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Samaheh Sadjadi Naeimeh Bahri-Laleh Mehdi Nekoomanesh-Haghighi Farshid Ziaee Sedva Dehghani Sedigheh Shirbakht 《International Journal of Polymer Analysis and Characterization》2019,24(6):556-570
In this study, three middle range α-olefin monomers including 1-hexene, 1-octene, and 1-decene were oligomerized using conventional AlCl3/H2O catalytic system. Molecular weight and microstructure of the oligomers were analyzed by GPC and 1HNMR, respectively. By 1HNMR spectra, both internal (CHR=CHR′ and CHR=CR′R′′) and external (CH2=CR′R′′) olefins containing di and tri-substituted C=C bonds were detected. After successful oligomerization, synthesized polyα-olefins underwent hydrogenation process using Pd(0)-Hal catalyst to yield synthetic oils of PHex, POct, and PDec, respectively and then completion of the hydrogenation was confirmed by 1HNMR spectroscopy. The microstructure of the synthesized oligomers was rationalized using the ratio under the peak of CH?+?CH2/CH3 hydrogens (S1/S2) in 1HNMR spectra and the degree of oligomerization obtained from Mn. According to the results, the best match between theoretical and real S1/S2 is obtained when considering double bond isomerization in the synthesized PAOs. By knowing PAO molecular weight, a relationship between monomer type and S1/S2 in the PAO homopolymers was detected. Our suggested methodology can be generalized to the unknown PAO homopolymers to unravel their monomer type by simple 1HNMR and GPC analyses. 相似文献
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We present a study on the synthesis, characterization, and application of phthalhydrazide‐functionalized MCM‐41 (P‐MCM‐41) as a novel and efficient heterogeneous basic catalyst. The described catalyst was fully characterized via various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X‐ray (EDX), X‐ray diffraction (XRD), and Fourier transform infrared (FT‐IR). P‐MCM‐41 efficiently catalyzed the four‐component reaction of arylaldehydes, Meldrum's acid, alkyl isocyanides, and isoquinoline in CHCl3 to prepare pyrrolo[2,1‐a]isoquinolines in good yields. 相似文献
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Magnetic nanoparticles (MNPs) functionalized with methotrexate (MTX)-conjugated bovine serum albumin (BSA) as a biocompatible drug delivery vehicle were synthesized using a facile method. Characterization of the functionalized MNPs (Fe3O4@BSA-MTX NPs) was performed using various techniques including UV–visible spectroscopy, dynamic light scattering, vibrating sample magnetometry and X-ray diffraction. The particle size and zeta potential of Fe3O4@BSA-MTX NPs were 105.7 ± 3.81 nm (mean ± SD) and −18.2 mV, respectively. MTX release from Fe3O4@BSA-MTX NPs showed an enzyme-dependent release pattern. Hemo-biocompatibility of Fe3O4@BSA-MTX NPs was confirmed using hemolysis test. In addition, the cytotoxicity of functionalized MNPs and free MTX against MCF-7 cell line was investigated using MTT assay. The results of experiments revealed that the Fe3O4@BSA-MTX NPs as a biocompatible carrier could improve the therapeutic effect of MTX. 相似文献
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A simple and efficient synthesis of 2‐amino‐4‐aryl thiazole derivatives was carried out through the reaction of substituted acetophenones and thiourea using three different types of catalytic systems including N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide [TBBDA], poly(N,N′‐dibromo‐N‐ethylbenzene‐1,3‐disulfonamide) [PBBS] and a combination of TBBDA and nano‐magnetic catalyst supported with functionalized 4‐amino‐pyridine silica (MNPs@SiO2‐Pr‐AP). The results showed that the use of TBBDA along with the MNPs@SiO2‐Pr‐AP gains the highest yields of the products in the shortest reaction time. 相似文献
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SBR compounds including the N-isopropyl-N’-phenyl-p-phenylenediamine-modified clay(organoclay) were prepared.Effects of modified clay and antioxidant(IPPD) contents on mechanical and rheological properties of SBR composites were studied.FTIR results confirmed that the clay was chemically modified by IPPD and changed into an organoclay.X-ray diffraction(XRD) results confirmed the increase in interlayer distance of the clay due to the insertion of IPPD.Rheological and cure characteristics of SBR compounds were determined using RPA(Rubber Process Analyzer) and rheometer.Scorch time and cure time of SBR compounds decreased with introduction of the organoclay.Mechanical properties and heat aging resistance of the SBR composites were improved significantly by incorporation of the organoclay. 相似文献
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Sadegh Hassani S Kim YG Borguet E 《Langmuir : the ACS journal of surfaces and colloids》2011,27(24):14828-14833
Self-assembled monolayers of a water-insoluble porphyrin, tetraphenyl porphyrin (TPP), in the presence of an aqueous electrolyte were characterized in situ with electrochemical scanning tunneling microscopy (EC-STM) at working electrode potentials of between 0.5 and -0.2 V. Isolated domains of TPP monolayers with differing orientation were observed on Au(111) in 0.1 M HClO(4) over this entire potential window. Individual TPP molecules could be resolved over a range of 700 mV, from open circuit potential (OCP) to near the hydrogen evolution potential. The unit cell is square, and the distance between neighboring molecules is about 1.4 ± 0.1 nm. High-resolution images allow the internal molecular structure to be discerned. No changes in the STM contrast of individual molecules were observed as the potential was changed. In a neutral electrolyte (0.1 M KClO(4), pH ~6), the potential range of stability of ordered structures is reduced. On HOPG, TPP forms ordered hexagonal structures with a lattice constant of about 2.6 nm in the double-layer potential region in 0.1 M HClO(4). 相似文献
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Sedigheh Borhani Seyed Gholamreza Etemad Seyed Abdolkarim Hosseini Ravandi 《Heat and Mass Transfer》2011,47(7):807-811
In this study a non-conventional electrospinning technique was designed for the production of high bulky polyacrylonitrile
(PAN) nanofiber mats. Optimum nanofiber mats are achieved with 15 wt.% solution of PAN in dimethylformamide. Such mats result
in a bulk porosity which is as high as 99.9 and a density as low as 0.84 × 10−3 g/cm3. The effect of the porosity of nanofiber mats on the air permeability and coupled heat and moisture transfer of fibers was
investigated. Based on the results, high bulky nanofiber mats possess high heat and moisture transfer. Experimental data reveal
that upon a slight decrease in the bulk porosity, air permeability and heat transfer decrease noticeably, while moisture transfer
variation is low. 相似文献