磺化聚乙烯中空纤维离子交换膜渗透汽化分离异丙醇/水混合液研究

离子交换膜作为醇/水和其他有机水溶液的渗透汽化分离膜有很好的选择性^[1-3]。其中尤以磺化聚乙烯离子交换膜最为显著。用磺化聚乙烯离子膜分离恒沸组成的异丙醇/水和乙醇/水(85:15wt%)混合物^[4]、近恒沸组成的二氧六环/水混合物^[5],透过物中水含量大于99%,而且保持了较高的渗透通量。但上述实验均使用的平板型膜,大型平板膜组件的加工制造昂贵而困难,况且膜在分离运行过程中会随料液浓度的变化发生溶胀与收缩,使固定的平面膜起皱在收缩时又可能被拉破。为了提高单位组件内的膜面积(中空纤维组件的膜装填密度为平板式的60-100倍),发展中空纤维型膜及其组件势在必行。本文首次报道磺化聚乙烯中空纤维阳离子交换膜对异丙醇/水的渗透汽化性能。     

醇/水混合物在磺化聚乙烯中空纤维阴离子交换膜中的渗透汽化

通过对聚乙烯中空纤维光化学氯磺化反应,继而胺化和季胺化,制备了磺化聚乙烯中空纤维阴离子交换膜。以恒沸组成的异丙醇/水和85wt%乙醇/水为料液,测定了不同抗衡离子膜的渗透汽化性能。表明:该膜有极高的选择性,分离系数和渗透通量与抗衡离子密切相关,对卤素离子,α_W/A大小次序为I~->Br~->Cl~-;通量大小次序与之相反。三种抗衡离子膜的平衡吸收实验表明,该阴离子膜的选择渗透性不仅与醇水在膜中的溶解度有关,而且取决于平均扩散系数。     

磺化聚乙烯离子交换膜渗透汽化分离二氧六环／水混合物研究

本文用非均相光化学氯磷化反应制得了亲水的耐有机溶剂耐酸碱的磺化聚乙烯离子交换膜．膜截面离子基因密度与反应程度有关．该膜对近恒沸组成的二氧六环／水混合液显示出很高的渗透汽化分离系数和透过速率．研究了对离子、离子交换容量、料液浓度和温度对分离性能的影响．通过膜内水合离子形成“水通道”模型讨论了渗透机理．膜内离子基团密度估计及水的表观渗透活化能的大小支持“水通道”的存在．     

用聚丙烯磺酸盐膜渗透蒸发分离乙醇／水混合物的研究

通过聚丙烯膜进行非均相氯磺化反应,对其产物进一步水解和离子交换,得到具有不同反离子的聚丙烯磺酸盐膜。应用渗透蒸发法进行乙醇/水混合物的分离。研究了反离子的种类、膜离子交换容量、混合液的组成、膜厚度和实验温度等对该分离膜的分离特性(即分离系数和通量)的影响。并用X射线衍射法和扫描电子显微镜研究了膜结构和形态。     

氯磺化聚乙烯结构和性能研究Ⅰ.氯磺化反应及其对晶体结构的影响

氯磺化聚乙烯水解后是一种性能特异的离子交换膜。本文研究了低密度及高密度聚乙烯中空纤维氯磺化反应时间与交换容量之间的关系,并用红外光谱及广角X射线衍射法测定了氯磺化反应对聚乙烯晶体结构的影响。结果表明,氯磺化反应主要发生在聚乙烯的非晶区,最大交换容量及反应速度均与非晶区含量有关。反应对晶粒表面也有一定程度的侵蚀作用,随着交换容量的增加,结晶度下降,晶粒度减小。低密度及高密度聚乙烯的变化趋势相似,但前者比后者变化更显著。     

中空纤维催化膜反应器中环戊二烯的选择加氢反应

将聚乙烯吡咯烷酮（ＰＶＰ）负载钯催化剂（ＰＶＰ－Ｐｄ）镶嵌到三种醋酸纤维（ＣＡ）中空膜（ＣＡ－Ｉ，ＣＡ－Ⅱ，ＣＡ－Ⅲ）内制各中空纤维催化膜，并进一步制成催化膜反应器，在４０℃和０．１ＭＰａ的反应条件下，在催化膜反应器中进行了环戊二烯的选择加氢反应，考察了具有不同氢气渗透率的醋酸纤维丝组成的三种膜反应器对反应的转化率及选择性的影响，并在此基础上考察了各种反应参数对反应的影响，ＣＡ中空纤维催化膜对环戊     

PVA／PEG共混渗透蒸发膜的盐水分离机理研究

以聚乙烯醇（ＰＶＡ）和聚乙二醇（ＰＥＧ）共混,甲醛交联制备亲水性高分子膜,用于渗适蒸发过程进行海水脱盐。ＰＥＧ的引入使盐－水分离成为可能, 到钠的引入使膜的分离通量明显提高。通过溶用蔗、ＰＥＧ水溶液的粘度和膜形态分析等方法对ＰＶＡ－ＰＥＧ体系的高分子网络结构和膜中相分离作了研究,发现了膜结构与渗透蒸发脱盐性能的基本关系。影响膜分离的因素除了化学亲合性之外,主要是膜的溶胀性和微相分离程度。ＰＥＧ的作     

聚环氧乙烷（PEO）／壳聚糖（CS）共混膜的醇－水渗透蒸发性能研究

研究了ＥｔＯＨ－Ｈ２Ｏ，ｎ－ＰｒＯＨ－Ｈ２Ｏ，ｉ－ＰｒＯＨ－Ｈ２Ｏ体系在ＣＳ膜和ＰＥＯ／ＣＳ共混膜中的渗透蒸发性能。讨论了料液温度、料液浓度、共混膜组成对分离性能的影响，结果发现ＰＥＯ的掺入能大大提高ｃｓ膜的渗透通量；而分离因子下降。同时从膜材料的聚集态结构出发对相关的渗透蒸发行为进行了讨论。对于ＰＥＯ／ＣＳ共混膜，膜内自由体积的大小是影响分离性能的主要因素，小分子在膜中的渗透蒸发行为主要是由扩散过程控制的。本文还研究了ＰＥＯ的掺入对壳聚塘膜强度的影响以及利用ＤＳＣ谱研究ＰＥＯ掺入后壳聚糖膜聚集态结构的变化。     

聚环氧乙烷（PEO）／壳聚糖（CS）共混膜的醇—水渗透蒸发性能研究

研究了ＥｔＯＨ－Ｈ２Ｏ，ｎ－ＰｒＯＨ－Ｈ２Ｏ，ｉ－ＰｒＯｈ－Ｈ２Ｏ体系在ＣＳ膜和ＰＥＯ／ＣＳ共混膜中的渗透蒸发性能。讨论了料液温度、料液浓度、共混膜组成对分离性能的影响，结果发现ＰＥＯ的掺入能大大提高ＣＳ膜的渗透通量，而分离因子下降。同时从膜材料的聚集态结构出发对相关的渗透蒸发行为进行了讨论。对于ＰＥＯ／ＣＳ共混膜，膜内自由体积的大小是影响分离性能的主要因素，小分子在膜中的渗透蒸发行全为主要是由扩     

添加PVP和涂覆聚合物对PAN基中空纤维炭膜性能的影响

研究了用ＰＡＮ基中空纤维膜为基质制备气体分离用中空纤维炭膜的过程。考察了添加剂ＰＶＰ对炭膜的Ｈ２，Ｎ２气体渗透速率，分离系九和柔韧性的影响。同时，研究了用丙烯腈共聚物对中空纤维炭膜涂覆改性后Ｈ２，Ｎ２气体的渗透速率和分离系数。     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

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.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.