非表面活性剂模板法合成甲基丙烯酰氧丙基修饰的有机/无机杂化中孔材料

1992年具六角规则孔道及窄孔径分布的ＭＣＭ 41中孔分子筛合成的报道[1,2 ] 激起了中孔材料的研究热潮 .近 3年来 ,用巯基[3 ,4 ] ,苯基[5] ,氨丙基[6] ,烯丙基[7] 和乙烯基[8] 等有机基团修饰的有机 无机杂化中孔材料的研究倍受瞩目 .这些杂化中孔材料兼有无机相的光学特性、热稳定性和有机相的韧性、反应性 ,可以进一步功能化应用于催化、金属离子提取[9] 及涂料[10 ] 等领域 .1 998年 ,Ｗｅｉ等[11] 首次采用葡萄糖、麦芽糖等非表面活性剂有机分子为模板 (或成孔剂 ) ,通过溶胶 凝胶过程合成出高比表面积、孔径可调且孔径分布窄的二氧化…     

苯及苯磺酸基官能化的中孔分子筛的合成及催化应用

近年来 ,通过对介孔分子筛 (如 MCM,HMS,MSU-X)结构及组成的化学“裁剪”,制备具有特定结构和表面性质的催化材料成为该领域的研究热点之一 [1～ 5] .许多文献报道了 MCM-4 1的有机官能化中孔材料的制备技术 [5～ 8] ,并将其应用于有机合成反应 ,取得了较好的结果 [7,8] .其中 MSU-X介孔分子筛结构具有三维排列“Worm-like”孔道特征 ,有利于物料传输 ;相对于 MCM-4 1分子筛在合成方面具有以中性表面活性剂作模板剂且模板剂容易去除等诸多优点[9] .本文采用非离子表面活性剂 C11— 15H2 3— 31(CH2 CH2 O) 9H(AEO9)为模板剂 ,…     

有机官能化MSU-x孔分子筛的界面特征

MSU- x是自 M41S系列介孔分子筛问世以来所合成的另一类新型介孔分子筛材料 ,它具有三维立体交叉排列的 " worm- like"孔道结构特征及采用中性模板剂、廉价无毒等诸多合成优点 [1～ 4],有着潜在的应用价值 .为了改善纯硅的介孔材料的表面和孔道性质 ,扩大其应用领域 ,除了在骨架引入金属离子或在其孔道中负载催化活性物质外 ,对介孔材料进行有机官能化制备无机-有机杂化材料改善其骨架和孔道性质是当前研究的热点之一 [5].正是由于活性有机基团的存在 ,使得这些材料可直接用于催化反应 ,或作为中间介质成为其它络合离子的主体 .由于有机基…     

Nb-MCM-41硅基中孔分子筛的合成与表征

ＭＣＭ４１中孔分子筛在催化、吸附分离、离子交换以及无机材料等领域具有较高的工程应用与研究价值．近年来,在催化应用方面,将具有一定催化活性的过渡金属元素如Ｔｉ［１］、Ｚｒ［２］、Ｍｏ［３］、Ｖ［４］、Ｆｅ［５］、Ｍｎ［６］、Ｗ［７］等以高分散的形态嵌入分子筛骨架结构中,得到了许多具有催化氧化性能的新型催化剂．这些新型催化剂已在石油加工、精细化学品和有机中间体的制备等方面显示出良好的应用前景［８］．铌的化合物是目前引人注目的一种新型催化材料,因为具有酸活性中心及氧化还原功能,已应用于烯烃齐聚［９］…     

水玻璃为原料在开放体系中快速合成介孔材料MCM-41

自从 M41 S系列硅基介孔分子筛被人工合成以来[1,2 ] ,有关分子筛的合成、性能、形成机理、结构和应用等方面的研究报道不断出现[3～ 5] .目前 ,由有机 -无机离子经分子水平的自组装结合而产生介孔材料的合成机理主要归结于在合成过程中表面活性剂的模板效应 ,如液晶模板机理[1,2 ] 、棒状自组装模型[6 ] 、电荷匹配机理[7] 、层状折皱模型[8] 和使用非离子表面活性剂合成介孔材料等效应[9] .本文以水玻璃作为硅源 ,以十六烷基三甲基溴化铵 (CTAB)阳离子表面活性剂为模板剂 ,在温和条件下 ,采用开放体系合成出具有 MCM-4 1结构特点的介…     

含钛中孔分子筛Ti-MSU的合成和表征

作为一种具有新型结构的功能材料、中孔分子筛以其具有较大的孔径、很大的比表面积和优良的吸附性能等诸多优点而引起了催化、吸附分离、无机合成及材料科学等许多领域内研究者的广泛关注.M41S[1]、HMS[2]、SBA-n[3]及MSU[4]等一系列的中孔分子筛相继问世.在这几类中孔分子筛中,MSU系列中孔分子筛因使用价廉、无毒、可生物降解的聚氧乙烯基醚类非离子型表面活性剂作为模板剂而对于当今世界人们普遍关注的环境友好化学具有尤为重要的意义.     

新型隔层材料LB交替多层膜的二次谐波研究

有机光学非线性材料在光计算和光通讯领域中有着非常广泛的应用前景［1，2］．非中心对称结构是二阶非线性光学器件的基本要求之一，对于有机两亲光学活性分子而言，使用能够在分子尺度上实现有序组装的Langmuir－Blodgett（LB）技术，可以制备具有稳定而非中心对称结构的多层膜．一般说来，Y型结构的多层膜比X型或Z型更稳定．然而，由单一材料组成的Y型LB多层膜只能形成中心对称结构，因而对宏观二阶非线性极化率X（2）没有贡献．为了解决稳定性与非中心对称性的矛盾，我们可以将光学非线性活性材料（如半花菁染料）与非活性隔层材料…     

介孔分子筛SBA-15中α-胰凝乳蛋白酶组装及催化活性研究

介孔分子筛由于规则孔道或笼的存在 ,使其具有择形催化作用、高比表面积和强吸附性能 ,其孔道中可组装多种物质而改变其理化性能 .Thomas等 [1] 在介孔 Si O2 上接枝金属茂复合物 .白妮 [2 ] 和张雪峥 [3 ] 等分别将脂溶性金属酞菁衍生物和杂多酸封装在介孔分子筛中 ,得到的组装体催化性能优良 .近年来由于不断合成出 MCM- 41 [4 ] 和 SBA- 1 5 [5] 等孔径较大的介孔分子筛 ,使在介孔材料孔道中组装生物大分子成为可能 .Yen等 [6] 将细胞色素 c组装到孔道中 ,并使酶的稳定性得到提高 ,而α-胰凝乳蛋白酶 (Mr=2 5 0 0 0 ,分子动力学直径…     

硅基分子筛及其在精细化学品合成中的应用*

本文综述了沸石分子筛及中孔硅基材料在合成方面的最新进展,总结了这类分子筛材料在精细化学品合成中的应用及取得的成果,详细介绍了中孔分子筛的表面改性尤其是有机－无机杂化分子筛的合成、性质、特点及其作为催化剂在有机合成反应中的应用。     

复合Fe2O3纳米粒子的高分子微球的结构表征

近年来，复合有机、无机粒子的高分子微球及其特殊性质越来越引起人们的兴趣与关注［1］．获得有机、无机复合微球的方法很多，如在无机粒子存在下的乳液或无皂乳液聚会[2，3]，通过可聚合的表面活性剂在粒子表面形成胶囊化层[4]以及共沉淀法等[5]．这些无机粒子包括氧化钛、氧化铁、氧化铝及氧化硅等．Haga等[6]增发现包覆在聚合物粒子中的CdS与其本体的光电性质不同；单分散的聚合物微球可以在基片上被组装成二维乃至三维有序的结构[7]．这为信息存储、立体印刷等领域提供了新途径．因此，将无机粒子与聚合物复合成为功能化粒子是一项有…     

Facile synthesis methodology and characterization studies of silica-decorated hybridized anisotropic nanotubes and nanosheets

Carbonaceous nanomaterials and their derivatives have been inspired tremendous enthusiasm in the scientific community. They have been excogitated as the encouraging attributes and the qualified dispersed phase to develop multi-functional composites. Particularly, graphene and carbon nanotube (anisotropic fillers) have gained substantial research interest owing to their promising characteristics. This highlights an innovative technique to synthesize hybridized nanotube and nanosheet. Initially, parent materials have been synthesized: The pristine CNT has been modified by acid mixture solution, and reduced graphene oxide has been prepared by chemical reduction method. Henceforth, the self-assembly in situ sol–gel technique has been endorsed here. The synthesized nanohybrids have been characterized by different spectroscopic techniques: FTIR, Raman, UV, and XPS to confirm the attachment of multifunctionalities; meanwhile, the composition and stability have been investigated from XRD and TGA plots. The magnitude of surface charge and particle size distribution have been evaluated for the parent and hybridized products; further, morphology of all the samples has been authenticated from FESEM and TEM.     

Synthesis and electronic absorption and fluorescence of 2-arylbenzothiazole derivatives

A series of new 2-arylbenzothiazoles have been prepared in high yields by Jacobson's cyclization condensation of 2-aminobenzenethiol with benzoyl chloride or benzaldehyde derivatives under three different routes. These compounds have been fully characterized by EA, IR, NMR and MS. The electronic absorption and fluorescence of these compounds have been systematically investigated for the first time. The relationships between their photophysical properties and structures have been discussed. The alteration of absorption and emission wavelengths can be elucidated by Hammett's substituent constants.     

Determination of pyrethroids and their degradation productds in indoor air and on surfaces by HRGC-ECD and HRGC-MS(NCI)

Air and surface samples taken following indoor applications of natural pyrethrins and pyrethroids have been analyzed by HRGC-ECD and HRGC-MS using negative chemical ionization (NCI). It has been found that pyrethroids persist on surfaces as long as sixty hours after application. Primary pyrethroid degradation products have been characterized by mass spectrometry; their identities and route of formation by ozonolysis have been verified by degradation studies and NMR.     

Preparation and testing for homogeneity of spiked strawberry and cabbage candidate reference materials

Strawberry and cabbage candidate reference materials (RMs) have been prepared by our laboratory during 1992–1993. Fresh materials have been homogenized and spiked with known concentrations of pesticides representing compounds commonly used for strawberries and cabbages. The candidate RMs have been then freeze-dried, homogenized, bottled under a stream of nitrogen and stored frozen at –20°C. Homogeneity and stability of the candidate RMs have been studied during the storage period. Homogeneity of the candidate RMs for 5 g samples has been within 10%. Homogeneity and stability studies have been carried out using the conventional multiresidue method of Luke et al. [1]. Instrumental analysis have been performed by gas chromatography mass spectrometry (GC-MS) employing selected ion monitoring (SIM).     

Structure and properties of perimidine and its derivatives

The electronic absorption spectra, luminescence spectra, and vibrational spectra of perimidine and its derivatives have been studied. On the basis of the dipole moments and vibrational spectra, the conformations of 2-(o-hydroxyphenyl)perimidine and 2-(o-hydroxyphenyl)perimidine and 2-(o-methoxyphenyl)perimidine, which are stabilized by intramolecular hydrogen bonds, have been established. The electronic configurations of the perimidines in the ground and first excited states have been calculated by Hückel's MO method. The results have been compared with data on the reactivity and electronic absorption spectra of the perimidines.     

3-芳氧基-6-取代哒嗪的合成及其除草活性

合成了系列3-芳氧基-6-取代哒嗪类化合物.化合物结构经¹HNMR、元素分析、IR和MS确证.生物活性测试结果表明,该类化合物具有很好的除草活性,讨论了其结构与除草活性的关系.     

Synthesis and properties of novel photochromic bisthienylethenes containing imidazole and imidazolium derivatives

A series of bisthienylethenes containing imidazole and imidazolium derivatives have been prepared and the products have been characterized by means of NMR and MS.Their photochromic and fluorescent switch properties have been investigated by UV–vis absorption spectra and fluorescence spectra.The fluorescent emissions of these kinds of photochromic compounds can be simply modulated by varying the imidazole groups,which shows that these compounds may have potential application in the design of fluorescent photochromic materials.     

ClO与ClO自由基反应机理及电子密度拓扑分析

利用密度泛函理论对ClO与ClO自由基反应机理进行了深入理论探讨,在B3LYP/6-311＋＋G（3df）水平上对该反应体系的反应物、中间体、过渡态及产物进行了几何构型优化,对反应通道进行了IRC(内禀反应坐标）路径解析,计算了沿各反应通道的能垒和离解能,并进行了零点能校正.从量子拓扑学的角度,对反应通道IRC途径上一些重要点进行了电子密度拓扑分析,讨论了反应过程中化学键的断裂、生成以及键的变化规律,找到了反应途径的能量过渡态和结构过渡态.     

Preparation and testing of stationary phases and modified capillaries for affinity chromatography and affinity capillary electrophoresis of pepsin

Three stationary phases have been prepared for affinity liquid chromatography isolation and separation of porcine and human pepsin. The phases contain 3,5-diiodo-L-tyrosine (DIT) bound to the supports HEMA BIO VS, HEMA BIO E and EPOXY TOYOPEARL. These phases have been tested on a model sample of porcine pepsin A and applied to human pepsin. Fractions have been collected and the chymase activity determined in selected analyses. For affinity CE, capillaries have been prepared by modifying the wall with 3-aminopropyltriethoxysilane, followed either by direct binding of DIT, or by binding L-tyrosine that was subsequently iodated. The dissociation constant K(d) has been determined for the pepsin-DIT complex from the changes in the electrophoretic mobilities.     

Microcrystals of polydiacetylene derivatives and their linear and nonlinear optical properties

Organic microcrystals which are expected to have interesting and fascinating physical properties were fabricated by a reprecipitation method as aqueous dispersions. Many kinds of organic compounds have been microcrystallized by this convenient method. The size control has been extensively investigated for a polydiacetylene and succeeded in the range from several tens of nanometers to several micrometers by adjusting the temperature and concentration. Linear optical properties of these well-defined polydiacetylene microcrystals have been investigated and interesting size and temperature dependences of excitonic absorption are demonstrated. Nonlinear optical (NLO) properties of polydiacetylene microcrystals have also been evaluated by means of a Z-scan technique, and an extremely high nonlinear refractive index at the resonant wavelength was shown.