甲壳素对碱性橙Ⅱ染料的吸附性能研究

研究了天然高分子甲壳素对碱性橙Ⅱ染料的吸附性能。确定吸附时的pH,进行了等温吸附、吸附时间和选择性吸附探究。结果表明,溶液中只有碱性橙Ⅱ时,溶液pH3.0时,吸附效果最佳;甲壳素的吸附容量大于35.23μg/mg;在10min内,甲壳素对碱性橙Ⅱ的吸附量达到80%;当溶液中同时存在柠檬黄、日落黄和碱性橙Ⅱ时,溶液pH 10.0,甲壳素对碱性橙Ⅱ有选择性吸附。甲壳素可以用作碱性橙Ⅱ的前处理吸附材料。     

Ag/TiO2复合材料的制备及其对碘离子的吸附研究

利用水解法制备了具有刺状表面结构的球形二氧化钛基体材料,并采用紫外光解法获得了均匀负载的Ag/TiO2材料。利用扫描电子显微镜(SEM)、色散谱(EDS)、傅里叶变换红外光谱仪(FT-IR)和BET等技术手段对材料的结构、形貌、组成成分及比表面积进行了分析表征。开展了Ag/TiO2复合材料对溶液中碘离子的吸附实验研究,考察并讨论了pH值以及共存离子(Cl-、F-、NO3-、SO42-和CO32-)对吸附的影响,结果表明,Ag/TiO2复合材料具有耐酸性强、吸附选择性高、吸附容量大(207mg/g)等特性。     

磷酸化黄原胶/氧化石墨烯的合成及其对铀的选择性吸附

以氧化石墨烯(GO)为基体,黄原胶(XG)为交联剂,磷酸(P)为修饰剂制备了磷酸功能化黄原胶/氧化石墨烯凝胶(P-XG/GO),并应用于铀的选择性吸附。扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、Zeta电势分析等技术表明GO的交联和磷酸化成功。系统研究了溶液pH值、铀初始浓度、吸附时间和温度等因素的影响,得到了适宜吸附条件。吸附数据用Langmuir等温线模型拟合良好,最大吸附能力为495.05 mg/g。与准一级动力学模型相比,准二级动力学模型更好地拟合了吸附过程。     

一种偕胺肟基纤维材料对模拟盐湖水中铀的吸附研究

本文采用预辐射接枝法在7 L固液接枝反应釜中批量制备了偕胺肟(AO)基的超高分子量聚乙烯(UHMWPE-g-(PAO-co-PAA))纤维吸附材料,用红外光谱和扫描电子显微镜表征了材料的功能基团和表观形貌,研究了该材料在模拟盐湖水中对铀酰离子的吸附行为,并考察了溶液矿化度(TDS)、铀酰离子初始浓度等因素对材料吸附行为的影响.在TDS、溶液pH 8.1和铀酰初始浓度与西藏达则错盐湖相当的模拟盐湖体系中,AO含量为6.0 mmol g~(-1)的材料在28 d后对铀的吸附量高达8.29 mg g~(-1).铀酰离子的吸附量随TDS增加而有所降低,在TDS相当于海水10倍的pH 8.1模拟盐湖水中,铀的吸附量仍然达到6.63 mg g~(-1).材料对铀酰离子的吸附量随其初始浓度的增加而增大,在pH 8.1的模拟盐湖水中当铀浓度由187增加到1639μg L~(-1),其吸附量由4.54增加到17.48 mg g~(-1).结果表明,UHMWPE-g-(PAO-co-PAA)纤维材料在盐湖体系铀的提取中具有很好的应用前景.     

聚苯胺/凹凸棒石黏土纳米纤维复合材料对溶液中痕量Cr(Ⅵ)的吸附性能

采用原位聚合法合成了盐酸掺杂聚苯胺/凹凸棒石黏土(PANI/ATP)纳米纤维复合材料.研究了它对含痕量Cr(Ⅵ)废水的吸附,考察了物料配比、投料质量、吸附时间、吸附温度和pH值对其吸附性能的影响.结果表明,复合材料中的物料配比为m(An):m(ATP)=2:1,用暈为0.4 g,50 min时对Cr(Ⅵ)的吸附量达到99.8%,符合Langmuir等温吸附方程.该复合材料充分发挥了有机和无机吸附材料的协同作用,具有成本低、再生性能良好的特点.     

海藻酸钠固定化桔青霉微球对铀的吸附研究

以桔青霉(PC)作为对照,研究了铀溶液的pH值、吸附时间对海藻酸钠固定化微球(SAIPC)吸附性能的影响,吸附铀的最佳pH为6,7h基本达到吸附平衡。在308K,铀浓度为50μg/mL,pH值为6.0,SAIPC和PC分别在7h,5h达到吸附平衡,它们的吸附容量分别达256和116mg/g。对吸附动力学模型和吸附等温模型进行了分析,SAIPC对铀离子的吸附动力学模型较好地符合了准二级动力学方程,吸附等温线符合Freundlich和Langmuir吸附模型。结果表明:SAIPC是一种具有良好应用前景的,可望在工业中应用的生物吸附剂。     

聚苯胺/凹凸棒石纳米纤维复合材料对溶液中痕量Cr(VI)的吸附性能

采用原位聚合法合成了盐酸掺杂聚苯胺/凹凸棒石黏土(PANI/ATP)纳米纤维复合材料。 研究了它对含痕量Cr(Ⅵ)废水的吸附,考察了物料配比、投料质量、吸附时间、吸附温度和pH值对其吸附性能的影响。 结果表明,复合材料中的物料配比为m(An)∶m(ATP)=2∶1,用量为0.4 g,50 min时对Cr(Ⅵ)的吸附量达到99.8%,符合Langmuir等温吸附方程。 该复合材料充分发挥了有机和无机吸附材料的协同作用,具有成本低、再生性能良好的特点。     

聚苯胺改性Mxene复合材料对U(VI)的高效富集及机理研究

采用原位聚合法合成新型PANI/Ti₃C₂T_x有机无机复合纳米材料,并应用于对U（VI）的吸附去除研究.实验结果表明：整个吸附过程受溶液pH和离子强度影响较大,在pH=5.0,室温条件下PANI/Ti₃C₂T_x对U（VI）表现出较高的吸附容量（102.8 mg/g）,这一数值远远高于原始Ti₃C₂T_x对U（VI）的饱和吸附量（36.6 mg/g）.此外,结合傅立叶变换红外光谱（Fourier transform infrared spectrometry,FTIR）和X射线光电子能谱（X-ray photoelectron spectroscopy,XPS）的分析结果表明PANI/Ti₃C₂T_x中含氧官能团和氨基基团与U（VI）发生络合作用,从而大大提高了其吸附性能.基于此研究,PANI/Ti₃C₂T_x可作为具有前景的复合材料应用于含U（VI）废水的净化中.     

SK—C—02吸附剂在头孢菌素C提炼工艺中的应用

本文研究以SK-C-02苯乙烯型大孔吸附剂,从发酵滤液中提取头孢菌素C的工艺条件,包括溶液pH、流速、吸附柱高径北、解吸剂以及该吸附剂的吸附选择性与吸附能力的稳定性。结果表明SK—C—02于酸性条件下吸附,用少量低浓度的有机溶媒就能解吸完全,吸附解吸收率达到90％以上,而且对头抱菌素C和脱乙酰头孢菌素具有良好的分离能力。     

乙二胺硅胶复合材料对Zn2+的吸附特性

以γ-氯丙基三氯硅烷为偶联剂,将乙二胺偶合接枝在硅胶表面,合成对锌离子具有吸附作用的乙二胺硅胶复合材料（EDA/SiO2）,考察了Zn2+溶液pH值、初始浓度、吸附温度和吸附时间等因素对复合材料吸附性能的影响。 结果表明,在研究的溶液浓度及温度范围内,Zn2+溶液pH值对EDA/SiO2的吸附量影响显著,吸附的最佳pH值范围在3.0~5.5;Zn2+的吸附平衡数据符合Langmuir吸附模型,热力学数据显示,EDA/SiO2对Zn2+的吸附行为为一吸热且自发进行的过程,升高温度有利于吸附,并对此吸附行为作了解释;吸附动力学数据可用拟二级吸附动力学方程描述,得到的吸附速率常数与溶液初始浓度有关。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

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.