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Physicochemical Properties of CuO2 (acac)2 Supported on Functionalized MCM41 Containing Thiourea Ligand  [PDF]
Amirah Ahmad,Hamizah Md. Rasid,Karimah Kassim
International Journal of Chemical Engineering and Applications , 2013, DOI: 10.7763/ijcea.2013.v4.249
Abstract: A new material is prepared by encapsulating functionalized-MCM41 with 2-hydroxy-2-mercaptopyrimidine (2-thiouracil) and copper acetate monohydrate. The functionalized-MCM41 was first synthesized by using Ludox as silica source and cetyltrimethylammonium bromide (CTABr) as template and was modified via co-condensation method using 3-aminopropyltriethoxysilane (APTES). The surface and textural of synthesized material have been characterized by using X-ray diffraction (XRD), N2 adsorption isotherms, BET surface area measurement, FT-IR, elemental analyzer and scanning electron microscopy (SEM). The low-angle XRD results indicated that the CuO2(acac)-Thio-APS-MCM41has similar XRD pattern as the mesoporous MCM41 although the intensity decreases. For high-angle XRD, the results show the presence of monoclinic CuO at 2θ = 35.3 and 38.6° while N2 adsorption and BET results were revealed that the CuO2(acac)-Thio-APS-MCM41 possessed a good mesoporous structural ordering and uniform mesoporosity. FTIR spectra confirmed that the organosilane group still retained in the pore channel of the CuO2(acac)-Thio-APS-MCM41 even after modification and the band of C=S and Cu=O also appeared in CuO2(acac)-Thio-APS-MCM41 spectra with the presence of thiourea ligand and copper. Hence, the characterization results were revealed that the synthesized material has an ordered hexagonal structure, a narrow pore size distribution, a high surface area and thiourea complex were successfully grafted onto the pores of functionalized-MCM41.
Synthesis of MCM–41 mesoporous molecular sieves containing heteroatoms and their catalytic activity

ZHOU Huafeng YANG Yongjin,ZHANG Jinsong,

材料研究学报 , 2009,
Abstract: MCM–41 mesoporous molecular sieves containing heteroatoms (Zn, Ni, Fe, Al, Cu, Ce) (T–MCM–41) were synthesized by direct hydrothermal process and were applied in the synthesis of dioctyl phthalate (DOP) in this paper. The effects of different heteroatoms incorporation on structure, specific surface area and pore volume, aciditity and catalytic activity of T–MCM–41 were investigated. The results show that T–MCM–41 which still remains the well–ordered hexagonal mesostructure of MCM–41 has high surface area (550–900 m2/g), large pore diameter (~3 nm). Meanwhile, it has high catalytic activity and selectivity in DOP synthesis because heteroatoms incorporation can produce acid centers. When T–MCM– 41 (T=Zn, Fe, Al, Cu) is used as the catalyst, the conversion of phthalic anhydride (PA) reaches above 95.5% and DOP selectivity reaches above 96.5% in 5 h. Moreover, T–MCM–41 has good stability and Al–MCM–41 holds good catalytic activity after being reused five times.
Immobilization of Lipase from Candida rugosa on Mesoporous MCM 41  [PDF]
Roberto Rodrigues de Souza, Renata D. M. Ferreira
Journal of Biosciences and Medicines (JBM) , 2014, DOI: 10.4236/jbm.2014.24011
Abstract:

The use of enzymatic route for production of biofuels is growing up due the mild reaction conditions that this method provides, as well as reducing SOx emission. To reduce costs, it’s necessary to immobilize the enzyme, making possible to use it continuously as biocatalyst. The aim of this work was to measure the influence of the mass of support and pH used for immobilization of commercial lipase from Candida rugosa acquired by Sigma laboratory. The immobilization method chosen was adsorption on mesoporous and hydrophobic support MCM 41, this has been treated with nitric acid 10% v/v to remove any organic residue. Then, 20 ml of enzymatic solution in phosphate buffer (pH 6.0, 7.0 and 8.0; 50 mM) and 1 g/L was placed under constant stirring with 0.30 and 0.45 g of support. Aliquots were taken from the reaction medium and analyzed by spectrophotometry at 10 minutes intervals. A volume of 0.2 ml of supernatant was put with 1.8 ml of substrate p-NFL at 0.18 g/L, and the absorbance at 410 nm was analyzed. In four cases there was a sharp reduction of supernatant’s activity at first 10 minutes, that ratifies the big affinity of the enzyme for the support and the negative influence of pH about the activity. Using the calibration curve, it was possible to calculate the final activity of each immobilization batch. This work suggests the occurrence of diffusional effects, which means that the enzyme mobility was restricted due the excessive amount of support, and then, it lost a part of accessibility to substrate, reflecting in not expressive activity values, and changing the state of ionization of the components of the system.

Preparation of Rhodamine B Fluorescent Poly(methacrylic acid) Coated Gelatin Nanoparticles  [PDF]
Zhenhai Gan,Jianhui Ju,Ting Zhang,Daocheng Wu
Journal of Nanomaterials , 2011, DOI: 10.1155/2011/753705
Abstract: Poly(methacrylic acid) (PMAA)-coated gelatin nanoparticles encapsulated with fluorescent dye rhodamine B were prepared by the coacervation method with the aim to retard the release of rhodamine B from the gelatin matrix. With sodium sulfate as coacervation reagent for gelatin, a kind of biopolymer with excellent biocompatibility, the formed gelatin nanoparticles were cross-linked by formaldehyde followed by the polymerization of methacrylic acid coating. The fluorescent poly(methacrylic acid) coated gelatin (FPMAAG) nanoparticles had a uniform spherical shape and a size distribution of ?nm. Infrared spectral analysis confirmed the formation of PMAA coating on the gelatin nanoparticles. Based on UV-Vis spectra, the loading efficiency of rhodamine B for the FPMAAG nanoparticles was 0.26?μg per mg nanoparticles. The encapsulated rhodamine B could sustain for two weeks. Favorable fluorescence property and fluorescence imaging of cells confirmed that the FPMAAG nanoparticles have promising biochemical, bioanalytical, and biomedical applications. 1. Introduction Recently, various kinds of functional nanoparticles have been developed and widely used in material and biomedical fields such as quantum dots (QDs) [1], colloidal gold nanoparticles [2], and magnetite (Fe3O4) nanoparticles [3] owing to their unique characteristics of large specific surface area, homogeneous size, higher sensitivity, and better function [4, 5]. Among them, fluorescent dye-doped nanoparticles have attracted special attention for several reasons. Firstly, they can provide high intensity of the fluorescent signal for the measurement. The traditional label method could have only one or a few fluorophores to signal one bimolecular recognition event. Fortunately, the dye-doped nanoparticles might contain hundreds to thousands of dye molecules, therefore, an intense fluorescence signal that is up to 30,000 fold better than that of a single organic fluorophore [6–8]. This extreme brightness makes them especially suitable for ultrasensitive bioanalysis and negates the need for additional reagents or signal amplification steps [9]. Secondly, the dye-doped fluorophore could have favorable photostability due to the exclusion of oxygen by matrix encapsulation. Other advantages are the good potential for surface modification with various biomolecules, and easy manufacturing process [6]. These advantages indicated that dye molecules encapsulated in the nanoparticles had high stability and retained their optical activity, thus providing a viable route for various applications with unique properties,
MD模拟研究含金属离子的MCM41对水的吸附  [PDF]
梁世强,徐靖中
工程热物理学报 , 2004,
Abstract: 本文采用MD模拟研究了分别含有Al3+,Cu2+和La3+等金属离子的中孔分子筛MCM41在较大温度范围内对水的吸附情况,通过考察水分子在孔内的局部平均密度分布,发现含有Al3+和La3+的MCM41对水有较好的吸附性能,表现在吸附量提高和脱附温度降低。我们认为其吸附性能提高的主要原因在于引入金属离子导致了壁面极性增加,增加了吸附表面的活性点,改变了壁面分子结构等几个方面。
Modeling of liquid hydrocarbon fuel production from palm oil via catalytic cracking using MCM -41 as catalyst  [PDF]
Ivan Yared,Hengky Kurniawan,Nico Wibisono,Yohanes Sudaryanto
Journal of Engineering and Applied Sciences , 2008,
Abstract: The objective of this study was to determine the reaction kinetics of the catalytic cracking of palm oil over MCM -41 as a catalyst at the higher C/O ratio and WHSV. The kinetic values obtained from this study can be used further for industrial purpose. In this study, palm oil was cracked using MCM -41 as a catalyst in a fixed bed micro-reactor. The experiment was conducted at the atmospheric pressure, with reaction temperature of 623.15 K, 673.15, and 723.15 K, Weight Hourly Space Velocity (WHSV) of 15, 17.5, 20, 22.5, 25, 27.5, and 30 h-1, and C/O (catalyst/oil) ratio of 1:32.5. The kinetic model used in this study was the three-lump model developed by Weekman, which involves parallel cracking of palm oil to Organic Liquid Product ( OLP ) and gas plus coke, with consecutive cracking of the OLP to gas plus coke. The model can represent the experimental data fairly well. From the study, the rate constant values k1, k2, k3 for reaction temperature of 623.15 K were found to be 9.499, 1.8967 and 0.15565 h-1, respectively. For reaction temperature of 673.15 K, the rate constant values were 20.0674, 3.9725 and 0.6330 h-1. For reaction temperature of 723.15 K, the rate constant values were 28.5494, 5.1498 and 0.6768 h-1. Using the Arrhenius equation, the activation energy is 41.5000, 37.7800 and 12.7437 kJ/mol for E1, E2, and E3, respectively. The pre-exponential factor k10, k20, and k30 obtained using the same equations were 30091.6, 2971.14 and 5.82 h-1, respectively.
MoO3在介孔分子筛MCM―41上分散状况的研究  [PDF]
郭锐,马骏
分子催化 , 2001,
Abstract: 采用XPS和XRD方法,测定了MoO3在未经改性的MCM-41及用Al2O3和TiO2改性后的MCM-41上的单层分散阈值,发现,MoO3在用Al2O3和TiO2改性后的MCM-41上的单层分散阈值比未经改性的MCM-41上的要提高三分之二。另外,借助MoO3/MCM-41、MoO3/Al2O3-MCM-41、MoO3/TiO2-MCM-41系列样品的比表面积和孔分布测定,研究了MoO3在未经改性的MCM-41及用Al2O3和TiO2改性后的MCM-41上的分散状况。
Selective Preparation of trans-Carveol over Ceria Supported Mesoporous Materials MCM-41 and SBA-15  [PDF]
Martina Stekrova,Narendra Kumar,P?ivi M?ki-Arvela,Oleg V. Ardashov,Konstantin P. Volcho,Nariman F. Salakhutdinov,Dmitry Yu. Murzin
Materials , 2013, DOI: 10.3390/ma6052103
Abstract: Ce-modified mesoporous silica materials MCM-41 and SBA-15, namely 32 wt % Ce–Si–MCM-41, 16 wt % Ce–H–MCM-41 and 20 wt % Ce–Si–SBA-15, were prepared, characterized and studied in the selective preparation of trans-carveol by α-pinene oxide isomerization. The characterizations of these catalysts were performed using scanning electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption and FTIR pyridine adsorption. Selective preparation of trans-carveol was carried out in the liquid phase in a batch reactor. The activity and the selectivity of catalyst were observed to be influenced by their acidity, basicity and morphology of the mesoporous materials. The formation of trans-carveol is moreover strongly influenced by the basicity of the used solvent and in order to achieve high yields of this desired alcohol it is necessary to use polar basic solvent.
Optical Imaging of Tumors with Copper-Labeled Rhodamine Derivatives by Targeting Mitochondria
Xin Yan, Yang Zhou, Shuang Liu
Theranostics , 2012,
Abstract: In this study, we evaluated Cu(L1) in two xenografted tumor-bearing (U87MG and MDA-MB-435) animal models to prove the concept that Cu(II)-labeled rhodamine derivatives, Cu(L) (L = L1 - L4) are useful as selective fluorescent probes for tumor imaging. We found that both multidrug resistance (MDR) negative U87MG gliomas and MDR-positive MDA-MB-435 breast tumors could be visualized. Because of tissue attenuation, accurate quantification of tumor uptake was difficult by optical methods. Therefore, 64Cu(L) (L = L1 - L4) were evaluated to compare their biodistribution properties. It was found that all four 64Cu radiotracers had a high glioma uptake (64Cu(L1): 5.71± 1.43 %ID/g; 64Cu(L2): 5.98 ± 2.75 %ID/g; 64Cu(L3): 4.28 ± 1.45 %ID/g; and 64Cu(L4): 6.25 ± 3.42 %ID/g) with 64Cu(L1) showing the highest tumor/background ratios. In athymic nude mice bearing MDA-MB-435 breast cancer xenografts, 64Cu(L4) showed almost identical normal organ uptake to that in the glioma-bearing animals, but its breast tumor uptake (1.26 ± 0.10% ID/g) was significantly lower (p < 0.001) than that in the glioma (6.25 ± 3.42% ID/g) because of MDR Pgps (P-glycoproteins) and MRPs (multidrug resistance-associated proteins) overexpressed in the xenografted MDA-MB-435 breast tumors. Results from cellular staining assays showed that both Cu(L2) and Cu(L4) were able to localize in mitochondria of U87MG cells, and their tumor selectivity was caused by the elevated negative mitochondrial potential in U87MG glioma cells as compared to that in human fibroblast cells. On the basis of these results, it was concluded that Cu(L) (L = L1 - L4) are useful as selective fluorescent probes for cellular staining assays and optical tumor imaging while 64Cu(L) (L = L1 - L4) have the potential as PET radiotracers for tumor imaging. This study represents a good example of dual modality imaging (PET and optical) using two agents, 64Cu(L) and Cu(L), with identical chemical composition. Future research will focus on developing new fluorescent probes with longer wavelength and reduced liver uptake.
Synthesis and characterization of simultaneously-impregnated Co-Mo-P on Al-MCM41. Effect of support precursors  [cached]
Agileo Hernández,José Escobar,José G. Pacheco,José A. de los Reyes
Revista de la Sociedad Química de México , 2004,
Abstract: Se sintetizaron materiales Al-MCM-41 (SiO2/Al2O3=200) a partir de distintas fuentes de Al y Si. Los sólidos calcinados (823 K) se caracterizaron por fisisorción de N2, difracción de rayos X y mediciones de acidez superficial. La muestra preparada a partir de tetraetil ortosilicato-Al(SO4)3 presentó área específica y volumen de poro menores (836 m2/g y 0.88 cm3/g, respectivamente) mientras que la menor incorporación de Al3+ a las paredes de los materiales MCM41 se registró cuando se utilizaron SiO2 y boemita como precursores. Se impregnó simultáneamente Co, Mo y P (~3, ~12.5 y ~1.6 % en peso) sobre Al-MCM41. La acidez superficial se incrementó notablemente después de la impregnación debido probablemente a la contribución de grupos PO4 3- depositados. Después de la sulfuración (H2S/H2, 673 K), el precursor con mejor textura y con la mayor proporción de Mo6+ octaédrico (el soportado sobre Al-MCM41 obtenido a partir de SiO2-Al(SO4)3) fue ~30 % más activo en la hidrodesulfuración (HDS) de dibenzotiofeno que una formulación comercial con soporte de Al2O3 y contenido similar de fase Co-Mo-P. La alta actividad en HDS y selectividad altamente orientada hacia la obtención de bifenil sugirieron buena promoción del Mo por el Co en el catalizador soportado sobre Al-MCM41.
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