三维有序SiC空心球的制备及表征

以三维有序多孔碳为模板, 以聚甲基硅烷(PMS)为前驱体, 经过前驱体的渗入、交联和陶瓷转化以及多孔碳模板的烧除, 制备了长程三维有序SiC空心球. 所制备的SiC空心球的外径(135-896 nm)、 球壳厚度(14-79 nm)、 BET比表面积(50.8～5.0 m2/g)及微孔体积(0.265～0.038 cm3/g)受不同孔径的多孔碳模板(150-1 000 nm)或不同前驱体浓度的控制. 所制备的SiC空心球以hcp结构排列成长程三维有序的序列.     

SiO2阶层多孔结构搭建及块体材料制备机理

借助溶胶-凝胶结合相分离和模板法进行了阶层多孔结构的搭建及二氧化硅多孔块体材料的制备,表征了阶层多孔块体的显微结构及孔结构特性,分析了阶层多孔结构的搭建机理。研究结果表明,三嵌段共聚物聚环氧乙烷-聚环氧丙烷-聚环氧乙烷（P123）的加入不仅诱导共混体系发生相分离,调控大孔结构的形成,同时形成球形胶束并作为模板剂进入骨架,而1,3,5-三甲基苯（TMB）的加入使P123形成的胶束膨胀且更加稳定,在骨架上成功引入了球形介孔,骨架中凝胶粒子相互聚集形成微孔,从而搭建贯通大孔-球形介孔-微孔同时分布的阶层多孔结构,并获得相应的多孔块体材料;当正硅酸甲酯（TMOS）：P123：TMB摩尔比为1：0.015：0.353时,多孔块体材料的阶层多孔结构最优,大孔孔径为0.5-1.5 μm,介孔孔径为3-4 nm,显气孔率66.1%,比表面积为616 m²·g^-1。     

利用去湿现象制备图案化的离子刻蚀聚合物保护层

微米和纳米尺度的图案化表面的制备在微电子、光学、生物、化学和材料科学等领域具有重要的科学意义和应用价值 [1～ 3 ] .由于需要复杂昂贵的设备和苛刻的工作环境 ,光刻技术难以广泛应用于微电子以外的领域 ,因此 ,发展简单、便宜、适用于普通实验室 (尤其是化学实验室 )的表面图案化技术已成为一个涉及众多学科领域的课题 .在近年来不断涌现出来的物理、化学和生物的表面图案化技术 [4～ 6]中 ,最具代表性的是由 Whitesides等 [7]发明的以表面具有微观图案的聚二甲基硅氧烷 (PDMS)弹性体作为模具或印章的软光刻技术 .结合溶胶 -凝胶、…     

基于水滴模板法的微纳复合超疏水结构制备的研究

利用粒子辅助水滴模板法的实施获得规则蜂窝状图案化多孔结构模板,并进一步利用聚二甲基硅氧烷(PDMS)复制转移技术获得表面具有微米尺寸蜂窝状突起阵列的反向图案化结构.以这种图案化突起结构作为微米尺寸所提供的微米级粗糙度为基础,设计了2种的简单的二次纳米结构的引入过程,最终实现了微米级阵列和纳米级粗糙度的复合.第一种方法借助银镜反应来实现纳米银结构的化学沉积,最终在PDMS阵列表面获得了致密的纳米银颗粒沉积层,并成功获得了表面接触角达166度的超疏水性质.第二种方法利用了聚电解质/二氧化硅粒子层层静电自组装的方法引入纳米结构,结果在仅仅进行了2个组装循环的条件下即可获得超疏水性质的表面复合结构.通过简单的实验设计试图提供一种基于水滴模板法的微纳复合超疏水结构的普适性制备方法.     

双模板体系中多级结构碳酸钡晶体的控制合成

在用细乳液聚合法制备聚合物微球的基础上,以此聚合物形成的不溶性自组装膜与可溶性的修饰剂聚丙烯酰胺组成的双模板为三维聚合物模板体系,成功完成了多孔、刺球等具有复杂多级结构碳酸钡晶体的制备.实验过程中发现,调节双模板的组成可精确调控碳酸钡晶体的成核与生长.同时,多孔碳酸钡晶体为典型的大孔材料,孔径为103.4 rm,BET...     

生物蛋清蛋白模板合成海绵状大孔无机氧化物

多孔无机材料因可在微加工,催化,生物分离,电子器件的矿化和色谱载体等方面的广泛应用而引起人们极大的兴趣^[1-9],模板技术是制备孔材料最有效的工具之一,以表面活性剂和嵌段共聚物作为模板剂可以合成出结构多样,孔径均一,有序度高的介孔分子筛（2－50nm),大孔无机材料（＞50nm)通常采用以高分子微球和微乳液作模板的方法来合成（^[10],最近,我们利用浓度极高的;盐溶液和聚苯乙烯球作为模板,合成了3D海绵状大孔和介孔复合的氧化硅薄片^[11][,利用电化学等方法合成了具有特殊光阻性质的大孔氧化硅,氧化钛,金属以及合金材料等^[12],利用电化学等方法合成了具有特殊光阻性质的大孔氧化硅,氧化钛,金属以及合成材料等^[12],也有人利用相分离的方法制备无序大孔材料,但该方法一般较复杂,成本也比较昂贵,自然界中的大孔材料如海藻,珊瑚（氧化硅）是通过生物蛋白质为模板在基胞核内形成的,但是生物蛋白的模板作用和形成机理目前还不十分清楚。     

介孔氧化硅膜在多孔陶瓷载体上的组装

采用过滤成膜方式结合溶剂挥发诱导自组装方法在多孔氧化铝中空纤维上制备了介孔氧化硅膜。XRD、TEM和N₂吸附脱附实验结果显示非担载膜具有有序的六方介孔结构。通过对中空纤维担载膜的XRD分析进一步确认介孔氧化硅膜的形成。SEM和EDS线扫描结果显示制备的担载膜表面完整、无缺陷,膜层和载体界面之间结合紧密。在此基础上对介孔膜在多孔陶瓷载体上的形成机理进行了探讨。     

以微凝胶为基质的杂化材料制备及应用研究进展

水凝胶微球即尺寸较小的球形水凝胶,除了凝胶特性外,其特点主要是具有较小的尺寸和球形形貌。由于其网络结构和快速的刺激响应性,使其作为模板制备具有独特性能的杂化材料而备受关注。本文主要从几个方面阐述了以微凝胶为基质制备杂化材料的方法及其应用。包括了磁性金属氧化物-凝胶杂化材料、金属单质-凝胶杂化材料、生物活性-凝胶杂化材料及功能化的球形和膜状杂化材料,最后介绍了本实验室以微凝胶为基质制备表面图案化杂化材料的方法。     

PMMA为模板合成多孔TiO2微米球及紫外光催化性能

以聚甲基丙烯酸甲酯(PMMA)球为模板,用溶剂热法制备了具有多孔结构的TiO2微米球.用扫描电镜、X射线衍射、N2-吸脱附、热重分析对样品进行表征,并通过对亚甲基蓝的紫外光催化降解评价样品的光催化性能.结果表明,样品为单分散的锐钛矿晶型TiO2球形颗粒,其直径在4 μm左右,溶解法去除PMMA模板后得到以微孔为主的多孔TiO2微米球,若再对其进行水热处理,则样品中大部分微孔转变为中孔,得到以中孔为主的多孔TiO2微米球.水热处理后,样品结晶度好,热稳定性高,比表面积为138 m2·g-1,对亚甲基蓝(MB)的光催化降解效果较好,光照40min后降解率达到97.4%.     

基于3D受限自组装构筑中空介孔氧化硅/碳复合微球

发展简单、高效、可控的方法来制备中空介孔微球是介孔材料领域的研究热点.本工作结合嵌段共聚物的三维受限自组装(3D-CSA)和自模板碳化策略,建立了一种构筑中空介孔微球的新方法 .首先,采用乳液-溶剂挥发法实现嵌段共聚物与全氟辛烷(PFO)在3D受限空间的分级组装,获得了核-壳结构微球,其中壳层由微相分离的嵌段共聚物构成.然后,在壳层的连续相选择性地复合氧化硅,既实现了无机框架的负载,又实现了对连续相聚合物链选择性交联.对复合微球进行煅烧处理后,实现了壳层连续相聚合物的选择性碳化,获得了中空介孔氧化硅/碳复合微球.本研究系统地阐述了核-壳型分级结构微球的形成机理和必备条件,研究了氧化硅前驱体添加量和嵌段共聚物分子量对中空介孔氧化硅/碳复合微球形貌的影响,为制备中空介孔微球材料提供了一种简便、可控的方法.     

Macroporous SiC?MoSi2 ceramics from templated hybrid MoCl5–polymethylsilane

A molybdenum‐containing preceramic polymer, MoPMS, was synthesized for the first time by HCl elimination of polymethylsilane (PMS) and MoCl₅ at room temperature in tetrahydrofuran. The insoluble MoPMS prepared was embedded into the void spaces of a silica colloidal crystal template within the pot life of the polymer and successfully transformed to a three‐dimensionally long‐range‐ordered macroporous SiC? MoSi₂ ceramic after pyrolysis at 1400 °C in an argon atmosphere followed by template removal in HF. The bead‐inverse macroporous SiC? MoSi₂ ceramic, with a ceramic yield of about 88%, exhibits high temperature stability, high BET surface area, and semiconducting behavior. In addition, the macroporous SiC? MoSi₂ ceramic was used as a catalyst carrier for platinum–ruthenium coated on the surface of the pores. The preceramic polymer and the ceramic were characterized by IR, thermogravimetric analysis, X‐ray diffraction, scanning and transmission electron microscopy, and BET surface area. Copyright © 2005 John Wiley & Sons, Ltd.     

Fabrication of hollow colloidal crystal cylinders and their inverted polymeric replicas

We fabricated colloidal crystals on a fiber by a dip-coating method. The self-assembly of monodisperse colloidal particles was affected by the curvature of the fiber (the reciprocal of the fiber radius). As the fiber became smaller in diameter, fewer layers of the colloidal spheres were coated for a given lift-up speed. The hollow colloidal crystal cylinders were used as a template for creating macroporous structure having three-dimensionally interconnected air cavities. Specifically, the polymer precursor was infiltrated into the colloidal crystal template and the macroporous polymer structures were obtained after the selective etching of colloidal particles.     

Practical approach for macroporous structure embedded microfluidic system and the catalytic microchemical application

We present a low cost and practical approach to integrate 3D ordered macroporous polyfluoropolyether (PFPE) patterns into a microchannel by a series of porous pattern fabrication processes and subsequent photolithography in a site- and shape-selective manner. The 3D ordered macroporous patterns with high-resolution edges were firstly fabricated by microtransfer molding (μ-TM) of the sacrificial polystyrene (PS) template infiltrated with PFPE as a non-adhesive and solvent-resistant skeletal material. The resulting robust PFPE porous structures with high solvent resistance on a silicon wafer can easily be embedded into the microchannel with the aid of conventional photolithography, leading to a microfluidic system with a built-in microstructure. Moreover, catalytic Pd nanoparticles implanted on the surface of the porous structure were obtained by use of Pd nanoparticle deposited PS spheres, the porous structure embedded channel was utilized to perform a Suzuki coupling reaction.     

Large-scale fabrication of wafer-size colloidal crystals, macroporous polymers and nanocomposites by spin-coating

This paper reports a simple spin-coating technique for rapidly fabricating three types of technologically important materials--colloidal crystal, macroporous polymer, and polymeric nanocomposite, each with high crystalline qualities and wafer-scale sizes. Dispersion of monodisperse silica colloids in triacrylate monomers is spin-coated onto a variety of substrates. Shear-induced ordering and subsequent polymerization lead to the formation of three-dimensionally (3D) ordered colloidal crystals trapped inside a polymer matrix. The thickness of as-synthesized colloidal crystal-polymer nanocomposite is highly uniform and can be controlled simply by changing the spin speed and time. Selective removal of the polymer matrix and silica spheres lead to the formation of large-area colloidal crystals and macroporous polymers, respectively. The wafer-scale process is compatible with standard semiconductor microfabrication, as multiple micrometer-sized patterns can be created simultaneously for potential device applications. Normal-incidence transmission spectra in the visible and near-infrared regions show distinct peaks due to Bragg diffraction from 3D ordered structures. The spin-coating process opens a new route to the fundamental studies of shear-induced crystallization, melting and relaxation.     

Fabrication of macroporous SiC from templated preceramic polymers

Macroporous SiC with a highly ordered pore array was prepared for the first time using low molecular weight SiC preceramic polymers such as polymethylsilane or polycarbosilane by utilizing sacrificial colloidal silica crystalline arrays, as a template which were subsequently etched off after pyrolysis in an argon atmosphere.     

聚苯乙烯胶晶膜及三维有序大孔SiO2膜的制备及表征

采用垂直沉积法组装了三维聚苯乙烯胶晶膜,并用其为模板制备了三维有序大孔（3DOM）SiO2膜．SEM观察表明,制备的胶晶膜和3DOMSiO2膜具有fcc结构,有序性很好．考察乳液浓度对胶晶膜结构的影响表明,浓度越高,胶晶膜越厚,有序性也越高,膜在30层内都能很好的粘附在载玻片上．通过调整前驱物溶液的浓度和滴加方式,可得到表面为球形或孔状的3DOM SiO2膜．     

单分散聚苯乙烯乳胶有序膜在二氧化硅多孔材料制备中的模板作用

自然界中许多物质经千万年发展进化,具有特殊结构,决定了它们具有奇异特性.人们对此过程非常关注,试图了解其结构性能关系,从而实现人工合成,仿生学应此而产生.比如天然蛋白石能呈现出鲜艳颜色,其原因在于单分散二氧化硅微球与具有选择性吸收光的某些金属氧化物微粒形成了有序的超晶格结构[1].为了模拟此过程,人们以单分散二氧化硅或聚苯乙烯微粒形成的胶体晶作为模板,实现蛋白石的人工合成[2].可以说,模板合成技术是制备有序材料的有效手段.本文以单分散聚苯乙烯乳胶室温形成的有序膜为模板,采用快速溶胶凝胶方法,制备了聚苯乙烯/二氧化硅…     

Pore-filling Three-dimensionally Ordered Macroporous Polyimide Composite Proton Conducting Membranes

The silica opal templates were prepared from three silica colloids of different diameters of 230 nm, 500 nm and 1.5 mm by a filtration route. The large-scale stable opal template membranes after sintering the deposited SiO2 opal template can be successfully obtained by optimizing the pH value and NaCl concentration in silica colloidal solutions. The three-dimensionally ordered macroporous(3DOM) polyimide membranes without crack were fabricated by reproducing the structure of silica opal template. We prepared the pore-filling composite proton exchange membranes by filling the 3DOM structure with proton conducting organosilane sol. The result indicates that the composite membranes exhibit higher water uptake than pure filling organosilane gel. The proton conductivity increased with the increasing of pore cell in composite membranes.