自组装铝/氧化铜和铝/氧化铁及其性能评估

本文分别采用模板法制备氧化铜纳米花, 水热法制备氧化铁纳米环, 并自组装制备了铝-氧化铜和铝-氧化铁2种铝热剂。自组装增大了异相材料之间的接触, 分别使得铝-氧化铜的反应放热量和压力由523 J·g^-1、1 858 kPa增加至1 069 J·g^-1、 4 389 kPa;铝-氧化铁的反应放热量和压力由1 448 J·g^-1、749 kPa增加至2 039 J·g^-1、2 280 kPa。两种铝热剂的放热量和压力差别较大, 且铝-氧化铜的静电感度高于大多数含能材料, 铝-氧化铁的撞击感度特别低, 显示出不同的应用特点。     

自组装铝/氧化铜和铝/氧化铁及其性能评估

本文分别采用模板法制备氧化铜纳米花,水热法制备氧化铁纳米环,并自组装制备了铝/氧化铜和铝/氧化铁2种铝热剂。自组装增大了异相材料之间的接触,分别使得铝/氧化铜的反应放热量和压力由523 J.g-1、1 858 kPa增加至1 069 J.g-1、4 389kPa;铝/氧化铁的反应放热量和压力由1 448 J.g-1、749 kPa增加至2 039 J.g-1、2 280 kPa。两种铝热剂的放热量和压力差别较大,且铝/氧化铜的静电感度高于大多数含能材料,铝/氧化铁的撞击感度特别低,显示出不同的应用特点。     

Synthesis of aluminum oxide nanoparticles in an aqueous ammonium-formaldehyde solution

A method of synthesis of the organic-inorganic nanocomposite consisting of a paraformaldehyde matrix and aluminum oxide nanoparticles is developed. Spontaneous dispersion of the composite in water at various component ratios makes it possible to prepare a sol or gel of hydrated aluminum oxide. No changes in the oxide particle dimensions are observed during storage of the composite.     

Properties and structural features of nanodisperse powder fillers

Comparative characteristics of polymer materials based on epoxy binder reinforced by disperse and fiber fillers are given. The structural features of nanopowders of aluminum oxide and copper are considered with the aim to use them as nanofillers of polymer materials. The dependence of structures of nanopowders under investigation on the change of their specific surface is shown. The fractional composition of aluminum oxide is analyzed, and particle sizes of fine and coarse fractions are found.     

Use of Mother Liquor from Fluorplastic Production for Preparing Composite Coatings

The composition and properties of mother liquor from production of F4D fluoroplastic were studied. Nickel-fluoroplastic cathodic and aluminum oxide-fluoroplastic anodic composite coatings were prepared. Aluminum oxide-fluoroplastic composite coatings were obtained by thermal treatment of aluminum oxide coatings impregnated with the mother liquor.     

Synthesis and Electrosurface Properties of One- and Two-Component Nanostructures

One- and two-component (titanium and aluminum oxides) oxide nanostructures are synthesized by molecular layer-by-layer deposition from the gas phase onto silicon oxide and boehmite substrates. Two-component nanostructures are prepared by the consecutive deposition of nanolayers of aluminum and titanium oxides onto a dispersed silica substrate. Electrosurface properties of thus-prepared samples are studied and compared. It is shown that the positions of the isoelectric point and the point of zero charge of a 5TiO₂/5Al₂O₃/SiO₂ composite sample are governed by an outer titanium oxide nanolayer and are similar to those of bulk titanium oxide and a nanostructured film of titanium oxide deposited onto an aluminum hydroxide substrate.__________Translated from Kolloidnyi Zhurnal, Vol. 67, No. 4, 2005, pp. 469–474.Original Russian Text Copyright © 2005 by Bogdanova, Ermakova, Chikhachev, Sidorova, Aleksandrov, Savina.     

Modification of siloxane coatings with boron and aluminum compounds

Modification of siloxane coatings of protective materials with boron (boric acid, boric anhydride, triethyl borate) and aluminum (aluminum butylate, oxide, hydroxide) compounds was studied with the aim to enhance the fireproofing and physicomechanical properties of the materials.     

Dependence of physicomechanical properties of a nickel-cobalt-aluminum oxide composite electrolytic coating on the dispersity of the alloying component

Effect of the dispersity of aluminum oxide on the microhardness, wear, internal stresses, and porosity of nickel-cobalt-aluminum oxide composite electrolytic coatings deposited from a chloride electrolyte and the dependence of the content of aluminum oxide in the coating on the agitation rate and working duration of the electrolyte were studied.     

Physicochemical Principles of the Synthesis of Porous Composite Materials through the Hydrothermal Oxidation of Aluminum Powder

The main versions of the synthesis of a new class of porous cermet materials such as Al₂O₃/Al, MO_x/Al₂O₃/Al, and M¹/MO_x/Al₂O₃/Al and ceramic composites on their basis were analyzed. These ceramic composites were prepared through the stage of the hydrothermal oxidation of aluminum powder and were designed for catalytic and adsorption processes. Equations that express the dependence of the apparent density of the resulting composite on the density of the initial powder mixture, on the concentration of the powdered active component, and on the conversion of aluminum are given. It was found that the formal kinetics of aluminum oxidation with water at 100°C can be described by the Kolmogorov-Erofeev equation. The results were compared with data obtained in an autoclave at higher temperatures and steam pressures. The synthesis parameters that affect the total pore volume and the specific surface area of aluminum oxide obtained from aluminum powder were determined. For the case of the transfer of soluble components from an autoclave to a press mold, the molar coefficients of this process were calculated. The texture peculiarities of composites were analyzed. The texture exhibited a polymodal character with developed micropore, mesopore, and ultramacropore structures, which are responsible for the high permeability of granulated composites. Factors affecting the mechanical properties of metal ceramics were studied. The catalysts and products of composite materials were exemplified.     

镁铝复合氧化物载体的制备与性质研究

以硝酸镁和硝酸铝为原料,用氨水溶液作为pH调节剂,采用共沉淀法制备了镁铝复合氧化物载体,研究了制备过程中镁铝比、pH调节剂种类、水解过程pH值的大小、反应温度、焙烧温度及回流晶化温度对复合氧化物载体理化性质的影响。并以RFCC汽油加氢脱硫为探针反应,考察了以镁铝复合氧化物为载体的催化剂选择性加氢脱硫性能。实验结果表明,在镁铝分子比为10、反应温度为80℃、pH值为9.5条件下制备的镁铝复合氧化物载体具有适宜的比表面积和均匀的孔分布,且晶型较完整,结晶度高。以该复合氧化物为载体制备的催化剂具有良好的RFCC汽油选择性加氢脱硫反应性能。     

Composite materials based on acetylated wood and aluminum and its compounds

The possibility of preparing new composite materials from acetylated wood and aluminum, aluminum chloride, and aluminum hydroxide as mineral fillers was examined.     

Corrosion and electrochemical behavior of water glass coatings embedded with graphite/titanium oxide on 2A12 aluminum alloy

Journal of Solid State Electrochemistry - Graphite/titanium oxide composite anti-corrosion coatings with five proportions of graphite were applied on the surface of aluminum alloy. The surface...     

Zerovalent metal polymer composites. III. Metallization of metal oxide surfaces with the aid of metallized functional polymer microdispersions

The adsorption of poly[N-(m- and p-vinylbenzyl)-N,N,N-trimethylammonium tetrachloropal-ladate] complex on inorganic oxide surfaces followed by reduction of the palladium salt to form a catalytically active zerovalent metal polymer composite dispersed on the oxide surface and further deposition of transition metals, e.g., nickel, cobalt, and copper, by “additive” or “subtractive” deposition from electroless plating solutions is described. γ-Ferric oxide was used as a template for such intermetallic replacement reactions, providing materials with controlled amounts of metal. Multimetallic catalysts based on aluminum oxide, zinc oxide, lanthanum oxide, magnesium oxide, and silica were prepared. Iron oxide modified by subtractive deposition of rhodium and iridium on nickel-clad iron oxide were evaluated in Fischer–Tropsch carbonylation reactions leading from synthesis gas to alkanols.     

Thermophysical properties of polypropylene/aluminum composites

This article is dedicated to the study of the thermal parameters of composite materials. A nonlinear least‐squares criterion is used on experimental transfer functions to identify the thermal conductivity and the diffusivity of aluminum‐polymer composite materials. The density measurements were achieved to deduce the specific heat and thereafter they were compared to values given by differential scanning calorimetry measurement. The thermal parameters of the composite material polypropylene/aluminum were investigated for the two different types of aluminum filler sizes. The experimental data were compared with several theoretical thermal conductivity prediction models. It was found that both the Agari and Bruggeman models provide a good estimation for thermal conductivity. The experimental values of both thermal conductivity and diffusivity have shown a better heat transport for the composite filled with large particles. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 722–732, 2004     

金属氧化物@金属有机骨架复合材料研究进展

金属有机骨架(Metal-Organic Framework,MOF)复合材料是一种新型功能性材料,其中金属氧化物@MOF复合材料因结合了金属氧化物和MOFs的许多特性而受到人们的广泛关注,成为近年来MOFs材料研究的一个重要方向。本文综述了金属氧化物@MOF复合材料制备方法的研究进展,主要包括外延生长法、气相沉积法、模板法等,并分析了它们各自的优缺点;概述了金属氧化物@MOF复合材料在催化、传感、生物医药、吸附与分离方面的具体应用性能,以及在电化学研究领域的潜在应用;并提出今后金属氧化物@MOF复合材料研究的主要方向是开发简单高效的制备方法、选取新功能性金属氧化物以及探索复合材料的其它新型结构,以拓展其在工业上的应用。     

Porous Al2O3/Al Metal Ceramics Prepared by the Oxidation of Aluminum Powder under Hydrothermal Conditions Followed by Thermal Dehydration: II. Composition and Microtexture of the Composites

The microtexture of Al₂O₃/Al composites with different oxide contents formed in the hydrothermal treatment of aluminum followed by thermal decomposition of boehmite is examined by a set of adsorption and structural analysis techniques. Two main types of alumina microtexture are found: relatively loose agglomerates of amorphous particles and highly ordered aggregates of well-crystallized primary blocks of a larger size, the fraction of which increases with the oxide content of the composite leads to an increase in the fraction of micropores and a decrease in the fraction of mesopores. The mechanism of thermal decomposition of boehmite prepared by the hydrothermal oxidation of aluminum is refined.     

氧化石墨烯-海藻酸钠-壳聚糖复合支架的制备及表征

通过冷冻干燥技术, 将不同量的氧化石墨烯与海藻酸钠和壳聚糖复合, 构建复合支架材料. 研究了不同的氧化石墨烯含量(质量分数0, 0.3%, 0.5%, 0.7%, 1%)对支架材料微观结构、 孔隙率、 溶胀比、 体外降解性能、 机械性能及生物相容性的影响, 以确定复合支架中最佳氧化石墨烯含量. 研究结果表明, 复合材料呈固态海绵状结构, 具有一定的形态可塑性; 扫描电子显微镜观察发现, 各组支架均为三维网状结构, 随着氧化石墨烯含量的增加, 孔隙尺寸逐渐降低, 孔壁厚度增加, 孔隙尺寸在140~240 μm之间; 随氧化石墨烯含量的增加, 复合支架溶胀比和体外降解速率逐渐降低, 而机械强度明显增强; 体外细胞毒性显示, 当氧化石墨烯质量分数为0.3%时, 细胞存活率最高, 而当氧化石墨烯含量增高时, 细胞活性会被明显抑制, 造成细胞死亡. 因此, 氧化石墨烯在复合支架中最佳含量为0.3%.     

Interactions of hydrosiloxane and vinylsiloxane groups with aluminum oxide surfaces

Silicone-based materials often contain vinylsiloxane and hydrosiloxane groups for cross-linking by a radical or addition reaction. Such functional groups can influence the interactions with fillers or with surfaces of substrates when used as adhesives. This work examined how these functional groups interact with aluminum oxide surfaces. For this purpose, aluminum oxide powders with large surface areas of 150 m²/g and different acid-base properties were examined. Siloxanes were applied as thin layers to mainly obtain information from the interphase by vibrational spectroscopy. It was observed that vinyl groups show low interactions with aluminum oxide surfaces even at elevated temperatures. In contrast to this, hydrosiloxanes undergo strong interactions and reactions with aluminum oxides already at room temperature. Activated Si─H species were observed as an intermediate state. On the one hand, interactions and reactions might contribute to adhesion, but on the other hand, the cross-linking reaction can be influenced near the surface, leading to lower mechanical strength.     

一步阳极氧化法制备超亲水氧化铝

本文应用一步阳极氧化法在铝表面制作纳米粗糙结构的超亲水表面.考察控槽压、控电流及氧化时间对氧化铝表面超亲水性的影响.测试表明,控电流法更有利于制作超亲水表面,增大电流密度可缩短氧化时间,该法可制作稳定性好、机械强度高的超亲水氧化铝表面,富有潜在的应用价值.