有机/无机复合介孔膜的合成及其生物酶吸附行为研究

以正硅酸四乙酯(TEOS)为硅源、三嵌段共聚物(F127)为表面活性剂, 聚碳酸酯膜为硬模板, 并采用抽滤法在聚碳酸酯膜内的亚微米级孔道中组装介孔氧化硅从而制备出有机(聚碳酸酯)/无机(介孔氧化硅)复合介孔膜. 通过扫描电镜、能量分散光谱以及透射电镜等实验表征了该有机/无机复合介孔膜的组成、结构及形貌. 研究结果表明: 通过该方法可以在聚碳酸酯膜内孔道中形成长度为9 μm、直径为200 nm的一维氧化硅棒状材料, 且该棒状材料具有无序蠕虫状和有序体心立方的混合介孔结构, 有序体心立方介孔的平均孔径约为8.5 nm. 另外, 初步考察了该复合介孔膜对生物酶的物理吸附行为, 结果表明其对肌红蛋白酶的单位吸附负载量为5.85 mg/g.     

Au／TS-1@Mesosilica双功能催化材料的制备及其催化丙烯直接环氧化性能

设计制备了一种新型微孔介孔复合核壳结构钛硅分子筛TS-1@Mesosilica（TS-l@Ms）,核为MFI结构钛硅分子筛TS-1,壳层为以非离子表面活性剂P123为模板剂组装形成的介孔氧化硅．壳层氧化硅具有三维蠕虫状孔道结构,有利于微孔和介孔部分的连通及反应物和产物的扩散．通过沉积沉淀法将金纳米粒子负载在壳层介孔孔道,和TS-1中的钛活性中心协同,形成适合于C3H6和H2、O2直接气相环氧化制备环氧丙烷（PO）的双功能催化材料．实验结果表明,Au／TS-1@MS在空速8000mLg-h、温度473K条件下连续反应132h,活性和选择性没有明显下降,丙烯转化率保持在3．7％左右,PO选择性87％以上．     

无电沉积高密度钯金属纳米线阵列

利用介孔氧化硅薄膜作为模板,通过无电沉积路线在介孔薄膜孔道内合成了高密度钯金属纳米线阵列.利用介孔薄膜导向剂的疏水区作为载体,引进钯金属疏水化合物并经热解和还原,得到钯微粒,以此为催化中心引发无电沉积,避免了传统无电沉积复杂的工艺过程.结果表明,纳米线尺寸均一,长径比大于60,完全填充了介孔薄膜的孔道,并可通过介孔模板孔径的选择对纳米线直径加以调控.     

混合表面活性剂模板法合成立方相介孔含钛氧化硅

自1992年Ｍｏｂｉｌ公司的Ｍ41Ｓ系列介孔氧化硅分子筛问世以来[1,2],借助表面活性剂液晶模板方法合成各种孔结构与不同大小孔径的硅基分子筛材料引起了人们的极大兴趣,目前多数工作仍然集中于六方相的介孔分子筛.具有双连续的三维交织立方排列孔道结构的ＭＣＭ48由于其孔道不易堵塞和良好的骨架结构稳定性[3,4],在催化、吸附和与其为载体的制备等方面具有独特的应用价值.但由于液晶模板形成立方相区的范围非常狭窄,相应的分子堆积比对模板剂分子几何结构要求较苛刻,采用单一表面活性剂为模板剂合成时,条件难以掌握,制备ＭＣＭ48十分困难.Ｈ…     

大孔道介孔氧化硅/碳基纳米材料的设计合成与应用

由于具有较大的孔道尺寸、 丰富的化学组成以及广阔的应用前景, 大孔道介孔纳米材料近年来引起了科研工作者的广泛关注. 分别利用复合胶束和无机纳米晶作为结构基元进行可控自组装的软模板法和硬模板法是合成这类大孔道介孔纳米材料最有效的两类方法. 本文总结了一系列基于不同类型软模板或硬模板共组装形成大孔道介孔纳米材料的合成方法和策略, 并讨论了所获得的大孔道介孔纳米材料在催化、 能量转换与存储以及生物医学中的应用. 最后, 对利用新型嵌段聚合物或复杂结构纳米晶合成大孔道介孔纳米材料的前景和挑战进行了展望.     

模板法制备介孔材料的研究进展

从微孔到中孔或介孔材料的制备过程中．离子模板、乳液模板、液晶模板及至细菌模板得到广泛的应用．具有空间规整性的介孔材料就其介观结构所具有的空间群而言，有P6mm，P6 3／mmc，Pm3n，Ia3d；就其介观结构的形态而言．有二维六方，三维六方，双连续立方，La层状相，多层囊泡等．本文对MCM系列，SBA-n系列、MSU系列，以及那些较为单一的硅基品种FMS-16、HMS等的制备体系及其特点进行了综述．对介孔分子筛合成中常用的表面活性剂分子类型进行了归纳．本文针对的是单一表面活性剂作模板的类型，对那些混合型模板则未予详细介绍．     

以SBA-16薄膜/ITO为基底电沉积生长“花状”CdS纳米晶体

在酸性条件下,以导电玻璃(ITO)为基底合成sBA.16分子筛膜.所制备的SBA-16薄膜孔径均匀,具有体心立方结构(属于Im3m空间群).在由CdCl2和Na2S2O3组成的电解液中,调节pH值为2～3.利用直流恒电位电沉积法,调节电位为-0.7 V,沉积时间为50 min,在SBA-16膜/ITO电极表面电沉积生长出"花状"CdS纳米晶体,利用SEM、TEM等技术研究了CdS纳米晶体形貌和结构,同时进行了荧光光谱测试.结果表明,电沉积合成的CdS生长在电极表面而不是生长在介孔孔道中.并能够产生荧光谱峰.     

以SBA-16为模板电沉积生长多孔氧化铁纳米线阵列

采用电化学沉积法以Mn改性的三维体心立方结构的介孔SBA-16膜为模板制备Fe纳米线.沉积Fe后的SBA-16膜以2%HF溶解SiO₂骨架,样品于550℃焙烧4 h.SEM和TEM的研究结果显示,所制备的Fe₂O₃纳米线互相平行,孔径均匀.XRD、电子衍射及HRTEM研究表明Fe₂O₃纳米线具有(多孔)单晶结构.     

混合超分子液晶模板法合成六方介孔相含钛氧化硅

采用混合十六烷基三甲基溴化铵（CTAB）与不同碳链的脂肪胺（CnNH2n＋3, n=8,10,12,14,16）作模板,在四甲基氢氧化胺为碱源的条件下,合成了具有六方介孔结构的含钛氧化硅Ti MCM 41分子筛材料. XRD和TEM测试表明所合成材料具有高度的长程有序结构,样品的N2吸附/脱附等温线表明,高度有序的Ti MCM 41材料展示了毛细凝聚的陡峭台阶和狭窄的介孔孔径分布.对反应物配比中Ti/Si比、脂肪胺碳链长度n对六方介孔相结构的影响进行了研究,实验发现当Ti/Si< 0.15和n< 16时,均可获得具有六方介孔结构的含钛氧化硅Ti MCM 41;而当Ti/Si≥0.15或n >16时,产物将分别发生从六方向无定形态或从六方向层状介孔相结构的转移,从混合表面活性剂的堆积参数对这种相转移现象进行了分析.     

孔径可调的介孔SiO2自支持薄膜的溶剂挥发诱导自组装合成与表征

以十六烷基三甲基溴化铵(CTAB)为模板剂, 正硅酸乙酯为硅源, 在弱酸性条件下利用溶剂挥发诱导自组装(EISA)合成出具有介孔结构的二氧化硅薄膜. 通过控制EISA过程中溶剂挥发的环境, 可在1.4~3.1 nm的范围内调节介孔结构的孔径. 实验表明, 较快的溶剂挥发速率有助于较大孔径的介孔结构生成. 用该方法合成的介孔薄膜具有蠕虫状孔道结构和良好的孔径均一性. 在外观上, 该薄膜具有均匀、透明和无缺陷等特点, 可以自支撑, 并且具有一定的韧性.     

Photoluminescence investigation based on laser heating effect in ZnO-ordered nanostructures

We synthesized ZnO-SiO2 composite opal and ZnO inverse opal by electrodeposition using SiO2-opal template and polystyrene (PS)-opal template, respectively. Compared with compact ZnO nanocrystal film also prepared by electrodeposition, ordered ZnO nanostructures exhibit more significant red-shift and broadening of the UV peak with increasing excitation power, which is due to a stronger local heating effect in ordered ZnO nanostructures. We developed a quantitative analytical method to investigate photoluminescence (PL) of ZnO based on laser heating effects. The experimental data agree well with fitting curves derived from the electron-phonon interaction model. Important parameters, such as electron-phonon coupling strength and thermal activation energy, can be obtained by fitting experimental data. The resonant Raman spectra provide further evidence that the analyses based on laser heating effects are feasible.     

ZnO纳米线阵列的电沉积法制备及表征(英文)

利用直流电沉积方法在多孔氧化铝模板的孔洞中生成锌纳米线,在氧气氛围中,于800°C下氧化2h,将氧化铝中的锌氧化成氧化锌.本研究利用氧气氛围进行锌的氧化,大大提高了传统方法的氧化锌纳米线的制备效率.用场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)和X射线衍射仪(XRD)对其形貌及成分进行表征和分析,结果表明,氧化铝模板的有序孔洞中填充了大尺寸、均匀连续的多晶态氧化锌纳米线.纳米线具有约1000:1的高纵横比,其长度等于氧化铝模板的厚度,直径约为80nm.光致发光(PL)光谱表明,氧化锌纳米线在504nm处有由于氧空位引起的较强蓝绿光发射.这为进一步研究ZnO/AAO组装体发学性质和开发新型功能器件提供了基础.     

柔软的球状和长方体状氧化硅中空结构的制备研究

采用自组装形成的芘纳米结构作为模板,成功地制备了柔软的球状和长方体状氧化硅中空结构.当不同量的芘在十六烷基三甲基溴化铵(CTAB)溶液中自组装时,产生的自组装结构展现出明显的从球状到长方体状的形貌变化.这些结构被用作氧化硅前驱体溶胶-凝胶反应的模板,获得了球状和长方体状氧化硅/芘复合结构.通过乙醇除去模板后,生成了柔软的球状(直径约为400nm)和长方体状(长为0.5—2.5μm)的氧化硅中空结构.这些结果展现了采用有机纳米结构作为模板来合成无机中空结构的优势:合成简便、结构多样以及结构形貌的灵活可控.     

A facile route for shape-selective synthesis of silica nanostructures using poly-L-lysine as template

A facile method for the shape-selective synthesis of silica nanostructures using a reversemicroemulsion -mediated template(RMMT) technique is reported.In this method,positive poly-Llysine (PLL) is selected as template due to its configuration diversity.By adjusting pH and concentration, PLL demonstrates various secondary structures containing random coil,α-helix andβ-sheet,which result in the formation of silica nanorods,silica nanospheres and silica nanotubes in the reversemicroemulsion system,respectively.Thus,the shape-selective synthesis of silica nanostructures might be achieved by using PLL as structural template in the reverse-microemulsion system.     

Electrochemical synthesis of gallium nanowires and macroporous structures in an ionic liquid

The electrochemical synthesis of gallium nanostructures in an ionic liquid is presented. Gallium nanowires and macroporous structures were synthesized by the template-assisted electrodeposition in the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py(1,4)]TFSA) containing GaCl(3) as the precursor. Track-etched polycarbonate membranes with an average pore diameter of 90 nm and a thickness of 21 μm were used as templates for the nanowire synthesis. Ga nanowires with a length of more than 4 μm and an average diameter corresponding to that of the template's pores were easily obtained by this method. Macroporous structures with an average pore diameter of 600 nm were obtained by the electrochemical deposition of Ga inside polystyrene colloidal crystal templates and the subsequent removal of the template by THF. The macroporous deposit showed a granular morphology with smallest grain sizes of about 40 nm and light reflections. The nanostructures of Ga were characterized by HR-SEM and EDX analysis.     

以阴离子表面活性剂/阳离子聚铵复合胶束为模板合成有序介孔二氧化硅

基于静电作用, 阴离子表面活性剂可与阳离子聚铵组装形成复合胶束. 借助阳离子聚铵,复合胶束可以作为模板与硅源协同组装, 形成高度有序的介孔二氧化硅. 本文通过调变不同种类阴离子表面活性剂、合成体系pH值、合成温度及阳离子聚铵和硅源用量等因素, 合成了具有不同介观结构和形貌的介孔二氧化硅. 实验证实阴离子表面活性剂/阳离子聚铵复合胶束模板法是合成介孔二氧化硅的一种通用方法.     

Synthesis and optical properties of ZnO nanostructures in imidazolium-based ionic liquids

Different morphologies of ZnO nanostructures have been synthesized by a simple reflux method, in imidazolium-based ionic liquids and water as a solvent. The effects of ionic liquid as a template with different concentrations and the amount of sodium hydroxide on the morphology and size of nanostructures were investigated. The structural and optical properties of these ZnO particles were studied by using XRD, SEM and UV–Visible. The characteristic results revealed that using different ionic liquids in water not only prevent a drastic increase in the crystallite size of the zinc oxide species but also provide suitable conditions for the oriented growth of primary nanoparticles with nano sheet and nano hallow block. The results show that the longer alkyl chain at position-1 of imidazole ring or using dicationic ionic liquid with a definite concentration cause the more width of nano sheet. A possible mechanism was proposed to explain the formation of ZnO nanostructures with different morphology.     

Making nanometer thick silica glass scaffolds: an experimental approach to learn about size effects in glasses

A convenient method for the synthesis of very well defined porous silica glasses using ionic liquids as templates is presented. Depending on template concentration, these systems form a homologous series of mesoporous systems with diverse shapes, with the pores having constant thickness of about 2.4 nm. These nanostructures allow the analysis of the two-dimensional behavior of glasses, either from a liquid to be embedded in the pore or of the silica glass forming the wall. For the walls, the third reduced dimension can be varied in a systematic fashion. This approach is exemplified by analyzing the static glass structure of 2D-silica by WAXS.     

Vertically Oriented Silica Mesochannels as the Template for Electrodeposition of Polyaniline Nanostructures and Their Electrocatalytic and Electroanalytical Applications

A mesoporous silica film (MSF) with vertically oriented mesochannels on a conductive substrate serves as a hard‐template for electrodeposition of polyaniline (PANI). The PANI nanostructures thus prepared are orderly confined in silica mesochannels, eventually producing a robust hybrid film. The film displays a good electrocatalytic activity toward oxidation of ascorbic acid, and can be used for potentiometric pH sensing with a Nernstian response.     

Facile route to Zn-based II-VI semiconductor spheres, hollow spheres, and core/shell nanocrystals and their optical properties

A convenient chemical conversion method that allows the direct preparation of nanocrystalline ZnE (E = O, S, Se) semiconductor spheres and hollow spheres as well as their core/shell structures is reported. By using monodisperse ZnO nanospheres as a starting reactant and in situ template, ZnS, ZnSe solid and hollow nanospheres, and ZnO/ZnS and ZnO/ZnSe core/shell nanostructures have been obtained through an ultrasound-assisted solution-phase conversion process. The formation mechanism of these nanocrystals is connected with the sonochemical effect of ultrasound irradiation. The photoluminescence and electrogenerated chemiluminescence properties of the as-prepared nanocrystals were investigated.