Metal-Organic Frameworks

金属 - 有机框架
  • 文章类型: Journal Article
    金属有机骨架(MOFs)是在气体吸附和分离等领域具有潜在应用的材料,催化作用,和生物医学。增强MOFs效用的尝试涉及各种复合材料的制备,包括聚合物接枝的MOFs。通过将聚合物直接接枝到MOFs的外表面,可以克服聚合物和MOF之间的不相容问题。从MOF的表面接枝的聚合物刷可以用于稳定MOF,同时能够通过聚合物-聚合物相互作用将颗粒组装成自组装的金属-有机骨架单层(SAMM)。对接枝聚合物的化学组成和分子量的控制可以允许调节SAMM特性。在这项工作中,提供了关于如何将链转移剂(CTA)固定到MOFUiO-66(UiO=奥斯陆大学)表面上的说明。CTA用作聚合物生长的起始位点。一旦聚合物链从MOF表面生长,SAMM的形成是通过在空气-水界面处的自组装来实现的。通过扫描电子显微镜成像对所得SAMM进行表征并显示为独立的。本文提出的方法有望使SAMM的制备更容易为研究界所用,从而扩大其作为MOF-聚合物复合材料的潜在用途。
    Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. Attempts to enhance the utility of MOFs have involved the preparation of various composites, including polymer-grafted MOFs. By directly grafting polymers to the external surface of MOFs, issues of incompatibility between polymers and MOFs can be overcome. Polymer brushes grafted from the surface of MOFs can serve to stabilize the MOF while enabling particle assembly into self-assembled metal-organic framework monolayers (SAMMs) via polymer-polymer interactions. Control over the chemical composition and molecular weight of the grafted polymer can allow for tuning of the SAMM characteristics. In this work, instructions are provided on how to immobilize a chain transfer agent (CTA) onto the surface of the MOF UiO-66 (UiO = Universitetet i Oslo). The CTA serves as initiation sites for the growth of polymers. Once polymer chains are grown from the MOF surface, the formation of SAMMs is achieved through self-assembly at an air-water interface. The resulting SAMMs are characterized and shown to be freestanding by scanning electron microscopy imaging. The methods presented in this paper are expected to make the preparation of SAMMs more accessible to the research community and thereby expand their potential use as a MOF-polymer composite.
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  • 文章类型: Journal Article
    组织中的基因分型和淀粉样原纤维检测通常被认为是甲状腺素运载蛋白相关淀粉样变性的诊断金标准。患者携带不太稳定的TTR同源四聚体,容易解离成非天然单体,快速自组装成低聚物,最终,淀粉样纤维.因此,淀粉样蛋白级联的初始事件产生最小的转甲状腺素蛋白种类:单体。这创造了仍未探索的诊断工程机会。
    我们假设分子筛代表了一种有前途的方法,用于从血浆样品中存在的四聚体中分离和浓缩痕量TTR单体。随后,免疫检测可用于将单体TTR与吸附部分内的其他低分子量蛋白质区分开。设计了两步法(免疫测定法),结合分子筛分和免疫检测来感知单体转甲状腺素蛋白。该测定法用于分析来自10个人的血浆微样品,包括5名症状前的TTR-V30M携带者,全球最普遍的淀粉样变性相关TTR变异,5健康对照
    Immunosive分析能够灵敏地检测血浆微样品中的单体转甲状腺素蛋白。此外,在淀粉样变性TTR突变的携带者中,循环单体TTR水平显著较高.
    单体TTR可以作为生物标志物用于评估疾病进展和评估对靶向稳定天然TTR的治疗的反应。
    UNASSIGNED: Genotyping and amyloid fibril detection in tissues are generally considered the diagnostic gold standard in transthyretin-related amyloidosis. Patients carry less stable TTR homotetramers prone to dissociation into non-native monomers, which rapidly self-assemble into oligomers and, ultimately, amyloid fibrils. Thus, the initial event of the amyloid cascade produces the smallest transthyretin species: the monomers. This creates engineering opportunities for diagnosis that remain unexplored.
    UNASSIGNED: We hypothesise that molecular sieving represents a promising method for isolating and concentrating trace TTR monomers from the tetramers present in plasma samples. Subsequently, immunodetection can be utilised to distinguish monomeric TTR from other low molecular weight proteins within the adsorbed fraction. A two-step assay was devised (ImmunoSieve assay), combining molecular sieving and immunodetection for sensing monomeric transthyretin. This assay was employed to analyse plasma microsamples from 10 individuals, including 5 pre-symptomatic carriers of TTR-V30M, the most prevalent amyloidosis-associated TTR variant worldwide, and 5 healthy controls.
    UNASSIGNED: The ImmunoSieve assay enable sensitive detection of monomeric transthyretin in plasma microsamples. Moreover, the circulating monomeric TTR levels were significantly higher in carriers of amyloidogenic TTR mutation.
    UNASSIGNED: Monomeric TTR can function as a biomarker for evaluating disease progression and assessing responses to therapies targeted at stabilising native TTR.
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  • 文章类型: Journal Article
    重金属离子和抗生素污染已成为世界范围内的主要环境问题。在水溶液中超低浓度的这些污染物的有效识别策略的开发以及内在传感机制的阐明是具有挑战性的任务。在这项工作中,通过合理的配体设计组装了独特的发光Ln-MOF材料(NIIC-3-Ln)。其中,NIIC-3-Tb在小于7s的亚纳摩尔浓度下表现出对Hg2和磺胺嘧啶(SDI)的高度选择性发光猝灭响应。此外,在单晶X射线衍射分析和Hg2+吸附研究的基础上,提出了一种通过螯合的Hg2+传感机理。使用新开发的方法揭示了NIIC-3-Tb与SDI的相互作用机理,该方法涉及基于(TD-)DFT的MOF分析物超分子复合物模型在基态和激发态下的电荷转移定量。通过气体吸附实验揭示了超声处理对MOF传感性能重要的表面形态的影响。结果表明,NIIC-3-Ln不仅是在超低浓度下有效检测Hg2和SDI的先进传感材料,同时也为在超低浓度下研究分子水平的传感机理开辟了新的途径。
    Heavy metal ions and antibiotic contamination have become a major environmental concern worldwide. The development of efficient recognition strategies of these pollutants at ultra-low concentrations in aqueous solutions as well as the elucidation of the intrinsic sensing mechanism are challenging tasks. In this work, unique luminescent Ln-MOF materials (NIIC-3-Ln) were assembled by rational ligand design. Among them, NIIC-3-Tb demonstrated highly selective luminescence quenching response toward Hg2+ and sulfadiazine (SDI) at subnanomolar concentrations in less than 7 s. In addition, a Hg2+ sensing mechanism through chelation was proposed on the basis of single-crystal X-ray diffraction analysis and Hg2+ adsorption study. The interaction mechanism of NIIC-3-Tb with SDI was revealed using a newly developed approach involving a (TD-)DFT based quantification of the charge transfer of a MOF-analyte supramolecular complex model in the ground and excited states. Effect of ultrasonic treatment on the surface morphology important for MOF sensing performance was revealed by gas adsorption experiments. The presented results indicate that NIIC-3-Ln is not only an advanced sensing material for the efficient detection of Hg2+ and SDI at ultra-low concentrations, but also opens up a new approach to study the sensing mechanism at the molecular level at ultra-low concentrations.
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  • 文章类型: Journal Article
    这项工作研究了应用顶空固相微萃取-气相色谱-质谱(HS-SPME-GC/MS)结合嗅觉可视化表征黑蒜风味的可行性。进行挥发性有机化合物(VOCs)分析以选择黑蒜加工过程中重要的差异VOCs。然后开发了与两个多孔金属有机框架组装的多通道纳米复合材料CSA,以表征黑蒜加工过程中的风味变化,大蒜样品在加工过程中可以分为五组,与VOCs分析一致。人工神经网络(ANN)模型在区分处理阶段优于其他模式识别方法。此外,气味感官评分的SVR模型的预测相关系数为0.8919,表现出比PLS模型更好的性能。表明对气味质量有较好的预测能力。这项工作表明,结合适当的化学计量学的纳米复合材料CSA可以为客观,快速地表征黑蒜或其他食品基质的风味质量提供有效的工具。
    This work investigated the feasibility of applying headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS) combining olfactory visualization for flavor characterization of black garlic. Volatile organic compounds (VOCs) analysis was performed to select important differential VOCs during black garlic processing. A multi-channels nanocomposite CSA assembled with two porous metal-organic frameworks was then developed to characterize flavor profiles changes during black garlic processing, and garlic samples during processing could be divided into five clusters, consistent with VOCs analysis. Artificial neural network (ANN) model outperformed other pattern recognition methods in discriminating processing stages. Furthermore, SVR model for odor sensory scores with the correlation coefficient for prediction set of 0.8919 exhibited a better performance than PLS model, indicating a preferable prediction ability for odor quality. This work demonstrated that the nanocomposite CSA combining appropriate chemometrics can offer an effective tool for objectively and rapidly characterizing flavor quality of black garlic or other food matrixes.
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  • 文章类型: Journal Article
    次磷酸铝(AHP)作为阻燃剂已经使用了很长时间。以往关于AHP在阻燃材料中应用的研究主要集中在涂层,修改,复杂的系统。探索用AHP和金属有机骨架(MOFs)制备纳米杂化物的简单实验步骤是有价值的。我们发现酸性物质可以蚀刻沸石咪唑酯骨架67(ZIF-67)以获得MOF衍生物。不幸的是,AHP和ZIF-67不能直接形成杂交体。因此,羧甲基纤维素(CMC)作为双功能层(缓冲层和载体)引入。CMC抵抗由磷酸蚀刻的ZIF-67完全转化为无定形磷酸钴水合物(ACP)。同时,含有羟基的CMC通过静电相互作用和配位键与AHP结合。通过这种一石双鸟策略合成了双层空心MOF衍生物。由于多种阻燃元素和独特的纳米结构,这种MOF衍生物赋予环氧(EP)树脂优异的阻燃性。添加2.0wt%时,EP/AHP/ACP@CMC的峰值放热率(pHRR)和总放热(THR)分别降低了47.8和21.0%,分别。本研究提出了一种将AHP转化为MOF衍生物作为高性能FR的新方案。
    Aluminum hypophosphite (AHP) has been used as a flame retardant for a long time. Previous studies about AHP employed in flame retardant materials mostly focus on coating, modification, and complex system. It is valuable to explore simple experimental steps to prepare nano hybrids with AHP and metal-organic frameworks (MOFs). We found acidic substances could etch zeolitic imidazolate framework-67 (ZIF-67) to obtain MOF derivatives. Unfortunately, AHP and ZIF-67 could not directly form a hybrid. Therefore, carboxymethylcellulose (CMC) is introduced as a dual function layer (buffer and support). The CMC resists the complete conversion of ZIF-67 etched by phosphoric acid to amorphous cobalt phosphate hydrate (ACP). Meanwhile, CMC containing hydroxyl groups combines with AHP through electrostatic interaction and coordination bonds. A double-layer hollow MOF derivative is synthesized through this one-stone-two-birds strategy. Due to multiple flame retardant elements and unique nanostructure, this MOF derivative endows epoxy (EP) resin with excellent flame retardancy. With 2.0 wt% addition, the peak heat release rate (pHRR) and total heat release (THR) of EP/AHP/ACP@CMC are decreased by 47.8 and 21.0 %, respectively. This study proposes a novel scheme that converts AHP into MOF derivatives as high-performance FRs.
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  • 文章类型: Journal Article
    结合了二维(2D)无机纳米片的物理优势以及金属有机框架(MOFs)的模块化设计和编程结构,2DMOFs仍然处于功能材料研究的前沿。尽管付出了巨大的努力,在2D非分层MOFs的合成与所需应用的预先设计的拓扑的精确控制仍然具有挑战性。通过配体交换成功地自下而上地合成2D非层状MOF,促使我们将部分BTC(BTC=1,3,5-苯三羧酸酯)配体解离和CO2封端的配位纳入块状Cu-BTCMOF的自上而下处理中,导致3D非分层网络成功转换为2D基于Cu的拓扑结构。值得注意的是,使用超临界含CO2的溶剂混合物来提供所需的缺陷和协调工程。因此,我们的工作引入了一种基于调制合成的自上而下的新概念,以首次制造高质量的2D非分层MOFs。
    Combining the physical advantages of two-dimensional (2D) inorganic nanosheets and the modular design and programmed structure of metal-organic frameworks (MOFs), 2D MOFs remain at the forefront of functional material research. Despite tremendous efforts, precise control in the synthesis of 2D nonlayered MOFs with predesigned topology for desired applications remains challenging. Success in the bottom-up synthesis of 2D nonlayered MOFs via ligand exchange motivated us to incorporate partial BTC (BTC = 1,3,5-benzenetricarboxylate) ligand dissociation and CO2 capped coordination into the top-down treatment of bulk Cu-BTC MOF, leading to successful conversion of a 3D nonlayered network to a 2D Cu-based topological structure. Notably, a supercritical CO2-containing solvent mixture is employed to provide the desired defect and coordination engineering. Thus, our work introduces a new top-down concept based on modulated synthesis to fabricate high-quality 2D nonlayered MOFs for the first time.
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  • 文章类型: Journal Article
    2,6-吡啶二羧酸(DPA)是臭名昭著的炭疽孢子的特殊生物标志物。因此,快速,敏感,选择性定量检测DPA具有极其重要的意义和紧迫性。本文报道了式为{[Zn6(NDA)6(DPBT)3]2H2O·3DMF}n(MOF-1)的Zn(II)金属有机骨架,由2,6-萘二羧酸(2,6-NDA)组成,4,7-二(4-吡啶基)-2,1,3-苯并噻二唑(DPBT),和Zn(II)离子。结构分析表明,MOF-1是在单斜晶系中结晶的三维(3D)网络,具有C2/c空间群,显示高pH值,溶剂,和热稳定性。发光传感研究表明,MOF-1具有高选择性,敏感,和可回收荧光传感器用于识别DPA。此外,制作荧光试纸,以快速检测颜色变化的DPA。通过MOF-1和DPA分子之间的氢键相互作用和光诱导电子转移跃迁建立了增强机制。
    2,6-pyridine dicarboxylic acid (DPA) is an exceptional biomarker of notorious anthrax spores. Therefore, the rapid, sensitive, and selective quantitative detection of DPA is extremely significant and urgent. This paper reports a Zn(II) metal-organic framework with the formula of {[Zn6(NDA)6(DPBT)3] 2H2O·3DMF}n (MOF-1), which consists of 2,6-naphthalenedicarboxylic acid (2,6-NDA), 4,7-di(4-pyridyl)-2,1,3-benzothiadiazole (DPBT), and Zn(II) ions. Structural analysis indicated that MOF-1 is a three-dimensional (3D) network which crystallized in the monoclinic system with the C2/c space group, revealing high pH, solvent, and thermal stability. Luminescence sensing studies demonstrated that MOF-1 had the potential to be a highly selective, sensitive, and recyclable fluorescence sensor for the identification of DPA. Furthermore, fluorescent test paper was made to detect DPA promptly with color changes. The enhancement mechanism was established by the hydrogen-bonding interaction and photoinduced electron transfer transition between MOF-1 and DPA molecules.
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  • 文章类型: Journal Article
    从N2中有效分离CH4对于从氮气中纯化甲烷是必不可少的。为了解决这个问题,合成了由棒状SBA-15基UiO-66-Br2组成的复合材料,用于分离CH4/N2混合物。通过PXRD对材料进行了表征,N2吸附-解吸,SEM,TEM,FT-IR,和TGA。确定了CH4和N2在标准压力条件下对复合材料的吸附等温线,然后进行了比较。研究表明,复合材料是通过MOF纳米晶体在SBA-15基体表面的生长形成的。杂化材料的表面积和吸附能力的增强归因于表面硅烷醇基团与金属中心之间的相互作用引起的结构修饰。利用Langmuir吸附方程评估了复合材料对CH4和N2气体混合物的选择性。分析结果表明,与其他样品相比,U6B2S5/SBA-15样品对CH4/N2吸附的选择性最大,吸附选择性参数(S)为20.06。需要进行其他研究,以使用SBA-15基金属有机骨架材料增强CH4/N2混合物中甲烷的富集。
    Efficient separation of CH4 from N2 is essential for the purification of methane from nitrogen. In order to address this problem, composite materials consisting of rod-shaped SBA-15-based UiO-66-Br2 were synthesized for the purpose of separating a CH4/N2 mixture. The materials were characterized via PXRD, N2 adsorption-desorption, SEM, TEM, FT-IR, and TGA. The adsorption isotherms of CH4 and N2 under standard pressure conditions for the composites were determined and subsequently compared. The study revealed that the composites were formed through the growth of MOF nanocrystals on the surfaces of the SBA-15 matrix. The enhancements in surface area and adsorption capacity of hybrid materials were attributed to the structural modifications resulting from the interactions between surface silanol groups and metal centers. The selectivity of the composites towards a gas mixture of CH4 and N2 was assessed utilizing the Langmuir adsorption equation. The results of the analysis revealed that the U6B2S5/SBA-15 sample exhibited the greatest selectivity for CH4/N2 adsorption compared to the other samples, with an adsorption selectivity parameter (S) of 20.06. Additional research is necessary to enhance the enrichment of methane from CH4/N2 mixtures using SBA-15-based metal-organic framework materials.
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  • 文章类型: Journal Article
    醛在温和条件下的氧化酯化仍然是一个重大挑战。这项研究引入了一种独特的缺陷UiO-66,以实现在温和条件下有效的醛氧化的金纳米簇(AuNC)。通过XRD技术对这些材料的结构和表征进行了深入的研究,SEM和TEM图像,FT-IR,拉曼,和XPS光谱,强调缺陷型UiO-66中独特的微孔有利于AuNC的制造。系统地评价了所制备材料在醛氧化反应中的催化性能,证明了分散的Au@UiO-66-25具有高含量(9.09wt%)Au负载和超小尺寸(〜2.7nm)的显着效率。此外,提供了在温和条件下(70°C持续1小时)对催化过程的机械见解,阐明在AuNC的有限制造和随后的糠醛吸附中确定有缺陷的UiO-66,这是管理观察到的增强功能的原则的基础。这项研究为使用有缺陷的MOFs作为平台合成高度分散和催化活性的金属纳米颗粒奠定了基础,将糠醛催化酯化反应提高到一个新的水平。
    The oxidative esterification of aldehydes under mild conditions remains a significant challenge. This study introduces a unique defective UiO-66 to achieve gold nanoclusters (AuNCs) for efficient aldehyde oxidation under mild conditions. The construction and characterization of these materials are thoroughly investigated by techniques of XRD, SEM and TEM images, FT-IR, Raman, and XPS spectrum, emphasizing the unique microporous in defective UiO-66 are conducive to the fabrication of AuNCs. The catalytic performance of the prepared materials in aldehyde oxidation reactions is systematically evaluated, demonstrating the remarkable efficiency of dispersed Au@UiO-66-25 with high-content (9.09 wt%) Au-loading and ultra-small size (~2.7 nm). Moreover, mechanistic insights into the catalytic process under mild conditions (70 °C for 1 h) are provided, elucidating the determination of defective UiO-66 in the confined fabrication of AuNCs and subsequent furfural adsorption, which underlie the principles governing the observed enhancements. This study establishes the groundwork for the synthesis of highly dispersed and catalytically active metal nanoparticles using defective MOFs as a platform, advancing the catalytic esterification reaction of furfural to the next level.
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  • 文章类型: Journal Article
    在环境化学中,用于消除水中有机污染物的光催化剂已经获得了极大的兴趣。我们的研究引入了结合MIL-101(Cr)和碘化铋(Bi5O7I)的独特异质结构。我们评估了这种纳米结构在可见光下吸附和降解四环素(TC)的效率。Bi5O7I@MIL-101(Cr)复合材料,表面积为637m2/g,防止在其组件中看到的自聚集,增强可见光的吸收。其光催化效率分别超过Bi5O7I和MIL-101(Cr)的33.4和9.2倍,分别。综合分析,包括扫描电子显微镜(SEM)和透射电子显微镜(TEM),证实了具有明确形态特征的异质结构的成功形成。BET分析表明其高表面积,而X射线衍射(XRD)证实了其结晶度。电子自旋共振(ESR)测试表明,在光下会产生大量的活性氧(ROS),例如h和··O2-。对TC降解至关重要。该材料在五个周期内保持了优异的耐久性。密度泛函理论(DFT)模拟和经验研究揭示了Bi5O7I和MIL-101(Cr)之间的I型异质结,促进有效的电子-空穴对分离。这项研究强调了Bi5O7I@MIL-101(Cr)的优异光催化活性和稳定性,提供对设计用于水净化的创新光催化剂的见解。
    In environmental chemistry, photocatalysts for eliminating organic contaminants in water have gained significant interest. Our study introduces a unique heterostructure combining MIL-101(Cr) and bismuth oxyiodide (Bi5O7I). We evaluated this nanostructure\'s efficiency in adsorbing and degrading tetracycline (TC) under visible light. The Bi5O7I@MIL-101(Cr) composite, with a surface area of 637 m2/g, prevents self-aggregation seen in its components, enhancing visible light absorption. Its photocatalytic efficiency surpassed Bi5O7I and MIL-101(Cr) by 33.4 and 9.2 times, respectively. Comprehensive analyses, including scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirmed the successful formation of the heterostructure with defined morphological characteristics. BET analysis demonstrated its high surface area, while X-ray diffraction (XRD) confirmed its crystallinity. Electron spin resonance (ESR) tests showed significant generation of reactive oxygen species (ROS) like h+ and·•O2- under light, crucial for TC degradation. The material maintained exceptional durability over five cycles. Density functional theory (DFT) simulations and empirical investigations revealed a type I heterojunction between Bi5O7I and MIL-101(Cr), facilitating efficient electron-hole pair separation. This study underscores the superior photocatalytic activity and stability of Bi5O7I@MIL-101(Cr), offering insights into designing innovative photocatalysts for water purification.
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