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以自然沉积的聚苯乙烯(PS)胶体晶体为模板,分别以正硅酸乙酯(TEOS)的醇盐溶液和溶胶溶液为前驱体对PS模板进行填充,通过煅烧除去模板,得到了三维有序大孔(3DOM) SiO2材料.由SEM照片观察发现,当以TEOS的醇盐溶液为前驱体时,获得的3DOM SiO2结构不易控制,缺陷较多.而以TEOS的溶胶溶液为前驱体时获得的3DOM SiO2结构良好,孔径大小均匀,排列整齐,可以看成是PS模板的逆复制,说明前驱体溶液的选择对3DOMSiO2材料的微观结构有显著的影响.XRD分析显示,制备的3DOM SiO2孔壁为无定形结构. 相似文献
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用聚苯乙烯微球模板组装有序多孔氧化锌薄膜 总被引:3,自引:0,他引:3
在洁净的玻璃基片上通过浸提法组装了有序的聚苯乙烯微球(polystyrene spheres,PS)阵列模板.将PS模板再用浸提法垂直浸渍到ZnO溶胶中,在毛细管力的作用下ZnO溶胶进入到微球的间隙中形成凝胶,最后经煅烧除去PS模板而得到多孔ZnO薄膜.模板的反射光谱证实其堆积方式为面心立方结构.用扫描电镜观察了ZnO薄膜的表面形貌.用X射线衍射和紫外/可见光分光光度计对薄膜的性能进行了表征.结果表明:溶胶的浓度和PS模板在溶胶中的浸渍时间对薄膜的形貌有显著的影响,多孔薄膜孔径较微球直径收缩约30%.得到的ZnO薄膜经500℃煅烧后为六方纤锌矿结构,在波长大于550nm后其光谱透过率可达80%以上,禁带宽度约为3.22eV. 相似文献
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采用无皂乳液聚合方法自制的单分散聚苯乙烯(PS)微球乳液为原料,并以PS微球自组装制备了有序胶体晶体模板("蛋白石"),采用溶胶-凝胶模板法制备了三维有序大孔TiO2微球("反蛋白石"),其孔呈六边形,孔径分布均一,约为200 nm,运用SEM,XRD对其形貌特征及晶型进行表征。结果表明,采用表面含有羧基的单分散聚苯乙烯微球及高的硅油粘度制得的模板有序度高;控制煅烧温度可以改变有序大孔TiO2微球的晶型,当煅烧温度为500℃时,其晶型为锐钛型,当煅烧温度为700℃时,其晶型则为金红石型。 相似文献
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以苯乙烯为单体,采用分散聚合法合成粒径不同且单分散性良好的聚苯乙烯微球.将1.5 μm聚苯乙烯微球排列在图案化聚二甲基硅氧烷模具(PDMS mold)中,以此为模板,经过浸渍SiC陶瓷前驱体(聚碳硅烷)、紫外固化和高温焙烧过程,成功制备了二维有序大孔SiC陶瓷阵列.扫描电镜(SEM)照片表明二维有序大孔SiC形貌受聚苯乙烯微球模板调控.通过改变聚碳硅烷涂层的厚度,能够进一步调控二维有序大孔SiC的孔径. 相似文献
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以静电纺丝法制备的聚乙烯吡咯烷酮(PVP)纤维为模板,以非水解溶胶-凝胶法制备的Al2O3溶胶为浸渍液,利用模板浸渍技术制备出Al2O3凝胶-PVP复合纤维,再经1 000℃煅烧制备出γ-Al2O3纤维。借助X射线衍射和扫描电镜研究了浸渍溶胶浓度、浸渍时间及浸渍次数对γ-Al2O3纤维物相组成及形貌的影响。结果表明:当Al2O3溶胶中铝离子浓度为0.1 mol/L、浸渍时间为30 s、浸渍1次时,合成的γ-Al2O3纤维表面平滑,连续性好,纤维直径达到0.22μm。 相似文献
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以CMK-3为硬模板,通过浇铸方法制备介孔固溶体NixMg1-xO。考察了前驱体溶液的浓度、溶剂、灌制方法、灌制次数和模板脱除温度等因素,对合成产物物理性质的影响。结果表明,以浓度为0.8mol.L-1的硝酸盐乙醇溶液作为前驱体,超声波处理下灌制3次,以及在脱除模板的过程中,事先在650℃下Ar气环境中预处理待脱模板样品,之后于650℃高温焙烧,可得到具有介孔特性的NixMg1-xO固溶体。还原介孔固溶体NixMg1-xO所得的Ni/NixMg1-xO催化剂,与浸渍法、共沉淀法制备的Ni/MgO,Ni/NiO-MgO,Ni/MgO(介孔MgO载体)催化剂相比,在催化乙醇转化制氢中,具有最高的催化活性。 相似文献
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Macroporous silica (MS) and macro/mesoporous silica (MMS) were prepared by spray drying a polystyrene (PS) latex sol containing a silica source, followed by calcination. As a silica source, 3-aminopropyl triethoxysilane (APS) was used for MS while either silica sol (SS) or tetraethoxyothosilicate using P123 templating (P123-TEOS) was used for MMS. Spray drying and calcination could also take place in a once-through aerosol reactor. The transformation of the silicon alkoxides to silica and decomposition of PS occurred at similar temperatures. Therefore, for APS-originated MS, the metal additives such as silver and nickel were required to accelerate the former. In addition, the nickel was well dispersed in the silica matrix during calcination even at 800 °C, in turn to thermally stabilize the porous structures. The wall-preforming additives were unnecessary for PS/SS and PS/P123-TEOS, since the SS drying and P123 templating, respectively, took place at lower temperature than PS decomposition. The porosities of all the porous silica prepared ranged from 0.54 to 0.57, which were close to the volume fraction of PS in the PS-alkoxides mixture solidified right after spray drying. 相似文献
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《Journal of the European Ceramic Society》2019,39(11):3353-3363
A single-step and all-colloidal deposition method to fabricate yttrium-stabilized zirconia (YSZ)-inverse photonic glasses with 3 μm pores was developed. The process is based on electrostatic attraction and repulsion in suspension, controlled by surface charge of polystyrene (PS) microspheres and YSZ nanoparticles, used as pore templates and matrix material, respectively. The pH was used as a tool to change surface charges and particle-particle interactions. Photonic glass films with 3 μm pores yielded broadband omnidirectional reflection over the wavelengths of 1–5 μm, relevant for thermal radiation at temperatures around 1200 °C. These highly porous materials maintained their structural stability and reflectance after being annealed at 1200 °C for 120 h. 相似文献
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Highly ordered porous NiO film is prepared by self-assembled monolayer polystyrene sphere template-assisted electrodeposition. The as-prepared NiO film shows an ordered hexagonal close-packed bowel-like array that is made up of macrobowls with about 500 nm in diameter. The electrochromic properties of NiO film are investigated in an aqueous alkaline electrolyte (0.1 M KOH) by means of transmittance, cyclic voltammetry and chronoamperometry measurements. The ordered porous NiO film prepared with PS sphere template exhibits a noticeable electrochromism with reversible color changes from transparent to dark brown, and presents quite good transmittance modulation with a variation of transmittance up to 76% at 550 nm. The ordered porous NiO film also shows high coloration efficiency (41 cm2 C−1), fast switching speed (3 s and 6 s) and good cycling performance, compared with the dense NiO film prepared without PS sphere template. The improvements of electrochromic performances are attributed to the highly porous morphology, which shortens the ion diffusion paths and provides bigger surface area. 相似文献
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Anna Lashtabeg John L. Bradley Guillaume Vives John Drennan 《Ceramics International》2010,36(2):653-659
The microstructure of the electrodes, in particular the anode, is of vast importance in the present stage of Solid Oxide Fuel Cell (SOFC) development. Templating methods provide well ordered, inverse opal, macroporous structures for small quantities of powder, scaling up the procedure to produce commercial quantities of powder remains a challenge. This study examined different synthesis conditions for producing larger amounts of high quality YSZ and NiO/YSZ electrodes using the templating technique and the effects of these on microstructure. The study revealed that as the quantity of the polystyrene (PS) spheres for the template is increased the microstructure quality is reduced, due to increasing difficulty in homogeneous permeation of the template. Thus the optimisation of the ratio of PS spheres to powder is of great importance and in this study was found to be around 2:1, however the addition of NiO has additional effects on the microstructure. 相似文献
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采用少皂乳液聚合法成功制备了单分散的聚苯乙烯微球,以微球自组装后的聚苯乙烯胶体晶体为大孔模板,铝溶胶为前驱体填充模板,干燥焙烧除去模板后制备了氧化铝载体。用激光粒度仪、扫描电镜、X射线衍射和氮气吸脱附对聚苯乙烯胶体晶体和氧化铝载体进行了表征。结果表明:少皂乳液聚合法制备的聚苯乙烯微球具有粒径较小(100~350 nm)、单分散性好(0.005)、收率高(约80%)等优点;自组装的胶体晶体呈规则有序排列,微球表面光滑洁净,并以此为模板成功制备了具有三维有序结构的、大孔孔径可调的氧化铝材料。 相似文献
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Anna Lashtabeg John Drennan Ruth Knibbe John L. Bradley Gao Qing Lu 《Microporous and mesoporous materials》2009,117(1-2):395-401
Yttria Stabilised Zirconia (YSZ) is commonly used as an oxygen sensor and an oxygen pump in automotive and industrial applications, and is a choice electrolyte for Solid Oxide Fuel Cell (SOFC) technology. YSZ is also a major component of the SOFC electrodes, and is commonly mixed with 50% volume NiO to create a Ni/YSZ cermet anode. In both the adsorption and fuel cell applications homogeneous control of the porosity of YZS is important. Templating methods provide well ordered macroporous structures and have been used to prepare ordered, macroporous YSZ from metal nitrate precursors using polystyrene spheres of 1 μm as templates. Ordered three-dimensional structures were synthesised and the effects of sintering temperatures of 650–1400 °C on pore size, particle size and pore wall thickness were examined. Ordered porosity was maintained at all temperatures, though some structural degradation and sintering was observed at 1400 °C. This study demonstrated that templated porosity is maintained well above the conventional sintering temperature of the electrodes, and higher than previous studies reported. The stability of these structures at high temperatures makes this fabrication technique a promising alternative to conventional methods of synthesising porous materials. 相似文献
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Hollow spheres of nickel oxide (NiO) and silver, gold, and platinum nanoparticle loaded NiO composites were successfully produced by using polystyrene (PS) latexes as hard template. Due to the presence of tertiary amine based diblock copolymer stabilizer on the surface of PS, the tertiary amine functional groups provided homogene deposition of nickel hydroxide, and then the precursor NiO salt production on the surface of PS latexes with a controlled precipitation technique. Then, NiO and NiO/metal NP hollow spheres were produced by calcination at 600 °C. Thermogravimetric analysis indicated that the amounts of NiO and NiO-composite after calcination were in the range of 21.1–29.7 wt%. The diameters of metal oxide spheres were in the range of 2.0–2.7 μm and the shell thickness were in the range of 250–350 nm. These structures had very low densities due to their porous and hollow structures and had outer layers with highly rough surfaces due to formation of nanosheets, which may offer important advantages for catalysis studies. 相似文献
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《Journal of the European Ceramic Society》2007,27(5):2223-2228
Ordered macroporous SnO2 thin films were fabricated by using colloid crystal template of polystyrene (PS) spheres. Efficient dip-drawing method was used in both PS template assembly and the fabrication of porous structure. The PS templates were orderly assembled on clean glass substrates through colloid crystallization of monodisperse PS latex spheres, which were synthesized by an emulsion polymerization technique. The porous SnO2 thin films were prepared through filling SnO2 precursor sol into the spaces among the close-packed PS templates, and then annealing at 500 °C to remove the PS spheres and form SnO2 crystal wall. The forming mechanism of PS templates through dip-drawing method was explained based on three driving forces existing in the assembly processes. The SnO2 sol concentration and PS sphere size had important effects on formation of ordered porous structure The X-ray diffraction (XRD) spectra indicated the thin film was rutile structure and consisted of nanometer grains. The transmittance spectrum showed that optical transmittance kept above 80% beyond the wavelength of 440 nm. Optical band-gap of the porous SnO2 film was 3.68 eV. 相似文献
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Bo Yang Gao Niu Xiu‐Wen Zhou Xu‐Dong Liu Wei He Bin Yu Ye Zhu Wei‐dong Wu 《Polymer Engineering and Science》2015,55(5):1211-1218
Well‐ordered, globally oriented composite fibers with micro/nanowire arrays of polystyrene (PS) fibers embedded in polyethylene (PE) were prepared by an iterative melt co‐drawing and the bundling technique. With section‐cutting of the PE/PS fiber and the dissolution of inner PS, porous PE fibers were obtained. Optical microscopy and scanning electron microscopy (SEM) showed that the distribution of pores were regular hexagonal, the diameters of the pores after the third drawing step were about 175 nm, and the spacings of pores were 1–2 micron. There was good agreement between calculated and experimental values for the pore diameters and spacings. The obtained porous template was used to prepare Cu nanowires by electrochemical deposition. SEM in combination with the energy dispersive X‐ray analysis (EDX) indicated that Cu nanowires were successfully deposited in the pores of the template. Potential applications of this simple and inexpensive fabrication technology were discussed for preparing micro/nanowire arrays with highly controllable geometric parameters. POLYM. ENG. SCI., 55:1211–1218, 2015. © 2014 Society of Plastics Engineers 相似文献