共查询到20条相似文献,搜索用时 578 毫秒
1.
Dr. Jun Liang Alexander Nuhnen Simon Millan Hergen Breitzke Vasily Gvilava Dr. Gerd Buntkowsky Prof. Dr. Christoph Janiak 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6124-6129
We present a facile approach to encapsulate functional porous organic cages (POCs) into a robust MOF by an incipient-wetness impregnation method. Porous cucurbit[6]uril (CB6) cages with high CO2 affinity were successfully encapsulated into the nanospace of Cr-based MIL-101 while retaining the crystal framework, morphology, and high stability of MIL-101. The encapsulated CB6 amount is controllable. Importantly, as the CB6 molecule with intrinsic micropores is smaller than the inner mesopores of MIL-101, more affinity sites for CO2 are created in the resulting CB6@MIL-101 composites, leading to enhanced CO2 uptake capacity and CO2/N2, CO2/CH4 separation performance at low pressures. This POC@MOF encapsulation strategy provides a facile route to introduce functional POCs into stable MOFs for various potential applications. 相似文献
2.
Jurjen Spekreijse Prof. Lars Öhrström Prof. Johan P. M. Sanders Prof. Johannes H. Bitter Dr. Elinor L. Scott 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15437-15443
A simple, one‐step mechanochemical procedure for immobilisation of homogeneous metathesis catalysts in metal–organic frameworks was developed. Grinding MIL‐101‐NH2(Al) with a Hoveyda–Grubbs second‐generation catalyst resulted in a heterogeneous catalyst that is active for metathesis and one of the most stable immobilised metathesis catalysts. During the mechanochemical immobilisation the MIL‐101‐NH2(Al) structure was partially converted to MIL‐53‐NH2(Al). The Hoveyda–Grubbs catalyst entrapped in MIL‐101‐NH2(Al) is responsible for the observed catalytic activity. The developed synthetic procedure was also successful for the immobilisation of a Zhan catalyst. 相似文献
3.
Dr. Sanil E. Sivan Minhui Lee Su-Kyung Lee Dr. Ji Woong Yoon Dr. Kiwoong Kim Dr. Do-Young Hong Kyung-Ho Cho Dr. U-Hwang Lee Prof. Jong-San Chang Dr. Jaehoon Jung Prof. Young Kyu Hwang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12889-12894
Oxo-bridged trimeric chromium acetate clusters [Cr3O(OOCCH3)6(H2O)3]NO3 have been encapsulated for the first time in the mesoporous cages of the chromium terephthalate MIL-101(Cr). The isolated clusters in MIL-101(Cr) have increased affinity towards propylene compared to propane, due to generation of a new kind of pocket-based propylene-binding site, as supported by DFT calculations. 相似文献
4.
Zhongshang Dou Jianfeng Cai Yuanjing Cui Jiancan Yu Tifeng Xia Yu Yang Guodong Qian 《无机化学与普通化学杂志》2015,641(5):792-796
Continuous and intergrown metal‐organic framework (MOF) membranes, MIL‐100(In) (MIL represents Materials Institute Lavoisier), were prepared directly on porous anodic alumina oxide (AAO) membranes using an in situ crystallization method. The pore surface of MIL‐100(In) is conferred with polarity due to the presence of the 1, 3,5‐benzenetricarboxylic acid. The thickness of MIL‐100(In) membranes was tuned by varying the reactant concentration of indium chloride and 1, 3,5‐benzenetricarboxylic acid. Single gas permeation measurements on this MOF membrane indicate the large permeances of 0.90 × 10–6 and 0.81 × 10–6 mol · m–2·s–1·Pa–1 for CO2 and CH4, and relatively high ideal selective factors of 3.75 and 3.38 for CO2/N2 and CH4/N2, respectively. 相似文献
5.
Five different imidazolium‐based ionic liquids (ILs) were incorporated into a metal–organic framework (MOF), MIL‐53(Al), to investigate the effect of IL incorporation on the CO2 separation performance of MIL‐53(Al). CO2, CH4, and N2 adsorption isotherms of the IL/MIL‐53(Al) composites and pristine MIL‐53(Al) were measured to evaluate the effect of the ILs on the CO2/CH4 and CO2/N2 selectivities of the MOF. Of the composite materials that were tested, [BMIM][PF6]/MIL‐53(Al) exhibited the largest increase in CO2/CH4 selectivity, 2.8‐times higher than that of pristine MIL‐53(Al), whilst [BMIM][MeSO4]/MIL‐53(Al) exhibited the largest increase in CO2/N2 selectivity, 3.3‐times higher than that of pristine MIL‐53(Al). A comparison of the CO2 separation potentials of the IL/MOF composites showed that the [BMIM][BF4]‐ and [BMIM][PF6]‐incorporated MIL‐53(Al) composites both showed enhanced CO2/N2 and CO2/CH4 selectivities at pressures of 1–5 bar compared to composites of CuBTC and ZIF‐8 with the same ILs. These results demonstrate that MIL‐53(Al) is a versatile platform for IL/MOF composites and could help to guide the rational design of new composites for target gas‐separation applications. 相似文献
6.
Diego Mateo Andrea Santiago‐Portillo Josep Albero Sergio Navaln Mercedes Alvaro Hermenegildo García 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(49):18007-18012
Prolonged (weeks) UV/Vis irradiation under Ar of UiO‐66(Zr), UiO66 Zr‐NO2, MIL101 Fe, MIL125 Ti‐NH2, MIL101 Cr and MIL101 Cr(Pt) shows that these MOFs undergo photodecarboxylation of benzenedicarboxylate (BDC) linker in a significant percentage depending on the structure and composition of the material. Routine characterization techniques such as XRD, UV/Vis spectroscopy and TGA fail to detect changes in the material, although porosity and surface area change upon irradiation of powders. In contrast to BCD‐containing MOFs, zeolitic imidazolate ZIF‐8 does not evolve CO2 or any other gas upon irradiation. 相似文献
7.
《Journal of separation science》2018,41(5):1129-1137
We adopted a facile hydrofluoric acid‐free hydro‐/solvothermal method for the preparation of four magnetic iron(III)‐based framework composites (MIL‐101@Fe3O4‐COOH, MIL‐101‐NH2@Fe3O4‐COOH, MIL‐53@Fe3O4‐COOH, and MIL‐53‐NH2@Fe3O4‐COOH). The obtained four magnetic iron(III)‐based framework composites were applied to magnetic separation and enrichment of the fungicides (prochloraz, myclobutanil, tebuconazole, and iprodione) from environmental samples before high‐performance liquid chromatographic analysis. MIL‐101‐NH2@Fe3O4‐COOH showed more remarkable pre‐concentration ability for the fungicides as compared to the other three magnetic iron(III)‐based framework composites. The extraction parameters affecting enrichment efficiency including extraction time, sample pH, elution time, and the desorption solvent were investigated and optimized. Under the optimized conditions, the standard curve of correlation coefficients were all above 0.991, the limits of detection were 0.04–0.4 μg/L, and the relative standard deviations were below 10.2%. The recoveries of two real water samples ranged from 71.1–99.1% at the low spiking level (30 μg/L). Therefore, the MIL‐101‐NH2@Fe3O4‐COOH composites are attractive for the rapid and efficient extraction of fungicides from environmental water samples. 相似文献
8.
An Efficient Nanoscale Heterogeneous Catalyst for the Capture and Conversion of Carbon Dioxide at Ambient Pressure 下载免费PDF全文
Xiao‐Huan Liu Dr. Jian‐Gong Ma Dr. Zheng Niu Prof. Dr. Guang‐Ming Yang Prof. Dr. Peng Cheng 《Angewandte Chemie (International ed. in English)》2015,54(3):988-991
Silver nanoparticles were successfully supported on the zeolite‐type metal–organic framework MIL‐101 to yield Ag@MIL‐101 by a simple liquid impregnation method. For the first time, the conversion of terminal alkynes into propiolic acids with CO2 was achieved by the use of the Ag@MIL‐101 catalysts. Owing to the excellent catalytic activity, the reaction proceeded at atmospheric pressure and low temperature (50 °C). The Ag@MIL‐101 porous material is of outstanding bifunctional character as it is capable of simultaneously capturing and converting CO2 with low energy consumption and can be recovered easily by centrifugation. 相似文献
9.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(8):2155-2158
Amine‐linked (C−NH) porous organic cages (POCs) are preferred over the imine‐linked (C=N) POCs owing to their enhanced chemical stability. In general, amine‐linked cages, obtained by the reduction of corresponding imines, are not shape‐persistent in the crystalline form. Moreover, they require multistep synthesis. Herein, a one‐pot synthesis of four new amine‐linked organic cages by the reaction of 1,3,5‐triformylphloroglucinol (Tp) with different analogues of alkanediamine is reported. The POCs resulting from the odd diamine (having an odd number of −CH2 groups) is conformationally eclipsed, while the POCs constructed from even diamines adopt a gauche conformation. This odd–even alternation in the conformation of POCs has been supported by computational calculations. The synthetic strategy hinges on the concept of Schiff base condensation reaction followed by keto–enol tautomerization. This mechanism is the key for the exceptional chemical stability of cages and facilitates their resistance towards acids and bases. 相似文献
10.
Single‐Molecule Magnet Behavior of Individual Polyoxometalate Molecules Incorporated within Biopolymer or Metal–Organic Framework Matrices 下载免费PDF全文
Dr. Eric Rivière Shu Yang Dr. Catherine Roch‐Marchal Dr. Anne Dolbecq Dr. Corine Simonnet‐Jégat Prof. Nathalie Steunou Dr. Nathalie Leclerc‐Laronze Prof. Laurent Ruhlmann Prof. Talal Mallah Dr. Wolfgang Wernsdorfer Prof. Pierre Mialane 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6564-6574
The chemically and structurally highly stable polyoxometalate (POM) single‐molecule magnet (SMM) [(FeW9O34)2Fe4(H2O)2]10? (Fe6W18) has been incorporated by direct or post‐synthetic approaches into a biopolymer gelatin (Gel) matrix and two crystalline metal–organic frameworks (MOFs), including one diamagnetic (UiO‐67) and one magnetic (MIL‐101(Cr)). Integrity of the POM in the Fe6W18@Gel, Fe6W18@UiO‐67 and Fe6W18@MIL‐101(Cr) composites was confirmed by a set of complementary techniques. Magnetic studies indicate that the POMs are magnetically well isolated. Remarkably, in Fe6W18@Gel, the SMM properties of the embedded molecules are close to those of the crystals, with clear quantum tunneling steps in the hysteresis loops. For the Fe6W18@UiO‐67 composite, the molecules retain their SMM properties, the energy barrier being slightly reduced in comparison to the crystalline material and the molecules exhibiting a tunneling rate of magnetization significantly faster than for Fe6W18@Gel. When Fe6W18 is introduced into MIL‐101(Cr), the width of the hysteresis loops is drastically reduced and the quantum tunneling steps are smeared out because of the magnetic interactions between the antiferromagnetic matrix and the SMM guest molecules. 相似文献
11.
Noble Metals Can Have Different Effects on Photocatalysis Over Metal–Organic Frameworks (MOFs): A Case Study on M/NH2‐MIL‐125(Ti) (M=Pt and Au) 下载免费PDF全文
Dengrong Sun Wenjun Liu Dr. Yanghe Fu Zhenxing Fang Fangxiang Sun Prof. Dr. Xianzhi Fu Prof. Dr. Yongfan Zhang Prof. Dr. Zhaohui Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(16):4780-4788
M‐doped NH2‐MIL‐125(Ti) (M=Pt and Au) were prepared by using the wetness impregnation method followed by a treatment with H2 flow. The resultant samples were characterized by powder X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), X‐ray absorption fine structure (XAFS) analyses, N2‐sorption BET surface area, and UV/Vis diffuse reflectance spectroscopy (DRS). The photocatalytic reaction carried out in saturated CO2 with triethanolamine (TEOA) as sacrificial agent under visible‐light irradiations showed that the noble metal‐doping on NH2‐MIL‐125(Ti) promoted the photocatalytic hydrogen evolution. Unlike that over pure NH2‐MIL‐125(Ti), in which only formate was produced, both hydrogen and formate were formed over Pt‐ and Au‐loaded NH2‐MIL‐125(Ti). However, Pt and Au have different effects on the photocatalytic performance for formate production. Compared with pure NH2‐MIL‐125(Ti), Pt/NH2‐MIL‐125(Ti) showed an enhanced activity for photocatalytic formate formation, whereas Au has a negative effect on this reaction. To elucidate the origin of the different photocatalytic performance, electron spin resonance (ESR) analyses and density functional theory (DFT) calculations were carried out over M/NH2‐MIL‐125(Ti).The photocatalytic mechanisms over M/NH2‐MIL‐125(Ti) (M=Pt and Au) were proposed. For the first time, the hydrogen spillover from the noble metal Pt to the framework of NH2‐MIL‐125(Ti) and its promoting effect on the photocatalytic CO2 reduction is revealed. The elucidation of the mechanism on the photocatalysis over M/NH2‐MIL‐125(Ti) can provide some guidance in the development of new photocatalysts based on MOF materials. This study also demonstrates the potential of using noble metal‐doped MOFs in photocatalytic reactions involving hydrogen as a reactant, like hydrogenation reactions. 相似文献
12.
Incorporating Polyoxometalates into a Porous MOF Greatly Improves Its Selective Adsorption of Cationic Dyes 下载免费PDF全文
Ai‐Xue Yan Dr. Shuang Yao Prof. Yang‐Guang Li Dr. Zhi‐Ming Zhang Dr. Ying Lu Dr. Wei‐Lin Chen Prof. En‐Bo Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(23):6927-6933
Various polyoxometalates (POMs) were successfully immobilized to the mesoporous coordination polymer MIL‐101 resulting in a series of POM–MOF composite materials POM@MIL‐101 (POM=K4PW11VO40, H3PW12O40, K4SiW12O40). These materials were synthesized by a simple one‐pot reaction of Keggin POMs, tetramethylammonium hydroxide (TMAH), terephthalic acid (H2bdc), and Cr3+ ions. XRD, FTIR, thermogravimetric analyses (TG), inductively coupled plasma (ICP) spectrometry, and energy‐dispersive X‐ray spectroscopy (EDX) collectively confirmed the successful combination of POMs and the porous framework. Further, these composites POM@MIL‐101 with different loading of POMs were achieved by variation of the POM dosage. Notably, the uptake capacity of MIL‐101 towards organic pollutants in aqueous solution was significantly improved by immobilization of hydrophilic POMs into cages of MIL‐101. An uptake capacity of 371 mg g?1, comparable to that of the graphene oxide sponges, and much higher than that of the commercial activated carbon, was achieved at room temperature in 5 min when dipping 20 mg PW11V@MIL‐101 in the methylene blue (MB) solution (100 mL of 100 mg L?1 MB solution). Further study revealed that the POM@MIL‐101 composite materials not only exhibited a fast adsorption rate towards dye molecules, but also possessed of selective adsorption ability of the cationic dyes in wastewater. For example, the adsorption efficiency of PW11V@MIL‐101 (10 mg) towards MB (100 mL of 10 mg L?1) could reach 98 % in the initial 5 min, and it could capture MB dye molecules from the binary mixture of the MB and MO with similar size. Also, the POM@MIL‐101 materials could be readily recycled and reused, and no POM leached in the dye adsorption process. 相似文献
13.
Enhanced CO2 Adsorption Affinity in a NbO‐type MOF Constructed from a Low‐Cost Diisophthalate Ligand with a Piperazine‐Ring Bridge 下载免费PDF全文
Qian Mu Prof. Haiyan Wang Dr. Liangjun Li Chao Wang Ying Wang Prof. Xuebo Zhao 《化学:亚洲杂志》2015,10(9):1864-1869
A metal–organic framework (NPC‐6) with an NbO topology based on a piperazine ring‐bridged diisophthalate ligand was synthesized and characterized. The incorporated piperazine group leads to an enhanced adsorption affinity for CO2 in NPC‐6, in which the CO2 uptake is 4.83 mmol g?1 at 293 K and 1 bar, ranking among the top values of CO2 uptake on MOF materials. At 0.15 bar and 293 K, the NPC‐6 adsorbs 1.07 mmol g?1 of CO2, which is about 55.1 % higher than that of the analogue MOF NOTT‐101 under the same conditions. The enhanced CO2 uptake combined with comparable uptakes for CH4 and N2 leads to much higher selectivities for CO2/CH4 and CO2/N2 gas mixtures on NPC‐6 than on NOTT‐101. Furthermore, an N‐alkylation is used in the synthesis of the PDIA ligand, leading to a much lower cost compared with that in the synthesis of ligands in the NOTT series, as the former does not require a palladium‐based catalyst and borate esters. Thus, we conclude that NPC‐6 is a promising candidate for CO2 capture applications. 相似文献
14.
Thomas Wittmann Dr. Renée Siegel Nele Reimer Dr. Wolfgang Milius Prof. Dr. Norbert Stock Prof. Dr. Jürgen Senker 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):314-323
The resistance of metal–organic frameworks towards water is a very critical issue concerning their practical use. Recently, it was shown for microporous MOFs that the water stability could be increased by introducing hydrophobic pendant groups. Here, we demonstrate a remarkable stabilisation of the mesoporous MOF Al‐MIL‐101‐NH2 by postsynthetic modification with phenyl isocyanate. In this process 86 % of the amino groups were converted into phenylurea units. As a consequence, the long‐term stability of Al‐MIL‐101‐URPh in liquid water could be extended beyond a week. In water saturated atmospheres Al‐MIL‐101‐URPh decomposed at least 12‐times slower than the unfunctionalised analogue. To study the underlying processes both materials were characterised by Ar, N2 and H2O sorption measurements, powder X‐ray diffraction, thermogravimetric and chemical analysis as well as solid‐state NMR and IR spectroscopy. Postsynthetic modification decreased the BET equivalent surface area from 3363 to 1555 m2 g?1 for Al‐MIL‐101‐URPh and reduced the mean diameters of the mesopores by 0.6 nm without degrading the structure significantly and reducing thermal stability. In spite of similar water uptake capacities, the relative humidity‐dependent uptake of Al‐MIL‐101‐URPh is slowed and occurs at higher relative humidity values. In combination with 1H‐27Al D ‐HMQC NMR spectroscopy experiments this favours a shielding mechanism of the Al clusters by the pendant phenyl groups and rules out pore blocking. 相似文献
15.
Soonsang Hong Dr. Md. Rumum Rohman Dr. Jiangtao Jia Dr. Youngkook Kim Dr. Dohyun Moon Dr. Yonghwi Kim Dr. Young Ho Ko Prof. Dr. Eunsung Lee Prof. Dr. Kimoon Kim 《Angewandte Chemie (International ed. in English)》2015,54(45):13241-13244
The porphyrin boxes ( PB‐1 and PB‐2 ), which are rationally designed porous organic cages with a large cavity using well‐defined and rigid 3‐connected triangular and 4‐connected square shaped building units are reported. PB‐1 has a cavity as large as 1.95 nm in diameter and shows high chemical stability in a broad pH range (4.8 to 13) in aqueous media. The crystalline nature as well as cavity structure of the shape‐persistent organic cage crystals were intact even after complete removal of guest molecules, leading to one of the highest surface areas (1370 m2g?1) among the known porous organic molecular solids. The size of the cavities and windows of the porous organic cages can be modulated using different sized building units while maintaining the topology of the cages, as illustrated with PB‐2 . Interestingly, PB‐2 crystals showed unusual N2 sorption isotherms as well as high selectivity for CO2 over N2 and CH4 (201 and 47.9, respectively at 273 K at 1 bar). 相似文献
16.
Adsorptive Separation of Acetylene from Light Hydrocarbons by Mesoporous Iron Trimesate MIL‐100(Fe) 下载免费PDF全文
Sukyung Lee Kyoung Ho Cho Dr. Young Kyu Hwang Prof. Dr. Marco Daturi Prof. Chul‐Ho Jun Prof. Dr. Rajamani Krishna Prof. Dr. Jong‐San Chang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18431-18438
A reducible metal–organic framework (MOF), iron(III) trimesate, denoted as MIL‐100(Fe), was investigated for the separation and purification of methane/ethane/ethylene/acetylene and an acetylene/CO2 mixtures by using sorption isotherms, breakthrough experiments, ideal adsorbed solution theory (IAST) calculations, and IR spectroscopic analysis. The MIL‐100(Fe) showed high adsorption selectivity not only for acetylene and ethylene over methane and ethane, but also for acetylene over CO2. The separation and purification of acetylene over ethylene was also possible for MIL‐100(Fe) activated at 423 K. According to the data obtained from operando IR spectroscopy, the unsaturated FeIII sites and surface OH groups are mainly responsible for the successful separation of the acetylene/ethylene mixture, whereas the unsaturated FeII sites have a detrimental effect on both separation and purification. The potential of MIL‐100(Fe) for the separation of a mixture of C2H2/CO2 was also examined by using the IAST calculations and transient breakthrough simulations. Comparing the IAST selectivity calculations of C2H2/CO2 for four MOFs selected from the literature, the selectivity with MIL‐100(Fe) was higher than those of CuBTC, ZJU‐60a, and PCP‐33, but lower than that of HOF‐3. 相似文献
17.
A nanofiber metal–organic framework filter, a polyacrylonitrile (PAN) nanofiber membrane composite with an iron/2-amino-terephthalic acid-based metal–organic framework (MIL101(Fe)-NH2), was prepared by one-step electrospinning. MIL101(Fe)-NH2 was combined into the polymer nanofibers in situ. PAN-MIL101(Fe)-NH2 composite nanofiber membranes (NFMs) were prepared from a homogeneous spinning stock containing MIL101(Fe)-NH2 prebody fluid and PAN. Crystallization of MIL101(Fe)-NH2 and solidification of the polymer occurred simultaneously during electrospinning. The PAN-MIL101(Fe)-NH2 composite NFM showed that MIL101(Fe)-NH2 was uniformly distributed throughout the nanofiber and was used to adsorb and separate acidic organic ionic dyes from the aqueous solution. The results of Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analysis showed that MIL101(Fe)-NH2 crystals were effectively bonded in the PAN nanofiber matrix, and the crystallinity of MIL101(Fe)-NH2 crystals remained good, while the distribution was uniform. Owing to the synergistic effect of PAN and the MIL101(Fe)-NH2 crystal, the PAN-MIL101(Fe)-NH2 composite NFM showed a fast adsorption rate for acidic ionic dyes. This study provides a reference for the rapid separation and purification of organic ionic dyes from wastewater. 相似文献
18.
Probing the Structural Stability of and Enhanced CO2 Storage in MOF MIL‐68(In) under High Pressures by FTIR Spectroscopy 下载免费PDF全文
Yue Hu Bin Lin Peng He Prof. Youyong Li Prof. Yining Huang Prof. Yang Song 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18739-18748
The unique structural topology of metal–organic framework (MOF) MIL‐68, featuring two types of channels with distinct pore sizes, makes it a promising candidate for application in gas storage and separation. In this study, the behavior of as‐made and activated MIL‐68(In) was investigated in a diamond‐anvil cell under high pressure by in situ IR spectroscopy. The framework exhibits high stability under compression up to 9 GPa, whereas the bridging OH groups appear to be very sensitive to compression. Pressure‐induced structural modifications were found to be completely reversible for as‐made MIL‐68(In) but irreversible for the activated framework. Moreover, the addition of Nujol as pressure‐transmitting medium makes the framework more resilient to pressure. Finally, when loaded with CO2, the framework exhibited interesting differential binding affinities with CO2 in the hexagonal and triangular pores at different pressures. The pressure‐enhanced CO2 storage behavior and the guest–host interaction mechanism between CO2 and the MOF framework were explored with the aid of Monte Carlo simulations. These studies demonstrated great potential for MIL‐68(In) in gas‐storage applications that require extreme loading pressures. 相似文献
19.
Hctor Martínez Prez‐Cejuela Enrique Javier Carrasco‐Correa Ahmed Shahat Ernesto F. Sim‐Alfonso Jos Manuel Herrero‐Martínez 《Journal of separation science》2019,42(4):834-842
Metal‐organic frameworks consisting of amino‐modified MIL‐101(M: Cr, Al, and Fe) crystals have been synthesized and subsequently incorporated to glycidyl methacrylate monoliths to develop novel stationary phases for nano‐liquid chromatography. Two incorporation approaches of these materials in monoliths were explored. The metal‐organic framework materials were firstly attached to the pore surface through reaction of epoxy groups present in the parent glycidyl methacrylate‐based monolith. Alternatively, NH2‐MIL‐101(M) were admixed in the polymerization mixture. Using short time UV‐initiated polymerization, monolithic beds with homogenously dispersed metal‐organic frameworks were obtained. The chromatographic performance of embedded UV‐initiated composites was demonstrated with separations of polycyclic aromatic hydrocarbons and non‐steroidal anti‐inflammatory drugs as test solutes. In particular, the incorporation of the NH2‐MIL‐101(Al) into the organic polymer monoliths led to an increase in the retention of all the analytes compared to the parent monolith. The hybrid monolithic columns also exhibited satisfactory run‐to‐run and column‐to‐column reproducibility. 相似文献
20.
Qianchun Zhang Yanqun Yang Yongzhi Zhi Xingyi Wang Yun Wu Yuguo Zheng 《Journal of separation science》2019,42(3):716-724
A facile and efficient strategy is developed to modify aptamers on the surface of the magnetic metal‐organic framework MIL‐101 for the rapid magnetic solid‐phase extraction of ochratoxin A. To the best of our knowledge, this is the first attempt to create a robust aptamer‐modified magnetic MIL‐101 with covalent bonding for the magnetic separation and enrichment of ochratoxin A. The saturated adsorption of ochratoxin A by aptamer‐modified magnetic MIL‐101 was 7.9 times greater than that by magnetic metal‐organic framework MIL‐101 due to the former's high selective recognition as well as good stability. It could be used for extraction more than 12 times with no significant changes in the extraction efficiency. An aptamer‐modified magnetic MIL‐101‐based method of magnetic solid‐phase extraction combined with ultra high performance liquid chromatography with tandem mass spectrometry was developed for the determination of trace ochratoxin A with limit of detection of 0.067 ng/L. Ochratoxin A of 4.53–13.7 ng/kg was determined in corn and peanut samples. The recoveries were in the range 82.8–108% with a relative standard deviation (n = 5) of 4.5–6.5%. These results show that aptamer‐modified magnetic MIL‐101 exhibits selective and effective enrichment performance and have excellent potential for the analysis of ultra‐trace targets from complex matrices. 相似文献