RRRs) from the most recent year, 2021. Nine databases were searched: CINAHL Complete, Cochrane, Embase, ERIC, MEDLINE, PsycInfo, Social Services Abstracts, Sociological Abstracts, and Web of Science Core Collection. Screening and data extraction was conducted by two researchers. The chosen best‐fit framework (ACTIVE framework) informed the data extraction tool.ResultsOne hundred and seven reviews (93 realist reviews, 14 RRRs) were identified for inclusion. Of these, 40% (n = 37) of realist reviews and 71.5% (n = 10) of RRRs mentioned use of an advisory group, though there was considerable variation in terminology used. Individuals in advisory groups were involved at varying stages of the review and tended to bring experience in the topic area from the perspective of (i) a lived experience, i.e., patients, carers, family members (n = 15 realist reviews; n = 4 RRRs); (ii) professional experience, such as healthcare professionals (n = 20 realist reviews; n = 6 RRRs); or (iii) policy or research experience in the topic area (n = 19 realist reviews; n = 7 RRRs).ConclusionsThis study proposes a definition of advisory groups, considerations for advisory group use, and suggested items for reporting. The purpose of the advisory group should be carefully considered when deciding on their use in a realist review.

Generalized Model for Inhibitor-Modulated 2D Polymer Growth to Understand the Controlled Synthesis of Covalent Organic Frameworks.

Two-dimensional (2D) polymers, also known as 2D covalent organic frameworks (COFs), are increasingly finding use in applications such as membrane separations, catalysis, and energy conversion. Current research is focused on the development of new synthesis routes for COFs and obtaining a mechanistic understanding of the growth process to control it in a better manner. In this regard, synthesis methods such as reversible polycondensation termination use monofunctional inhibitor species to achieve a controlled growth rate for COFs. However, so far, the role of the inhibitors in modulating the kinetics of COF growth is inadequately understood. In this work, inspired by the Mayo-Lewis framework, we develop a generalized kinetic model to describe the synthesis of a 2D COF monolayer. Our model involves six parameters corresponding to the rate constants of attachment and detachment of monomer and inhibitor species, as well as enhancement factors that quantify the effect of the local coordination environment of the attaching/detaching species on the reaction kinetics. We measure the inhibitor concentration-dependent growth kinetics of the COF experimentally and fit our model to experimental yield data, with the same parameters working across multiple inhibitor concentrations. As the growth process is inherently stochastic, we use this knowledge to develop a comprehensive kinetic Monte Carlo (KMC) simulation of 2D COF synthesis, demonstrating that scaled rate constants are required in the inherently local KMC simulations rather than those obtained from the global kinetic model. The KMC simulations point to an inverse flake size-inhibitor concentration relationship, in agreement with experiments, indicating that flake sizes could be precisely regulated by changing the inhibitor concentrations. Overall, our work promises to improve the understanding of 2D COF synthesis and will help in controlling the growth process to obtain the desired flake size distribution and product morphology.

Sustainable Development of Platform Enterprises: A Synthesis Framework

Enterprises are the most important core organizations of the country and modern society, and their growth has always been a focal point in the theoretical field. This paper aims to focus on the sustainable development of platform enterprises by exploring the mechanism of platform growth. Thus, this paper reviews the literature and analyzes the challenges faced by platform enterprises during the four stages of birth, expansion, leadership, and self-renewal, as well as the strategies they have adopted. The main aims of this paper are to help understand the growth process of platform enterprises and identify three key points that need to be addressed for sustainable growth, including the disadvantages of resource externalities, the importance of the restructuration of business models, and the urgency of fulfilling social responsibility. To address the exogenous nature of resources, platform enterprises should pay attention to the initiative of complementors, the distribution of benefits, and ecological orchestration. The impact of technology, especially artificial intelligence, on business models and the application of technology to restructure business models should be given attention. It is also necessary to pay attention to how platform enterprises undertake their social responsibilities. A synthesis framework with seven propositions for future research has been proposed.

Language as a tool for intercultural understanding: Multilingual approaches in global citizenship education

The paper explores the pivotal role of language as a catalyst for fostering intercultural understanding within the framework of multilingual approaches in global citizenship education. In an increasingly interconnected world, language is a dynamic tool for bridging cultural divides and nurturing empathy, respect, and appreciation for diverse perspectives. Multilingualism, embraced within educational contexts, becomes instrumental in shaping informed global citizens equipped with the skills and mindset to navigate the complexities of our interconnected world. This paper delves into the theoretical underpinnings of multilingual education and its implications for global citizenship, emphasizing the transformative potential of linguistic diversity. By incorporating diverse linguistic and cultural perspectives into curricula, educators can cultivate a sense of curiosity and open-mindedness among students, facilitating meaningful intercultural dialogue and collaboration. Furthermore, the paper highlights the emerging trends in multilingual education, such as translanguaging pedagogy and content and language-integrated learning (CLIL), as practical approaches to promote language proficiency and intercultural competence. These strategies empower students to leverage their multilingual learning, communication, and problem-solving skills, fostering a deeper understanding of global issues and promoting social justice and sustainability. Through a synthesis of theoretical frameworks, empirical research, and practical insights, this paper seeks to contribute to the ongoing discourse on the role of language in promoting intercultural understanding and global citizenship. By recognizing language as a powerful tool for building bridges across cultures and fostering inclusive societies, educators and policymakers can work towards creating more equitable and interconnected communities where linguistic diversity is celebrated and valued. In addition to exploring the theoretical foundations and practical applications of multilingual approaches in global citizenship education, this study delves into the importance of policy frameworks and institutional support in fostering linguistic diversity within educational settings. Effective language-in-education policies that recognize and promote the linguistic rights of all learners are essential for creating inclusive learning environments where students feel valued and empowered to express themselves in their mother tongue. Furthermore, the paper discusses the need for professional development opportunities for educators to enhance their pedagogical practices and intercultural competence in multilingual settings.