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大面积3D有序介孔二氧化钛薄膜光子晶体制备与性能研究 总被引:3,自引:0,他引:3
介绍了大面积有序反蛋白石结构介孔二氧化钛薄膜光子晶体制备与性能研究的进展.为了保证二氧化钛骨架结构的稳定性和有序度,从而使氧化钛介孔薄膜达到大面积结构均匀,在介孔薄膜制备过程中采用了几种新的工艺方法,其中包括二氧化硅晶体模板的应用和用NaOH溶液代替常用的HF溶液作为模板去除剂.制备的介孔二氧化钛薄膜光子晶体的面积达到厘米尺寸,二氧化钛骨架的填充率达到17.4%,薄膜制备过程中的收缩率<3%.薄膜透射光谱研究结果表明,这种大面积3D有序的反蛋白石结构介孔二氧化钛薄膜具有非常优良的光子带隙特性,有望成为一类具有非常好的发展和应用前景的光子晶体材料. 相似文献
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In this paper, a new type of anionic surfactant containing four carboxylates was synthesized by a four-step synthetic reaction including bromination reaction and primary amide protective reaction. Intermediates and final products of each step in the whole synthetic process were characterized by 1H NMR and MS. Purification of the anionic surfactant was accomplished through combination of recrystallization and silica gel column chromatography. The structure and the critical micelle concentration (CMC) of this surfactant at different temperatures were also investigated. Unlike traditional mono-carboxylate surfactant easy to form lamellar mesostructure, this surfactant has the hexagonal mesophase structure and comparatively low CMC, hopefully to be applied in the preparation of mesoporous metal oxides. 相似文献
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Kartini I Meredith P Zhao XS da Costa JC Lu GQ 《Journal of nanoscience and nanotechnology》2004,4(3):270-274
This article reports a study of the effects of synthesis parameters on the preparation and formation of mesoporous titania nanopowders by employing a two-step sol-gel method. These materials displayed crystalline domains characteristic of anatase. The first step of the process involved the hydrolysis of titanium isopropoxide in a basic aqueous solution mediated by neutral surfactant. The solid product obtained from step 1 was then treated in an acidified ethanol solution containing the same titanium precursor to thicken the pore walls. Low pH and higher loading of the Ti precursor in step 2 produced better mesoporosity and crystallinity of titanium dioxide polymorphs. The resultant powder exhibited a high surface area (73.8 m2/g) and large pore volume (0.17 cm3/g) with uniform mesopores. These materials are envisaged to be used as precursors for mesoporous titania films as a wide band gap semiconductor in dye-sensitized nanocrystalline TiO2 solar cells. 相似文献
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介绍了各样模板及相关介孔制备体系,包含表面活性剂模板制备,非表面活性剂模板制备,其它模板制备及非模板制备。结果显示介孔结构可以很好的提高纳米TiO2的光催化活性,虽然在少数例子中介孔结构对光催化活性产生的影响很小或是没有影响。重点论述了上述研究方法的原理、优缺点和在改变TiO2性能中的应用,以及这些方法相结合所取得的一些研究进展;并指出这些方法在TiO2光催化剂的研究中发挥的重要作用。 相似文献
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Chenyang Wang Shujuan Ma Yinmao Wei Junjie Ou 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(17):2208194
Janus particles are a kind of materials with asymmetric morphology or surface chemical environment. But so far, the preparation of particles with dual asymmetry is still a challenging problem. Hence the cation surfactant hexadecyl trimethyl ammonium bromide and co-surfactant octadecylamine are applied to improve the Pickering emulsion stability, and the micron-sized silica particles are arranged in a single layer at the toluene–water interface through electrostatic interaction. Furthermore, organosilane reagents are added in the preparation process, resulting in the construction of asymmetric hydrophilic or hydrophobic mesoporous precisely onto the micron-sized silica particles surface. The cation surfactant-assisted Pickering emulsion method is simple, effective, and convenience, which can be applied in the synthesis of various dual Janus silica particles for specific applications. 相似文献
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The effect of carbon precursor on the pore size distribution of mesoporous carbon during templating synthesis process 总被引:1,自引:0,他引:1
Wenzhong Shen Xiangping Yang Qingjie Guo Yihong Liu Yanru Song Zhongxiang Han Qinglei Sun Jian Cheng 《Materials Letters》2006,60(29-30):3517-3521
The starch and cyclodextrin were selected as the precursors and the mixture of surfactant and tetraethyl orthosilicate (TEOS) as template to prepare mesoporous carbon. The result showed that a bimodal pore size distribution in mesoporous carbon derived from starch appeared; one was around 3.4 nm and the other ranged from 3.8 to 16.2 nm. However, there existed a concentrated pore size distribution from 3.2 to 4.2 nm in mesoporous carbon derived from cyclodextrin. The different molecular structure of starch and cyclodextrin and their polymerization process in the presence of sulfur acid were responsible for the resulted mesoporous carbon structure; the starch could polymerize by head to head or side by side, but the cycleodextrin was only polymerized by head to head. 相似文献
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Hangrong Chen Jina Yan Zhengqing Ye Liangxia Zhang Jianhua Gao Jianlin Shi Dongsheng Yan 《Journal of Materials Science》2009,44(24):6531-6537
Some typical worm-like mesoporous non-silica oxides, titania, zirconia, and dopants-incorporated zirconia oxides, with homogeneous
nanocrystalline framework and narrow pore-size distribution have been synthesized via a facile process templated from composite
surfactant of a long chain poly block copolymer combined with non-ionic alkyl-PEO surfactant (Brij56) under the hydrothermal
condition. Bi- or even multi-component zirconia-based composites with further addition of other oxide compositions can also
be obtained with well-defined mesoporous structure and nanocrystalline framework. These mesostructured oxides/composite oxides
show high surface area, well-crystallization framework, and high thermal stability. XRD, nitrogen adsorption analysis, TEM,
and EDX were used for the structural characterizations. The use of non-ionic block-copolymer surfactant is believed to be
responsible for the crystallization of mesoporous framework and high thermal stability at high temperature without structural
collapse. 相似文献
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Hyojung Yoon 《Materials Letters》2009,63(23):2047-2050
Mesoporous hollow silica microspheres were prepared by using W/O emulsion consisting of ethanol droplets as a template in edible soybean oil. Ethanol droplets containing ammonia solution were generated by employing ultrasonication in pure soybean oil. The droplets were colloidally stabilized by means of a cationic surfactant, cetyltrimethylammonium bromide (CTAB). Later on, another proportion of soybean oil dissolving tetraethyl orthosilicate (TEOS) was added to the W/O emulsion. The sol-gel reaction of TEOS was achieved only at the interface of the emulsion droplets, resulting in hollow silica microspheres. After washing the resultant with acetone, mesoporous hollow silica microspheres were simply obtained. Throughout this liquid template-based process, mesoporous hollow silica microspheres can be inexpensively synthesized without employing solid templates. 相似文献
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Mesoporous silica was synthesized by modified nonionic organosilicon surfactant under acidic condition for the first time. The XRD patterns, HRTEM image and corresponding BET characterization show that it has ordered 2-D hexagonal pore channel and ultra thick pore wall (about 6 nm). The calcination can result in the vanishment of organic composite and the linkage of the hydrolyzed silica source and the hydrophobic chain (polymethylsiloxane) of the silica-based template. Hence this recombination process tremendously enhances the pore wall of the resulting mesoporous material and causes a certain amount of micropores in the wall. The resulted mesoporous material has high hydrothermal stability due to its ultra thick pore wall and hydrophobic surface. 相似文献
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Core–shell nanoparticles (CSNs) have attracted considerable attention because of their promising applications in a wide range of fields. Recently, substantial efforts have been focused on the development of facile and versatile methods for preparing CSNs with mesoporous SiO2 or TiO2 shells because of their fascinating properties, such as high surface area, large pore channels and high pore volume. This Research News reviews the recent progress in facile, versatile and reproducible approaches which are simply extended from the well‐known Stöber method to construct mesoporous SiO2 and TiO2 shells for uniform multifunctional core–shell nanostructures. Several strategies, including the surfactant‐templating process, the long‐chain organosilane‐assisted approach, the phase transfer assisted surfactant‐templating process, and the kinetics‐controlled coating approach, are discussed. In addition, new trends in this field for the creation of multifunctional CSNs and novel nanostructures are highlighted. 相似文献