106 resultados para Dimeric Surfactants
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近年来,由于有机和无机成分在纳米尺寸上的结合而带来的优异性能使得聚合物/蒙脱土纳米复合材料得到广泛关注。在诸多方法中,因能够使用传统的聚合物熔融挤出、共混等加工设备而无需额外的设备投资,投资低、见效快而且对周围环境没有污染等优点,熔融插层法倍受青睐。然而,通常认为亲油性聚合物无法直接插层蒙脱土,而需要预先用插层剂处理蒙脱土。大多数聚合物是亲油性的,这将大大增加制备材料的成本和工艺的复杂性,并因引入了小分子插层剂而有损材料性能的提高,从而阻碍了该技术的应用和推广。本文从理论上研究了插层剂用量对有机化蒙脱土及聚合物/蒙脱土纳米复合材料微观结构的影响,探索一种无需改性蒙脱土或用很少插层剂改性蒙脱土的制备聚合物/蒙脱土纳米复合材料的方法。1.系统地改变插层剂用量,制备不同的有机化蒙脱土。通过广角X射线衍射、热失重分析、索氏抽提器抽提、差热分析和付立叶红外分析等表征手段,研究了插层剂插层机理以及插层剂在蒙脱土层间的排列方式,为进一步研究有机化蒙脱土在聚合物树脂中的分散奠定基础。结果表明,插层剂插层蒙脱土机理和在蒙脱土层间的排列方式随着插层剂用量的变化而不同。2.用不同的亲油性聚合物熔融插层有机化蒙脱土以制备相应的聚合物/蒙脱土纳米复合材料。用广角嘴射线衍射仪和透射电子显微镜分析研究了蒙脱土在聚合物/蒙脱土纳米复合材料中分散状态。结果表明,随着插层剂用量的减少,蒙脱土片层在聚合物树脂中的分散逐渐由插层型过渡到剥离型,即减少改性蒙脱土时插层剂用量有利于蒙脱土在纳米尺寸上分散于聚合物树脂中。3.用不同的亲油性聚合物直接熔融插层未改性的蒙脱土,广角X射线衍射仪和透射电子显微镜表征结果表明,与蒙脱土片层有相互作用的亲油性聚合物能够直接熔融插层未改性的蒙脱土,获得剥离或插层型聚合物/蒙脱土纳米复合材料,这对于蒙脱土在聚合物改性中的应用具有重要的实际意义和理论意义。4.用共同的母料制备聚丙烯/酸配化聚丙烯/蒙脱土纳米复合材料和尼龙12/酸醉化聚丙烯/蒙脱土纳米复合材料,用广角X射线衍射仪和透射电子显微镜对比分析蒙脱土在聚合物中分散的差异,从而了解聚丙烯与酸配化聚丙烯之间的增容作用对蒙脱土在聚丙烯树脂中分散的影响;同时,用尼龙11和酸配化聚丙烯共插层蒙脱土制备聚丙烯/蒙脱土纳米复合材料,并探讨其增容机理。
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利用表面活性剂去除土壤中难降解的多环芳烃,近年来得到了较多的应用.但对其去污机理及两者共存时的复合毒性,国内外研究甚少.该篇论文以六种不同离子类型、分子结构的表面活性剂和以菲为多环芳烃的代表,研究了表面活性剂对菲降解的影响,和与菲共存时的复合毒性,以及表面活性剂对菲在模拟生态系统中的迁移转化规律的影响.
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本论文由四章组成。第一、二和三章分别报道了双花千里光、川芎和宽叶羌活的化学成分研究。从三种药用植物中共分离和鉴定了40 个化学成分,其中8个为新化合物。第四章概述了藳本属植物及日本川芎的化学成分研究进展。 第一章包括三个部分。第一部分报道双花千里光(Senecio dianthus Franch.)地上部分乙醇提取物的化学成分。采用正、反相硅胶柱层析等各种分离方法,从中共分离出8 个艾里莫酚型倍半萜内酯,其中5 个是新化合物,并且有1 个为首次发现的连接了含氮原子取代基的艾里莫酚型倍半萜内酯。它们的结构经MS、IR、NMR及X-单晶衍射等解析方法确定为2b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (1)、6b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (2)、2b-angeloyloxy-8b,10b- dihydroxyeremophil-7(11)-en-8a,12-olide (3)、2b-angeloyloxy-8a-hydroxyeremophil-7(11),9(10)-dien-8b,12-olide (4)和8b-amino-10b- hydroxyleremophil-7(11)-en-8a,12-olide (5)。这8 个倍半萜内酯经体外生物活性测试表明均具有通过抑制巨噬细胞增殖抵制破骨细胞增生的活性。第二部分对艾里莫酚型倍半萜内酯的质谱裂解规律进行了初步探讨。第三部分报道双花千里光茎、和叶花的挥发油成分分析。采用传统水蒸气蒸馏法分别提取了双花千里光茎、叶和花的挥发油,用气相色谱-质谱联用(GC-MS)技术分别分离鉴定了其化学成分,从茎、叶和花挥发油中各分离和鉴定出70、80 和73 种化学成分,分别占挥发油总量的91.2%、85.7%及93.4%。 第二章包括两个部分。第一部分报道川芎(Ligusticum chuanxiong Hort.)根茎乙醇提取物的化学成分。通过正、反相硅胶柱层析等分离纯化和MS、NMR及X-单晶衍射等解析方法,共分离鉴定了21 个化合物,结构类型分属于苯酞、二聚苯酞、香豆素和脂肪酸类。其中2 个为结构比较新颖的二聚苯酞类化合物:chuanxiongnolide A (19)和chuanxiongnolide B (20),化合物19 的结构经X-单晶衍射得到确证。第二部分报道川芎挥发油的化学成分。采用不同的提取方法(溶剂萃取法、水蒸气蒸馏法、CO2 超临界流体萃取法)提取川芎挥发油,同时采集不同产地(四川彭县、四川郫县、云南鹤庆)及不同品质(川芎、奶芎、苓子)的川芎产品,利用GC-MS 技术分离鉴定其挥发油的化学成分,计算各成分的相对含量,并对比分析其中的异同。 第三章报道宽叶羌活(Notopterygium forbesii Boiss.)根茎化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR 等解析方法,共分离鉴定了13 个化合物,结构类型分属于香豆素、二氢异香豆素、甾体和羧酸类。其中1 个新二氢异香豆素类成分鉴定为6-methoxy-hydrangenol (37)。 第四章概述了藳本属植物及日本川芎化学成分的研究进展。 This dissertation consisted of four chapters. The former three chaptersrespectively elaborated the phytochemical investigation of three herbal medicines:Senecio dianthus Franch., Ligusticum chuanxiong Hort. and Notopterygium forbesiiBoiss.. Forty compounds, including eight new ones, were isolated and identified byspectral and chemical evidence. The fourth chapter elaborated the study progress ofchemical constituents of Ligusticum genus and Cnidium offcinale. The first chapter consisted of three parts. The first part is about the chemicalconstituents of ethanol extraction and essential oils from the aerial parts of S. dianthu.Eight eremophilenolides were isolated and identified. Among them, five ones are newcompounds and one of them is a novel eremophilenolide attched with an amino group.The structures of the new compounds were identified as 2b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (1),6b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (2),2b-angeloyloxy-8b,10b-dihydroxyeremophil-7(11)-en-8a,12-olide (3),2b-angeloyloxy-8a-hydroxyeremophil-7(11),9(10)-dien-8b,12-olide (4) and8b-amino-10b-hydroxyeremophil-7(11)-en-8a,12-olide (5) by spectral evidence andX-ray crystallography analysis. All the compounds were evaluated for theiranti-osteoclstogenesis activity using a proliferation inhibit assay with microphagecells. The second part elementarily discussed the characteristic fragmentation oferemophilenolides isolated from S. dianthus in ESI-MS.The latter part is about thechemical constituents of essential oil extracted from stems, leaves and flowers of S.dianthus with steam distillation. By the GC-MS analysis, 70, 80 and 73 compoundswere respectively isolated and identified which accounted for more than 91.2%, 85.7% and 93.4% of total essential oil. The second chapter, including two parts, is about the the chemical constituents ofethanol extraction and essential oils from rhizomes of L. chuanxion. In the first part, twenty-one compounds were isolated and iedntified. Two ones are novel dimericphthalides and the structures were suggested as chuanxiongnolide A (19) andchuanxiongnolide B (20) by spectral evidence and confirmed by X-raycrystallography analysis. In the second part, the samples were collected from differentextract techniques (solvent extraction, steam distillation and supercriticalfluid extraction), different habitats (Peng and Pi counties, Sichuan province; Heqing,Yunnan province) and different qualities (Chuanxiong, Naixiong and Lingzi). Thechemical constituents of essential oil from L. chuanxiong were analyzed by GC-MS and were compared each other. The third chapter is about the chemical constituents of rhizomas of N. forbesii,which belongs to a endemic genus of China. Thirteen compounds were isolated andidentified. One of them is a new dihydroisocoumarin and the structure was identifiedas 6-methoxy-hydrangenol (37) by spectral evidence. The fourth chapter is a review on study progress of chemical constituents ofLigusticum species and Cnidium offcinale.
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本论文研究了利用三孢布拉氏霉(Blakeslea trispora)发酵产β-胡萝卜素的培养条件。主要包括:发酵培养基的确定,发酵条件的优化。还考察了发酵菌丝体中β-胡萝卜素的提取方法及薄层层析等。 首先研究了培养基成分对三孢布拉氏霉发酵产β-胡萝卜素的影响。确立了玉米淀粉作为碳源,黄豆粉(热榨)作为氮源,棉籽油作为植物油的发酵培养基配方,其成分为:玉米淀粉 3%,黄豆粉(热榨) 2%,棉籽油 3%,KH2PO4 0.2%,MgSO4·7H2O 0.2%,维生素B1 0.002%,pH值6.0。 其次,通过比较不同的发酵影响因子,分别得到最适的条件:如三孢布拉氏霉正负菌接种比例为1.3:0.7,培养基pH值为7.0(灭菌后),发酵促进因子为Triton X-100。并采用正交试验法,确定其最佳发酵条件为正负菌接种比例1.3/0.7,发酵培养基pH为7.0,在培养基中添加表面活性基Triton X-100 0.08%。使该菌株产β-胡萝卜素的量达到0.73g/L,较初始发酵条件提高了3.3倍。 研究中还找到一个简便有效的对β-胡萝卜素的提取方法,选用盐酸-热处理法进行细胞破壁,并选用沸程为60~90℃的石油醚进行萃取。 用三孢布拉霉菌丝体内类胡萝卜索的石油醚提取液点样于硅胶G板,以丙酮:石油醚(5:95)为展开剂能将β-胡萝卜素与其它类胡萝卜索分离。该方法简便快速,并有一定实用价值。 The fermentative conditions of β-carotene by Blakeslea trispora have been investigated. These conditions include fermentation medium, the optimization of some fermentation factor. The extracting methods and the TLC of carotenoids were also researched. Firstly, the effects of composition of fermentation medium on the yield of β-carotene were studied. the results showed that the best fermentation medium was corn starch 3%,soybean power 2%,cottonseed oil 3%,KH2PO4 0.2%,MgSO4·7H2O 0.2%,vitamin B1 0.002%,pH value 6.0. Secondly, through compared some factors, such as different proportion of plus and minus strains, pH value, nonionic surfactants, respective best values have been obtained. The best proportion of plus and minus strains is 1.3:0.7, pH value of fermentation medium (sterilized) is 7.0, fermentation accelerant which acts as surfactants is Triton x-100. Farther on, the fermentative conditions were optimized through orthogonal experiment, the optimization showed that proportion of plus and minus strains is 1.3:0.7,pH value is 7.0, content of Triton x-100 is 0.08%. And the yield of β-carotene reached 0.73g/L, which was up to 3.3 times through the fermentation. In the extracting study, it has showed hydrochloric acid-heat treatment is a simple, convenient and effective extracting methods is which was used to destroy the cell wall, and the extracting organic solvent is petroleum ether whose boiling range is 60~90 ℃. In the TLC experiments, extracting contents in the petroleum ether were spotted in the silicagel plate, and the mixed liquor of acetone and petroleum ether (5:95) is developping agent, which can distinguish β-carotene from other carotenoids. It is a simple and quick technique.
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Experimental data are presented to show the influence of the enhanced oil recovery system's components, alkali, surfactant, and polymer, on the demulsification and light transmittance of the water separated from the emulsions. Among which, the effects of surfactants, polyoxyethylene (10) alkylphenol ether (OP-10) and sodium petroleum sulfonate (CY-1) on emulsion stability, are the strongest of any component, the effects of polymer, hydrolytic polyacrylamide (HPAM) 3530S, on emulsion stability are the weakest. This research also suggests a possible emulsion minimization approach, which could be implemented in refineries utilizing microwave radiation. Compared with conventional heating, microwave radiation can effectively enhance the demulsification rate by an order of magnitude and increase the light transmittance of the water separated from the emulsions. The demulsification efficiency may reach 100% in a very short. time under microwave radiation.
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Concentrations of the weakly oestrogenic degradation products of alkylphenol polyethoxylate (APE) surfactants (nonylphenol, octylphenol, nonylphenol monoethoxylate and nonylphenol diethoxylate) were measured in water and sediments from British rivers and estuaries collected during 1994 and 1995. In addition, a series of samples of tissues of wild fish from the River Aire, and from a laboratory dosing experiment were analysed for alkylphenols, to assess the degree of bioaccumulation of these compounds. Measurable concentrations of APE residues were recorded in the River Aire (15–76 μg/l total extractable alkylphenols), the River Mersey (6–11 μg/l) and the Tees estuary (up to 76 μg/l). These levels exceed, or are close to, the no observed effect concentration for the induction of vitellogenesis in caged trout (5–20 μg/l total extractable alkylphenols), and may be sufficient to exert an oestrogenic effect on fish populations in these areas. A sediment sample from Bingley on the River Aire contained 15 μg/g (dry weight) nonylphenol, and concentrations in sediments from the Tees and Mersey estuaries exceeded 1 μg/g. These rivers receive a variety of trade waters via sewage treatment works (STW) effluents containing significant concentrations of APE. Elsewhere, concentrations in water and sediments were near or below limits of detection and biological effects are unlikely, suggesting that any oestrogenic effects observed in sewage outfalls and rivers not directly impacted by APE-containing trade-waters may be caused by other chemicals. Analysis of samples of trout muscle taken from a tank dosed at 65 μg/l nonylphenol indicated a bioaccumulation factor of between 90 and 125 after 3 weeks exposure. Samples of wild fish from the River Aire contained up to 0.8 μg/g nonylphenol in the muscle, a tissue bioaccumulation factor of approximately 50 relative to measured concentrations in water samples. A series of fish samples taken from offshore for food quality assurance purposes contained no detectable levels of APE residues (0.05–0.1 μg/g nonylphenol).
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The conformation of bovine serum albumin (BSA), as well as its interactions with negatively charged mica surfaces in saline solutions of different pH values, have been studied by small-angle neutron scattering (SANS) and chemical force microscopy (CFM), respectively. A new approach to extract the contribution of elementary interactions from the statistically averaged force-extension curves through self-consistent fitting was proposed and used to understand the effects of pH on the interactions and conformation of BSA in saline solutions. When pH increases, the SANS results reveal that the sizes of BSA molecules increase slightly, while the statistical analysis of the CFM results shows that the averaged pull-off force for the elongation monotonously decreases. The decrease of pull-off force with the increase of pH results from the decrease in the strength of hydrogen bonding and the number of interaction pairs, as well as the slight increase of the strength of van der Waals interaction. When pH approaches the isoelectric point (pI) of BSA, results from both SANS and CFM suggest a loss of long-range interactions in BSA molecules. Our results also suggest that the force-extension curve is mainly contributed by the van der Waals interaction. The combination of SANS and CFM provides new insight to understand the interactions and conformation of BSA molecules
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Hydrogenolysis of mono(cyclopentadienyl)-ligated rare-earth-metal bis(alkyl) complexes Cp'Ln-(CH2SiMe3)2(THF) (Ln = Y (1a), Dy (1b), Lu (1c); Cp' = C5Me4SiMe3) with PhSiH3 afforded the mixed hydride/alkyl complexes [Cp'Ln(mu-H)(CH2SiMe3)(THF)](2) (Ln = Y (2a), Dy (2b), Lu (2c)). The overall structure of complexes 2a-c is a C-2-symmetric dimer containing a planar symmetric Ln(2)H(2) core at the center of the molecule. Deprotonation of ArOH (Ar = C6H2-Bu-t(2)-2,6-Me-4) by the metal alkyl group of 2a-c led to formation of the mixed hydride/aryloxide derivatives [Cp'Ln(mu-H)(OAr)](2) (Ln = Y (3a), Dy (3b), Lu (3c)), which adopt the dimeric structure through hydride bridges with trans-accommodated terminal aryloxide groups.
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In the presence of NH3-Ag+-NH3, the calix[4]arenes can be induced into dimeric nanocapsules, which can be used as building units constructing a 3D molecular architecture with the appropriate secondary ligands and metal ions.
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Herein, one water-soluble functionalized ionic liquid (IL), 1-butyl-3-methylimidazolium dodecanesulfonate (BAS), was designed, investigated and successfully applied to microchip micellar electrokinetic chromatography (MEKC) construction. It possessed the properties of both IL and surfactant. A fairly stable pH value similar to 7.4, which was fit to pH values of general biological buffers, was nicely placed at the optimum concentration of 20 mM BAS solution. While applying BAS solution as running buffer in poly(dimethylsiloxane) (PDMS) microfluidic systems, significantly enhanced electroosmotic flow (8-fold) and resolutions between analytes were obtained than that using other supporting electrolytes or surfactants.