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两种有机物改性膨润土对Cu2+和Zn2+的吸附-解吸研究 总被引:1,自引:0,他引:1
选用天然有机物料(猪粪降解液)和有机化学试剂[十六烷基三甲基溴化胺(HDTMA)]对钠基膨润土进行表面改性,比较了膨润土对两类有机物的吸附特性,以及两种有机物改性膨润土对Cu2+、Zn2+吸附-解吸性能的差异。结果表明,膨润土对HDTMA和猪粪降解液是优惠吸附,且前者最大吸附量为382.4mg/g,是后者的4.19倍。HDTMA改性膨润土对Cu2+、Zn2+的最大吸附量均大于猪粪降解液改性膨润土,前者分别为后者的1.12倍(Cu2+)和1.09倍(Zn2+),且两种吸附剂对Cu2+的最大吸附量和吸附速率均大于Zn2+。Zn2+在两种改性膨润土上的解吸率均高于Cu2+,且Cu2+、Zn2+在猪粪改性膨润土上的解吸率均要高于在HDTMA改性膨润土的。两种有机物改性的钠基膨润土对重金属离子具有良好的吸附性能,可以用于含重金属废水的处理和重金属污染土壤的钝化修复,而猪粪降解液改性膨润土是环境友好的重金属钝化剂。 相似文献
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以有机插层剂双十八烷基二甲基氯化铵(DHAC),对新疆夏子街膨润土进行插层改性,制备DHAC改性膨润土。红外光谱(FTIR)分析表明,双烷基阳离子插层进入蒙脱石片层。X射线衍射(XRD)表明,DHAC改性膨润土片层间距为3.772 nm,为改性前的2.07倍,表明改性后蒙脱土片层间距增大。SEM分析观察, DHAC捕层改性后膨润土颗粒更加疏松,蒙脱石颗粒表面有明显的刻蚀痕迹。通过研究改性膨润土的吸附机理分析表明,DHAC改性膨润土在不同温度下的等温吸附模型符合Freundlich模型,且相关性较高。挥发酚在改性膨润土上的吸附焓值为-2.64 kJ/mol,属于物理吸附,且△Gθ<0,说明该吸附为自发的放热过程。室温下DHAC改性膨润土吸附挥发酚的动力学模型遵循Bingham和Langmuir速率方程。 相似文献
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双阳离子复合改性膨润土的吸附性能与构效关系 总被引:4,自引:0,他引:4
膨润土是一种以蒙脱石为主要成分的天然吸附材料. 本文用2-巯基乙胺盐酸盐(MEA)与十六烷基三甲基溴化铵(HDTMA)复合改性内蒙钙基膨润土(IMB), 制得具有特殊结构与性能的吸附材料MEA-HDTMA-IMB. X射线衍射(XRD)、红外光谱(FT-IR)、热分析(TG-DTA)及比表面积(N2-BET)等结构表征表明: 复合改性膨润土的比表面积和层间距显著增大. 吸附研究发现: MEA-HDTMA-IMB能同时有效吸附混合水溶液中的有机物对硝基苯酚和重金属铜. 复合改性膨润土对水中有机物的吸附机理以分配作用为主, 其吸附能力强于用季铵盐阳离子单一改性的有机膨润土HDTMA-IMB; 对水中重金属的吸附主要为络合反应, 其吸附性能与用巯基铵阳离子单一改性的膨润土MEA-IMB相当. 相似文献
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研究了稀土(Ce、Gd和Y)改性丝光沸石用作甲醇胺化催化剂在常压固定床反应器中选择性合成二甲胺的催化性能。结果表明,稀土阳离子交换改性能改善丝光沸石的催化性能。丝光沸石经0.1mol/LCe4+溶液处理,与膨润土成型,再于600℃下焙烧2~3h,这样制得的催化剂在常压400℃时的活性及二甲胺选择性分别达到99.8%和50.3%。此外,详细探讨了不同改性及制备条件对催化剂催化性能及机械强度的影响。 相似文献
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应用碰撞诱导解离(CID)技术研究了电子轰击方法产生的脂肪胺分子离子和化学电离方法产生的质子化脂肪胺分子的碎裂反应。质子化脂肪胺碰撞活化后的主要碎裂通道包括丢失C_XH_(2X)、C_XH_(2X 1)、C_XH_(2X 2)单元及NH_3和生成[C_yH_(2y 1)]及CH_3CH=NH_2~ 离子。脂肪胺分子离子碰撞活化后的主要碎裂通道是丢失C_XH_(2X)、C_XH_(2X 1)及NH_3和生成[C_mH_(2m-1)]~ 、CH_2NH_2~ 及CH_3CHNH_2~ 离子。随着碰撞能的增加,远电荷碎裂反应和电荷诱导碎裂反应之间竞争引起产物离子的的分布发生变化,如[C_mH_(2m-1)]~ 和[C_yH_(2y 1)]~ 离子。自由基机理可以解释质子化脂肪胺分子的远电荷反应。分子内氢抽取可以解释脂肪胺分子离子的碎裂反应。 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献