Synthesis of 3D ordered porous polystyrene using silica template

A rigid colloidal silica template was formed by self-assembly of the monodispersed silica spheres prepared according to Stober method. The silica template is highly ordered, which was verified by bright color effect due to Bragg diffraction and the results of SEM. The free radical polymerization of styrene was allowed within the interstices of the rigid template to result in the formation of the three-dimensional periodic silica/polystyrene nano-composites. The titled porous polystyrene was prepared by chemical decomposition of the template with concentrated aqueous hydrofluoric acid. Scanning electron microscopy characterization showed that the macroporous polystyrene has ordered arrays of the uniform pores replicated from the template. Moreover, it was found that the morphology of the as-synthesized macroporous polystyrene was greatly affected by the connectivity of the silica spheres treated under different conditions.     

Synthesis of 3-D ordered macroporous silicate using the template formed from monodispersed polystyrene latex

Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional (3-D) ordered macroporous silica material after removing the template by calcination at high temperature. It was indicated that there existed highly ordered packed pores within the whole silica material by SEM morphology observation. It was also found that the pores were interconnected. The pore size could be controlled mainly by varying the particle size of the latex ranging from 10¹ to 10² nm. The formation process of the ordered pores was also preliminarily discussed.     

PMMA胶体晶体模板法制备三维有序大孔TiO_2/SiO_2

以密堆积的聚甲基丙烯酸甲酯微球为模板,用一种预制备的水分散性TiO2纳米晶、正硅酸乙酯、水和乙醇制成混合溶胶,通过一种浸渍-抽滤方法,将混合溶胶充填于模板微球之间的间隙,原位形成凝胶,最终通过焙烧除去模板微球得到三维有序大孔TiO2/SiO2复合氧化物。样品的SEM结果表明,所形成的球形孔大小均匀,孔径在195$5nm,并以六方和四方的有序排列在三维方向上延伸。样品的TEM和XRD表明大孔的孔壁中含有6～7nm的锐钛矿型TiO2纳米晶。     

以PMMA为模板剂制备大孔ZrO2膜的研究

提高陶瓷膜孔隙率是高性能陶瓷膜制备的重要研究方面，有序大孔材料具有很高的孔隙率。以聚甲基丙烯酸甲酯（PMMA）为成孔模板剂，采用抽滤和重力沉积的组装方法制备了对称的大孔ZrO2膜。实验考察了制膜液的合成每件，通过调节模板剂和ZrO2粒子的电性制得了稳定的制膜液。同时用浸浆法在Al2O3多孔支撑体上制备了非对称大孔ZrO2膜。制得的对称大孔ZrO2膜的孔隙率达到了62％。扫描电子显微镜（SEM）照片显示制备出的ZrO2膜孔径均一，孔排列规则，具有很大的孔隙率。     

Template synthesis of 3-D bimodal ordered porous silica

A dual template synthesis combined with a modified bulk sol-gel process was used to prepare the three dimensional bimodal ordered porous silica, in which the macropore wall is mesoporous and both the pores are interconnected. The macropores were replicated from the template of the dried polystyrene colloidal crystal after being removed by calcination at high temperature, whislt the mesopores were achieved by burning off the surfactant in the gel. The ordered morphologies and interconnection of both the macropores and the mesopores were evidenced by the characterizations with SEM and TEM attached with electron diffraction. Nitrogen adsorption results also confirmed the interconnectivity, sizes and their distribution of the two sorts of pores. The effect of surfactant concentration and calcination conditions on mesopore size and its distribution was also investigated.     

Three-dimensional ordered macroporous platinum-based electrode for methanol oxidation

The attractive application of the direct oxidation methanol fuel cell (DMFC) in wide application areas, such as portable energy and stationary power suppliers, stimulates researchers to search for optimal anodic electrocatalysts for the oxidation of methanol. In prac- tical performance, the catalysts are generally dispersed as nanoparticles for conducting supports with high sur- face area for obtaining maximum catalyst utilization. Porous carbon is one of the well-known supports for the dispe…     

三维大孔氮化碳材料的制备及其血液相容性

以粒径640 nm的单分散二氧化硅胶体晶体为模板,由四氯化碳和乙二胺回流加热制备出氮化碳的前驱物;将其填入模板的缝隙中,在氮气中热处理,形成氮化碳/二氧化硅的复合物;用氢氟酸除去二氧化硅模板,制备出三维大孔氮化碳材料. 通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射 (XRD)、选区电子衍射(SAED)、元素分析、红外光谱(FT-IR)、X射线光电子能谱(XPS),对其形貌结构、元素组成、键合状态进行了形貌和结构的表征. 采用部分凝血活酶时间(APTT)、凝血酶原时间(PT)和凝血酶时间(TT)对其体外抗凝血活性作了初步的评价,发现制备的大孔氮化碳对血液不会造成促凝,说明其可能成为一种新的血液相容性材料.     

The template preparation and characterization of three new shapes of titania nanometer-array systems

Nano-structure systems such as nano-structure de- vices and quantum devices have become a hot spot[1] in the materials science. Recently, the synthesis and the preliminary exploration of the properties of novel nano-structures or nanometer constitutional …     

纳米结构TiO_2微孔复合膜涂膜液的研制

用异丙醇钛经溶胶 -凝胶过程制得了二氧化钛粒子溶胶 ,发现是由锐钛矿微晶组成的 ,溶胶中加入添加剂制得涂膜液在多孔AL2 O3 陶瓷支撑体上涂膜 ,可制得完整的复合TiO2 膜。     

羟基磷灰石纳米线的可控制备

用P2O5和Ca(NO3)2作为前驱体溶液，将溶胶—凝胶法与氧化铝模板(AAO)技术相结合，大面积制备出结构均匀、晶相一致、彼此平行且高度有序的羟基磷灰石(HAP)纳米线．结果表明，通过控制制备AAO模板的条件，可达到控制HAP形貌的目的．     

胶体晶体及三维有序多孔材料的制备

以粒径为80～320nm的单分散苯乙烯／苯乙烯磺酸钠共聚微球为原料，采用一种全新而简单的制备高度有序胶体晶体模板的方法，利用静电相互作用、表面张力以及蒸发过程中的离子扩散等作用在液面形成了不合溶剂的高度有序的胶体晶体．将溶胶-凝胶前驱液在毛细效应作用下渗入胶体晶体间隙，待前驱液固化后，经煅烧去除苯乙烯微球，制备出了具有三维有序结构的多孔材料——倒置蛋白石．     

模板组装制备多孔SiO2及其在纳米材料中的应用

采用不同的几何模板 ,通过溶胶 -凝胶过程 ,探索了模板组装制备孔径形状、尺寸大小可控的微孔氧化硅材料 ;讨论了模板组装合成材料的孔径控制 ,并论述了其在纳米材料中的研究及应用前景     

用新型Sol-gel法制备酚基吡啶硼配合物/二氧化硅复合玻璃

利用新型溶胶 凝胶（sol-gel）方法制备一种酚基吡啶硼配合物((dppy)BF)掺杂的二氧化硅复合发光玻璃. 由于加入Li₂CO₃中和了溶胶以及环己烷萃取溶剂, 使材料的制备时间由传统sol-gel方法的几周减少到几天. 用这种方法制备 了无断裂、 低体积收缩的(dppy)BF掺杂的二氧化硅复合发光玻璃. 荧光光谱研究结果表明,复合材料中(dppy)BF的光稳定性得到明显改善, 发光效率明显提高.     

巯基功能化3DOM TiO2-SiO2吸附剂制备及吸附性能研究

 采用胶晶板法,以聚苯乙烯胶晶为膜板,钛酸丁酯和3-巯基-丙基-三甲氧基硅烷为前驱物一步共聚缩合,制备了巯基功能化的3DOM TiO₂-SiO₂有机-无机杂化材料。SEM、EDS和FTIR测试表明,适当控制前驱物比例,可以制得高度有序的巯基功能化三维大孔材料。对重金属汞离子的吸附容量、吸附动力学等测试表明,这种新型材料对汞离子吸附容量高,达到吸附平衡较快,吸附行为符合Freundlich方程,吸附活化能为30 kJ/mol, 扩散系数仅为10^-12～10^-13m²/s,表明吸附过程仍受一定扩散阻力影响。     

溶胶-凝胶技术制备纳米材料的研究进展

溶胶－凝胶技术是制备纳米材料的特殊工艺,工艺简单,易于操作。笔对溶胶－凝胶技术的基本过程、工艺特点进行了分析,从溶胶－凝胶技术在薄膜方面的应用、膜板合成纳米阵列,以及制备纳米复合材料等方面,对溶胶－凝胶技术制备纳米材料的研究状况进行了详尽阐述。     

空心纳米SiO_2为涂层的整体式催化剂的制备及催化性能

整体式催化剂能够解决纳米级催化剂在固定床加氢反应器中应用的缺陷,并进一步提高催化剂的催化性能。采用多次浸涂法制备了以Pd基蛋壳型SiO2纳米催化剂为涂层,铝溶胶为无机粘合剂、堇青石为结构化基体的整体式催化剂,并进一步研究了该整体式催化剂对乙炔选择性加氢反应的催化性能。研究结果表明:该整体式催化剂具有较高的比表面积和宏观的孔道结构,提高了活性组分的分散性并降低了气体的扩散阻力,在乙炔转化率接近100%时,乙烯选择性可以达到47.5%;此外,该催化剂良好的机械稳定性能,提高了催化加氢性能的稳定性。     

Sol-gel法介孔SiO2膜的制备工艺研究

以正硅酸乙酯为硅源，氨水为催化剂，研究了sol-gel法介孔SiO₂膜的制备工艺，得到了制备SiO₂溶胶的优化工艺条件。发现催化剂氨的浓度是影响SiO₂溶胶质量的关键因素，在影响SiO₂膜制备的众多因素中，溶胶pH值、溶胶浓度和成膜助剂是影响膜制备的关键因素。实验发现，在适宜的条件例如合适的pH值下，溶胶-凝胶-干燥过程具有自适应性，能够自动调节凝胶和干燥速度，从而使凝胶干燥过程中存在的收缩在很大程度上得到减少甚至避免。采用液-液排除法对优化条件下制备的SiO₂膜的孔径分布进行了表征，结果表明，在实验条件下所获得的SiO₂膜的孔径分布在8.8～14.4nm。     

分步催化制备纳米SiO_2减反射膜的性质与结构研究

以正硅酸乙酯和市售硅溶胶为硅源,通过溶胶凝胶法在不同催化条件下制备多孔SiO2减反射膜层,测算了膜层的光学性质及孔隙率,讨论了膜层孔隙构造方式对膜层牢度和耐受性等实用性能的影响.根据讨论结果,采用碱/酸分步催化并引入醇溶性树脂等助剂以改善膜层结构.在光伏玻璃工业辊涂镀膜设备上应用,镀膜光伏玻璃成品的有效透射比达93.7%,且镀膜面外观、膜层牢度及耐受性等皆复合目前相应产品标准的要求.     

正丁胺对Tio2／Sio2气凝胶光催化活性的影响

用溶胶 -凝胶法、超临界干燥技术合成了不同组成的TiO2 /SiO2 气凝胶材料 ,通过模板剂正丁胺调变其孔结构和孔分布 ,利用N2 吸附法、X -射线衍射法和激光拉曼光谱表征了气凝胶的比表面积、孔分布、晶相结构以及TiO2 的分散状态 .用流动法考察了在TiO2 /SiO2 气凝胶上CO光催化氧化反应的活性 ,并讨论了结构调变对提高催化活性的影响 .     

Polymerization within a molecular-scale stereoregular template

Enzymes efficiently synthesize biopolymers by organizing monomer units within regularly structured molecular-scale spaces and exploiting weak non-covalent interactions, such as hydrogen bonds, to control the polymerization process. This 'template' approach is both attractive and challenging for synthetic polymer synthesis, where structurally regulated molecular-scale spaces could in principle provide solid-phase reaction sites for precision polymerization. Previously, free-radical polymerization of methyl methacrylate in solutions containing stereoregular isotactic (it) or syndiotactic (st) poly(methyl methacrylate) (PMMA) has been shown to result in template synthesis of the opposite PMMA based on stereocomplex formation with van der Waals interactions. However, using the structure of a solid to determine the stereochemical structure of a polymer has not been satisfactorily achieved. Here we show that macromolecularly porous ultrathin films, fabricated by a single assembly step, can be used for the highly efficient stereoregular template polymerization of methacrylates through stereocomplex formation. This reaction mould accurately transfers its structural properties of stereoregularity, molecular weight and organization within the template to the new polymer.