多孔金属过滤材料研究进展

多孔金属过滤分离材料广泛应用于固体,液体和气体的过滤和分离.总结了多孔金属过滤材料的研究应用现状,介绍了多孔金属过滤材料的制备工艺,分析了多孔金属过滤材料的性能,提出了多孔金属过滤材料的发展方向.     

堇青石质多孔陶瓷的制备与应用现状

概述了堇青石质多孔陶瓷的特点及研究现状,系统介绍了堇青石质多孔陶瓷在催化剂载体材料、过滤分离材料、耐火材料以及电子器件材料等方面的最新研究进展,总结了堇青石质多孔陶瓷的制备方法,并展望了堇青石质多孔陶瓷研究的发展趋势。     

粗中有细 步步精密——烧死结多孔金属膜

在纷纷荟荟的过滤介质当中，烧死结多孔金属以其旧越的综合技术批量标独树一帜。通过高温烧结，金属（粉未、纤维等）颗粒表面间形成钢性金属结构结合，同时又保留一些孔隙，这种结构的元件称作“多孔多属”。与其他材料的过滤元件相比，烧结多孔金属具有众多优势：     

多孔微晶玻璃的制备、性能及用途

多孔微晶玻璃是一种密度小、质量轻、比表面积大、阻尼性能好的新型功能材料。研究了粉末烧结法、整体析晶-酸浸法、溶胶-凝胶法制多孔微晶玻璃的成孔机理和制备过程。分析了多孔微晶玻璃的力学性能和渗透性能。从过滤、保温、载体、分离4个主要方面阐述了多孔微晶玻璃的用途，展望了多孔微晶玻璃的发展趋势及应用前景。     

不对称多孔金属材料的研究进展

不对称多孔金属材料是一种性能优良的新型多孔材料,这种结构实现了现代多孔材料过滤行业的高精度、大流量生产要求,同时良好的力学性能使得不对称多孔金属材料的应用较陶瓷膜的应用更为广泛。本文综述了不对称多孔金属材料研究概况,并就不对称金属多孔材料的发展趋势作了相应预测。     

高孔隙率金属多孔材料的制备技术与应用

高孔隙率金属多孔材料是一种兼具结构和功能材料优点的新型优质金属材料,拥有高孔隙度、高的比表面积、高连通孔隙度、良好的导电导热性等多种优异性能,在生产实践和科技生活中有着广泛的应用。综述了常见的高孔隙率多孔材料的制备方法,并总结了对应方法在制备高孔隙率多孔材料方面的最新研究成果;分析和讨论了部分制备技术的优缺点以及成功制备出高孔隙率多孔材料的关键点和难点;归纳了在制备高孔隙率金属多孔材料时不同制备技术的适用范围和优势;介绍了高孔隙率金属多孔材料在过滤分离、生物医学、电池和催化、吸声降噪、高效热交换等应用领域的研究现状,最后指出制备高孔隙率金属多孔材料现存的问题并对其未来发展趋势进行了展望。     

高性能聚苯硫醚过滤材料研究进展

聚苯硫醚(PPS)过滤材料具有耐热、耐酸碱、对恶劣环境适应性强等特点,广泛应用于高温除尘及热化学品过滤,但其纤维韧性差、高含氧量环境下易氧化的缺点缩短了滤材的使用寿命。研发高性能PSS过滤材料可以降低过滤过程的费用,扩大其适用范围。从提高过滤材料捕集效率、提高材料强度、延长过滤材料使用寿命的角度,介绍了高性能PPS过滤材料的制备方法及研究进展,并对其发展前景进行了展望。     

脱合金法制备纳米多孔金研究进展

纳米多孔金作为一种重要的结构功能材料,在过滤、催化剂载体、传感器、光催化、微流体及分离等方面有着巨大的应用前景。文章综述了纳米多孔金的制备方法。一脱合金法以及最新进展,介绍了脱合金的原理、纳米多孔金的性能以及将来的应用领域     

多孔矿物材料的孔道结构及应用进展

对多孔矿物材料的孔道结构和形态进行了分析,然后对多孔矿物材料的孔道效应和表面荷电效应进行了重点介绍。在对多孔矿物材料的功能属性进行讨论的基础上,对多孔矿物材料在过滤、吸附、离子交换、功能载体、建筑、储氢等方面的应用进展进行了系统分析。在此基础上,对多孔矿物材料的应用方向进行了展望。     

Ti-Al金属间化合物多孔材料的研究进展

Ti-Al金属间化合物多孔材料兼备陶瓷和金属多孔材料的性能优势,为具有很大发展潜力的新型无机多孔材料。目前,对于Ti-Al金属间化合物多孔材料的研究包括以下3个方面:反应合成Ti-Al金属间化合物多孔材料的制备及孔结构形成过程和机理;偏扩散-反应合成-烧结制备的Ti-Al金属间化合物多孔材料的物理、化学性能;偏扩散-反应合成Ti-Al金属间化合物多孔材料的应用及其潜力。Ti-Al金属间化合物多孔材料包括多孔体、多孔膜和多孔纸型膜等多种形式;Ti-Al金属间化合物多孔材料的性能主要包括膨胀特性、孔结构性能、抗环境腐蚀性能及焊接性能;Ti-Al金属间化合物多孔材料的现有应用范围主要包括过程工业中流体介质的过滤分离净化,以及化学工业中复合钯膜的支撑体。     

多孔陶瓷材料的研究进展

多孔陶瓷是一种新型功能材料,由于其具有气孔率高、耐高温、抗化学腐蚀、热稳定性好等优良性能,而被广泛应用于众多领域。本文总结了多孔陶瓷材料的分类方法和性能指标,介绍了多孔陶瓷的制备工艺和特点;并列举了多孔陶瓷在过滤器、催化剂载体、节能隔热材料、吸声材料和生物材料等方面的应用;最后展望了多孔陶瓷材料的发展前景。     

多孔材料抑制瓦斯爆炸传播的实验及机理

利用自行设计加工的断面为30cm×30cm方形爆炸实验管道,对不同参数的金属丝网、泡沫陶瓷材料和多孔泡沫铁镍金属的抑爆效果分别进行了实验研究,结合材料特点,分析了其抑爆机理。实验结果表明,金属丝网、泡沫陶瓷和多孔泡沫铁镍金属对瓦斯爆炸传播均有一定抑制作用,多孔泡沫铁镍金属衰压和阻火效果优于金属丝网和泡沫陶瓷,材料的损坏程度明显降低,对火焰衰减效果增强;测点4,多孔泡沫铁镍金属相比40目40层金属丝网对最大火焰温度的衰减率提高了43.8%,相比Al2O3 7cm大孔泡沫陶瓷提高了34.5%。测点7,多孔泡沫铁镍金属相比40目40层金属丝网体对爆炸超压的衰减率提高了29.9%,相比SiC 5cm大孔泡沫陶瓷提高了22.4%。     

Preparation and properties of a new porous ceramic material used in clean energy field

At high temperature, the oxide redox reactions of ceria can split H₂O and CO₂ to produce H₂ and CO, so porous ceria with high temperature resistance and high specific surface area has an important foreground in clean energy applications. In this work, a reticulated porous ceria ceramic material with interconnected porous structure was prepared by the impregnation technique using organic polyurethane sponges as template. The influences of pretreated sponge, dipping time length, pore size and sintering temperature on the porosity and strength of the porous ceria ceramics were systematically studied. With the increasing sintering temperature, the glass phase occurred and led to an increase in strength, but an decrease in porosity. Eventually, we analyzed the relationships between porosity and strength of these porous materials, aiming to provide theoretical and practical references for its application in clean-energy field.     

Low thermal conductivity and high porosity ZrC and HfC ceramics prepared by in-situ reduction reaction/partial sintering method for ultrahigh temperature applications

Porous ultra-high temperature ceramics(UHTCs) are potential candidates as high-temperature thermal insulation materials. However, high thermal conductivity is the main obstacle to the application of porous UHTCs. In order to address this problem, herein, a new method combining in-situ reaction and partial sintering has been developed for preparing porous Zr C and Hf C with low conductivity. In this process, porous Zr C and Hf C are directly obtained from ZrO_2/C and HfO_2/C green bodies without adding any pore-forming agents. The release of reaction gas can not only increase the porosity but also block the shrinkage. The asprepared porous Zr C and Hf C exhibit homogeneous porous microstructure with grain sizes in the range of 300–600 nm and 200–500 nm, high porosity of 68.74% and 77.82%, low room temperature thermal conductivity of 1.12 and 1.01 W·m~(-1) K~(-1), and compressive strength of 8.28 and 5.51 MPa, respectively.These features render porous Zr C and Hf C promising as light-weight thermal insulation materials for ultrahigh temperature applications. Furthermore, the feasibility of this method has been demonstrated and porous Nb C, Ta C as well as Ti C have been prepared by this method.     

High strength and high porosity YB_2C_2 ceramics prepared by a new high temperature reaction/partial sintering process

Porous ultrahigh temperature ceramics(UHTCs) are potential candidates as reusable thermal protection materials of transpiration cooling system in scramjet engine. However, low strength and low porosity are the main limitations of porous UHTCs. To overcome these problems, herein, a new and simple in-situ reaction/partial sintering process has been developed for preparing high strength and high porosity porous YB_2C_2. In this process, a simple gas-releasing in-situ reaction has been designed, and the formation and escape of gases can block the shrinkage during sintering process, which is favorable to increase the porosity of porous YB_2C_2. In order to demonstrate the advantages of the new method, porous YB_2C_2 ceramics have been fabricated from Y_2O_3, BN and graphite powders for the first time. The as-prepared porous YB_2C_2 ceramics possess high porosity of 57.17%–75.26% and high compressive strength of 9.32–34.78 MPa.The porosity, sintered density, radical shrinkage and compressive strength of porous YB_2C_2 ceramics can be controlled simply by changing the green density. Due to utilization of graphite as the carbon source, the porous YB_2C_2 ceramics show anisotropy in microstructure and mechanical behavior. These features render the porous YB_2C_2 ceramics promising as a thermal-insulating light-weight component for transpiration cooling system.     

无机膜管气体除尘流场分布的数值模拟

先进的多孔无机膜管为高温、高腐蚀烟气净化提供了一种切实可行的新型技术路线,但装置的设计还存在很多急需解决的问题.利用Gambit软件建立了无机膜管二维几何模型,采用FLUENT软件中混合模型对无机膜管过滤瞬间的速度和压力场进行数值模拟.结果表明,通过膜管的压强降分布均匀,并且压强降损失主要发生在膜管的多孔过滤介质中.该模型可以用来分析预报无机膜过滤器内的气体流动情况,并可以为无机膜管收尘装置的优化设计提供理论依据.     

煤气化合成气除尘用过滤器研究进展

当前,世界各国均在研究洁净煤燃烧技术中高温干法除尘技术,其中高温合成气除尘是煤发电和煤化工行业的重要工序。煤气化合成气除尘用过滤器一直都是材料研究者的重要课题之一。综述了国内外对于合成气除尘用过滤器的研究现状,介绍了高温陶瓷过滤器、失效保护过滤系统和烧结金属过滤器的研究进展。为了改善陶瓷过滤器的固有缺点,提高其可靠性和稳定性,10年来各国材料研究者作了大量的工作,成绩突出。而对金属除尘过滤器的研究除了要求符合合成气工况使用要求外,降低制备成本也是一项重要内容。     

Porous high entropy (Zr0.2Hf0.2Ti0.2Nb0.2Ta0.2)B2: A novel strategy towards making ultrahigh temperature ceramics thermal insulating

Transition metal diborides based ultrahigh temperature ceramics (UHTCs) are characterized by high melting point, high strength and hardness, and high electrical and thermal conductivity. The high thermal conductivity arises from both electronic and phonon contributions. Thus electronic and phonon contributions must be controlled simultaneously in reducing the thermal conductivity of transition metal diborides. In high entropy (HE) materials, both electrons and phonons are scattered such that the thermal conductivity can significantly be reduced, which opens a new window to design novel insulating materials. Inspired by the high entropy effect, porous HE (Zr_0.2Hf_0.2Nb_0.2Ta_0.2Ti_0.2)B₂ is designed in this work as a new thermal insulting ultrahigh temperature material and is synthesized by an in-situ thermal borocarbon reduction/partial sintering process. The porous HE (Zr_0.2Hf_0.2Nb_0.2Ta_0.2Ti_0.2)B₂ possesses high porosity of 75.67%, pore size of 0.3–1.2 μm, homogeneous microstructure with small grain size of 400–800 nm, which results in low room temperature thermal diffusivity and thermal conductivity of 0.74 mm² s⁻¹ and 0.51 W m⁻¹ K⁻¹, respectively. In addition, it exhibits high compressive strength of 3.93 MPa. The combination of these properties indicates that exploring porous high entropy ceramics such as porous HE (Zr_0.2Hf_0.2Nb_0.2Ta_0.2Ti_0.2)B₂ is a novel strategy in making UHTCs thermal insulating.     

Gasar—A new Class of Porous Materials

The paper summarizes published data and also deals with technology, structure, applications, and properties of gasars – new porous materials based on original findings obtained by authors. The method consists of melting a material in a gas atmosphere to saturate it with hydrogen and directional solidifying under strictly controlled thermodynamic and kinetic conditions. The materials produced by this method, have a monolithic matrix and pores of proper geometric shapes, providing to gasars higher strength, plasticity, thermal and electrical conductivities as compared with those of other porous materials. Gasar is recommended for prospective application as filters, bearings, metal‐matrix composites.     

Effects of exterior gas pressure on the structure and properties of highly porous SiOC ceramics derived from silicone resin

Silicon oxycarbide porous ceramics were obtained through pyrolysis of a silicone resin filled with SiOC powders via a simple self-blowing process. The effects of exterior gas pressure on the porosity, compressive strength and microstructure of the porous ceramics were investigated. The porosity (total and open) generally decreased with increasing exterior gas pressure. It was possible to control the total and open porosity of porous ceramics within a range of 58.3-69.8% and 43.9-58.4% respectively, by adjusting the exterior gas pressure while keeping the silicone resin content at 70 vol.%. The compressive strength increased with increasing the exterior gas pressure, and the average compressive strength of the porous ceramics was in the range of 3.9-14.9 MPa. Micrographs indicated that with the exterior gas pressure increasing, the final pore structure of porous ceramics became more and more regular and equirotal.