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1.
The effect of cationic template on the adsorption of copper-phthalocyanine-3,4’,4",4"’-tetrasulfonic acid tetra-  相似文献   

2.
Nano‐molybdenum trioxide was prepared from nano‐molybdenum disulfide by simple firing in muffle furnace. Nano‐molybdenum trioxide was used as the extraction coating on the stainless steel wire. Four wires were filled in a polyetheretherketone tube to get an extraction tube. The tube was connected to the six‐port valve of a high performance liquid chromatograph, and the online analysis system was constructed. Extraction selectivity of the tube for different types of compounds, including polycyclic aromatic hydrocarbons, plasticizers, estrogens, anilines and neonicotinoids, was studied. Good enrichment ability for polycyclic aromatic hydrocarbons, but the extraction efficiency of others was not satisfactory. Using eight polycyclic aromatic hydrocarbons as the targets, an analytical method was established after optimizing main factors such as sampling volume, sampling rate, methanol content, and desorption time. The established method exhibited wide linear range to 0.016–20.00 μg/L and low limits of detection to 0.005 μg/L, and the enrichment factors can be up to 2443. The method was applied to the detection of trace polycyclic aromatic hydrocarbons in tap water and river water, and a good recovery was obtained. The tube showed good durability and chemical stability, and it still remained good extraction effect after more than 140 run.  相似文献   

3.
MCM‐41‐SO3H, an ordered mesoporous silica material in which MCM‐41 with covalently anchored sulfonic acid groups was used as an acidic catalyst for the rapid and ‘green’ synthesis of pyrano[3,2‐c]pyridine derivatives under solvent‐free conditions. Reusability of the catalyst, high yields, short reaction times, simplicity and easy workup are advantages of this novel synthetic procedure compared to the conventional methods reported in the literature.  相似文献   

4.
Despite the initial successes of gene delivery applications, they faced on several intrinsic drawbacks including toxicity and immunogenicity. Therefore, alternative gene‐delivery systems derived from recombinant peptides have emerged and is rapidly developing. Human epidermal growth factor receptor‐3 (HER3) shows high activity in tumor resistance to anti‐human epidermal growth factor receptor 2 (HER2) therapies. In this study, an affibody molecule against HER3 is conjugated to a biomimetic peptide RALA (an amphipathic and cationic peptide enriched with arginine) and the ability of the fusion vector for targeting HER3 and afterward delivering specific genes in breast cancer cells is evaluated. The results demonstrate that the biopolymeric platform, which contains an affibody‐conjugated RALA peptide, can effectively condense DNA into nanoparticles and target the overexpressed HER3 receptors in breast cancer cells and transfer specific genes. The use of such a recombinant biopolymer may pave the way for the development of sensitive and effective diagnostic and treatment tool for breast cancer.  相似文献   

5.
The establishment of Z‐scheme charge transfer between semiconductors is an effective method to improve the performance of hybridized semiconductor photocatalysts. Herein, the novel photocatalysts consisting of MoO3‐x and varying amounts of cadmium sulfide (CdS) nanospheres were successfully prepared via the one‐pot hydrothermal method in the presence of polyvinylpyrrolidone (PVP). It is indicated that the PVP not only served as the reducing agent for the formation of oxygen defects in MoO3‐x, but also the cross‐linking agent for the coupling between MoO3‐x and CdS. The CdS/MoO3‐x composite allowed for higher visible‐light photocatalytic performance for enhanced removal of methylene blue and tetracycline with an efficiency of 97.6% and 85.5%, respectively. The improved performance of the CdS/MoO3‐x composite was found to be mainly attributable to the remarkable charge carrier separation and transfer between CdS and MoO3‐x based on the favorable hole‐transporting nature and oxygen deficiencies of MoO3‐x. In addition, the hole‐oxidized photocorrosion of CdS was efficiently suppressed due to the presence of hole‐attractive MoO3‐x. At the solid interface, an oxygen‐defects‐mediated Z‐scheme charge carrier transfer pathway was proposed as the underlying mechanism for the superior photocatalytic reaction.  相似文献   

6.
The immobilization of copper complexes by covalent anchoring of the ligand on the surface of mesoporous MCM‐41 has been described. Bis[2‐(phenylthio)benzylidene]‐1,2‐ethylenediamine as a new N2S2 donor salen‐type ligand was covalently anchored onto nanopores of MCM‐41 coordinated with copper (I) halide. The organic–inorganic hybrid material was achieved readily using 3‐mercaptopropyltrimethoxysilane as a reactive surface modifier. 2‐Nitrobenzaldehyde was reacted smoothly with the thiol moieties in order to form functionalized nanoporous silica with carbaldehyde groups. The resulting supported organic moieties were converted to thiosalen ligand and coordinated with CuX (X = CN, Cl, Br, I). Characterization of the heterogeneous catalyst by X‐ray diffraction, N2 sorption, FT‐IR, diffuse reflectance UV‐visible and TGA techniques indicated successful grafting of the copper complex inside the nano‐channels of MCM‐41. The heterogenized catalyst was evaluated by the Mannich condensation reaction of aldehydes, amines and alkynes. In this reaction, the corresponding propargylamines were obtained as single products in good to excellent yields. Factors such as reaction temperature, solvent, catalyst loading, leaching and reusability of the catalyst also were discussed. The use of MCM‐41 as support permits an easier separation and recycles with only a marginal decrease in reactivity. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

7.
Despite the outstanding properties of hyperbranched polyglycerols such as biocompatibility and multifunctionality, enough attention has not been paid to the synthesis of their functional copolymers. This problem has limited the structural diversity of hyperbranched polyglycerols and hampers further developments and their practical usage. In this work, butyrolactone segments were incorporated into the backbone of polyglycerols by one‐pot ring‐opening copolymerization of a mixture of glycidol and γ‐butyrolactone in the presence of tin(II) 2‐ethylhexanoate. Poly(glycerol‐oligoγ‐butyrolactone)s were then crosslinked by 2,5‐thiophenediylbisboronic acid to obtain polymeric nanonetworks with 140 nm average size. Afterwards, the gold electrode was modified by the polymeric nano‐networks, and it was used for the determination of glucose, glycated hemoglobin, and Escherichia coli in phosphate buffer solution (pH = 9.0) through cyclic voltammetry and impedance spectroscopic. Taking advantage of the straightforward synthesis, cheap precursors and multifunctionality of poly(glycerol‐oligoγ‐butyrolactone)s, they could be used for real‐time sensing of a wide range of biosystems. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1430–1439  相似文献   

8.
Chiral N‐sulfonyldiamine was successfully anchored on mesoporous MCM‐41 silica. The MCM‐41‐supported chiral N‐sulfonyldiamine was used as an efficient heterogeneous chiral ligand in the asymmetric transfer hydrogenation of ketones. This heterogeneous system offered satisfactory enantioselectivities up to 94 % with excellent conversions.  相似文献   

9.
We report that nano‐emulsions can be creatively used as a morphology selective synthesis method to prepare not only nano‐grains but also nano‐fibers with high selectivity. Synthesis of the two different morphological materials was demonstrated using polyaniline synthesis as a model case. Polyaniline nano‐grains were synthesized from aniline molecules in nano‐size aqueous droplets as polymerization sites whose droplets were generated by inverse water‐in‐oil nano‐emulsion use, and polyaniline nano‐fibers were synthesized from aniline in aqueous nano‐dimensional channels as polymerization sites whose channels were generated by direct oil‐in‐water nano‐emulsion use containing high population of oil droplets. Using the approaches, we successfully synthesized nano‐fibers of 60 nm diameter with 0.5 µm length and also nano‐grains having diameter of 60–80 nm. The two different polymerization sites of nano‐scale dimension were made by changing the ratio among surfactant, aqueous aniline/HCl solution, and oil, i.e. organic solvent. We found the nano‐fibers synthesized from the channels formed by the direct oil‐in‐water nano‐emulsion have higher bulk electrical conductivity than the nano‐grains which were synthesized from the droplets formed by the inverse water‐in‐oil emulsion. We also found that the emulsion use allows us to use a room temperature synthesis unlike conventional synthesis methods which require to use ice bath temperature. Physical properties of both nano‐fibers and nano‐grains synthesized were characterized by Fourier transform infrared (FTIR), UV–Vis spectra, scanning electron microscopy (SEM), and four probes conductivity measurement. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

10.
It's highly significant to develop a novel catalyst, which can be active at a wide range of pH, for an effective photo‐Fenton reaction. In this work, α‐FeOOH?MoO3 nanorod was prepared by a one‐step hydrothermal method and applied in photo‐Fenton degradation of organic pollutants. Benefit from the electron migration mechanism of Z‐scheme and excellent photoelectric performance, the catalyst exhibited superior photo‐Fenton activity in degradation of organic pollutants. In addition, the catalyst holds good stability after 5 recycles. These results demonstrated that this catalyst has wide application prospect in organic wastewater treatment.  相似文献   

11.
We investigated detailed conditions for synthesizing the tubular form of MCM‐41 mesoporous aluminosilicate. The method is the delayed neutralization method in which the rate of neutralization is one of the controlling factors. Rapid neutralization results in the particulate form while gradual neutralization leads to tubules. It is found that the tubule morphology has several sub‐categories. There are thick‐walled, think‐walled hollow tubular MCM‐41 and solid core tubules. There are void structures in the channel framework that makes the nanochannels to be effectively interconnected.  相似文献   

12.
o‐Phenylenediamine derivatives readily react with benzoyl chloride derivatives in the presence of MCM‐41 as catalyst to yield 2‐substituted benzimidazoles in very good yields.  相似文献   

13.
The catalytic efficiency of ammonium dihydrogenphosphate was evaluated in the two heterogeneous forms of NH4H2PO4/MCM‐48 and NH4H2PO4/MCM‐41, as mesoporous catalysts, in the solvent free synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones through one‐pot three‐component condensation of ethyl acetoacetate, an aryl aldehyde and urea. Different reaction parameters including catalytic efficacy, solvent effect, and urea concentration are considered.  相似文献   

14.
Titanium‐containing MCM‐41 (Ti‐MCM‐41) modified glassy carbon electrode (GCE) can exhibit an excellent electrocatalytic activity towards the oxidation of β‐Nicotinamide adenine dinucleotide (NADH). A dramatic decrease in the over‐voltage of NADH oxidation reaction is observed at 0.28 V (vs. SCE). The modified electrode is found to be stable and reproducible. The electrode shows a linear response for a wide range of 10–1200 μM NADH and the detection limit is 8.0 μM. Ti‐MCM‐41 mesoporous molecular sieves provide an efficient matrix for development of NADH biosensors and the prepared electrode not only can be used to detect the concentration of NADH in biochemical reaction, but also as the potential matrix of the construction of dehydrogenases biosensor.  相似文献   

15.
Sulfur‐resistant methanation of syngas was studied over MoO3–ZrO2 catalysts at 400°C. The MoO3–ZrO2 solid‐solution catalysts were prepared using the solution combustion method by varying MoO3 content and temperature. The 15MoO3–ZrO2 catalyst achieved the highest methanation performance with CO conversion up to 80% at 400°C. The structure of ZrO2 and dispersed MoO3 species was characterized using X‐ray diffraction and transmission electron microscopy. The energy‐dispersive spectrum of the 15MoO3–ZrO2 catalyst showed that the solution combustion method gave well‐dispersed MoO3 particles on the surface of ZrO2. The structure of the catalysts depends on the Mo surface density. It was observed that in the 15MoO3–ZrO2 catalyst the Mo surface density of 4.2 Mo atoms nm?2 approaches the theoretical monolayer capacity of 5 Mo atoms nm?2. The addition of a small amount of MoO3 to ZrO2 led to higher tetragonal content of ZrO2 along with a reduction of particle size. This leads to an efficient catalyst for the low‐temperature CO methanation process.  相似文献   

16.
Nanosized MCM‐41‐SO3H based on ordered mesoporous silica material with a covalent sulfonic acid group was synthesized and used as acid catalyst for the new, simple, convenient and green synthesis of 2,4,5‐trisubstituted and 1,2,4,5‐tetra‐substituted imidazoles. Also some of synthesis products are new. Echo‐friendly protocol, short reaction times, easy and quick isolation of the products and excellent yields are the main advantages of this procedure.  相似文献   

17.
The effect of addition of poly(ethylene glycol)‐400 (PEG‐400) and carbon (0, 1, 2 and 3 wt%) as substrates were investigated systematically to get the desired phase of carbon‐doped MoO3 material. The carbon source was prepared from the Acacia arabica plant wood. The resulting samples were calcined at 500°C. The effect of PEG‐400 and carbon composite on the structure, particle size and morphology were investigated. The prepared samples were characterized by XRD, SEM‐EDS and FT‐IR techniques. The samples with PEG‐400 and carbon addition give better control of particle size and porosity. The prepared catalysts were tested for the synthesis of 3,4‐dihydropyrimidones via the Biginelli‐type condensation reaction. This new method consistently has the advantage of excellent yields (88%–93%) and short reaction times (1.5–3 h) than do classical Biginelli reaction conditions.  相似文献   

18.
Novel boron‐dipyrromethene (BODIPY)‐bridged 22‐oxacorrole dyads, using meso‐pyrrolyl 22‐oxacorrole as a key synthon, have been synthesized. The reactivity of the meso‐pyrrolyl group of 22‐oxacorrole was exploited to synthesize the first examples of BODIPY‐bridged 22‐oxacorrole dyads in ≈40 % yield. The dyads are stable and exhibited interesting spectral and electrochemical properties.  相似文献   

19.
Palladium nanoparticle‐incorporated mesoporous organosilica (MCM‐41‐Crown.Pd) was synthesized via the grafting of dibenzo‐18‐crown‐6‐ether moieties on the MCM‐41 surface, followed by reaction of the nanocomposite with palladium acetate and then its reduction in ethanol. The cavity of the immobilized dibenzo‐18‐crown‐6 as host material can stabilize the palladium nanoparticles effectively and prevent their aggregation and separation from the surface. The structure of the nanocomposite was characterized using various techniques. The catalytic properties of the nanocomposite in the Heck coupling reaction, one of the most useful transformations in organic synthesis, between aryl halides and olefins in water were also explored. The main advantages of the method are low cost, high yields, easy work‐up and short reaction time. The nanocatalyst can be easily separated from a reaction mixture and was successfully examined for seven runs, with a slight loss of catalytic activity.  相似文献   

20.
MCM‐41‐supported bidentate phosphine rhodium complex (MCM‐41‐2P‐RhCl3) was conveniently synthesized from commercially available and cheapγ‐aminopropyltriethoxysilane via immobilization on MCM‐41, followed by reacting with diphenylphosphinomethanol and rhodium chloride. It was found that the title complex is a highly efficient catalyst for the hydrosilylation of olefins with triethoxysilane and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity.  相似文献   

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