硅藻土基多孔陶瓷的制备及性能研究

本实验以硅藻土为主要原料，天然有机细粉为造孔剂，水玻璃为高温粘合剂，经半干压成型，常规烧成，制出了性能优良的硅藻土多孔陶瓷，随着造孔剂的加入量、烧成制度的改变，气孔率从47％增加至71％，最大孔径也随之从1－10μm变化，密度从1．3g/cm^3到0．7g/cm^3改变，抗压强度则从11．05MPa降至4．38MPa。不同孔径及显气孔率的材料，在饮料、水的净化及催化剂载体等方面的应用有很好的前景。     

高孔隙率多孔陶瓷滤料的制备

以漂珠为骨料，以小米或聚苯乙烯颗粒、碳粉等为造孔剂，制得显气孔率为66．43％的高孔隙率多孔陶瓷滤料。通过SEM及性能测试手段，对多孔陶瓷滤料样品性能及其影响因素、微观结构和活化机理作了详细分析与探讨。关键词：高孔隙率，多孔陶瓷滤料，微观结构，活化。     

多孔陶瓷的制备及应用

根据成孔原理，多孔陶瓷成型工艺可分为七大类，对各种工艺进行了简要论述结合作者的工作对有机泡沫体浸渍工艺中的关键技术进行了较详细的探讨，并简要描述了两次离心挂浆工艺的过程及实验结果。最后，展望了多孔陶瓷的应用前景及尚待解决的问题。     

多孔吸音陶瓷的制备

以20wt%塑性粘土,10wt%球土和70wt%低温砂为陶瓷基料,木炭屑和锯末为造孔剂,制备了多孔吸音陶瓷.主要探讨了造孔剂用量及配比对样品显气孔率和吸音性能的影响,并采用SEM对其显微结构进行了表征.结果表明:当以基料76%,木炭屑20%,锯末4%时,多孔层吸音性能和吸音效果最佳.     

堇青石质多孔陶瓷的制备及性能研究

采用氧化铝、烧高岭、烧滑石为原料,可溶于水的有机物质尿素作为造孔剂,TiO2为添加剂,于6MPa压力下干压成形,1350℃下保温60min进行烧成,制备出以堇青石为主晶相的多孔陶瓷体。通过XRD分析手段对不同温度合成堇青石主晶相进行了分析,并用SEM观察了烧结后多孔陶瓷的微观结构。探讨了可溶性造孔剂用量、TiO2添加量、烧成制度等因素对堇青石质多孔陶瓷性能的影响。制备的多孔陶瓷体气孔率接近于70%,抗压强度达到3.310MPa。     

铝土矿尾矿多孔陶瓷的制备研究

以铝土矿尾矿为主要原料,分别选用碳粉、石墨粉、碳酸氢钠和淀粉作为造孔剂制备出铝土矿尾矿多孔陶瓷试样,采用抗弯测试、XED、SEM等对其主要力学性能和热物理性能进行测试与表征,结果表明:不同的造孔剂制备的铝土矿尾矿多孔陶瓷试样的抗弯强度、显气孔率、晶相组成和显微组织不同;以碳粉作为造孔剂制备的铝土矿尾矿多孔陶瓷试样的综合性能较好,因此最终选用碳粉作为制备铝土矿尾矿多孔陶瓷试样的造孔剂。     

造孔剂种类对粉煤灰多孔陶瓷性能的影响研究

以工业废弃物粉煤灰为主要原料,采用添加造孔剂法,分别以淀粉和煤粉为造孔剂,模压成型,在1000℃固相烧结制备粉煤灰多孔陶瓷,用SEM测试分析手段表征不同条件下粉煤灰多孔陶瓷的微观结构变化,研究了造孔剂种类及用量对显气孔率、抗弯强度、吸水率、体积密度、耐酸碱性能的影响.     

多孔陶瓷的制备、性能及应用：（I）多孔陶瓷的制造工艺

多孔陶瓷的制备方法很多，其成孔机理主要有机械挤出、颗粒堆积、成孔剂、发泡、多孔模板、凝结结构成孔。本文根据成孔机理的不同综述了多孔陶瓷的制备工艺最新研究进展。     

多孔陶瓷的制备,性能及应用

多孔陶瓷性能特点,应用广泛,并为节能等相关行业带来进步。本文对多孔陶瓷的种类,制备,结构与性能表征,应用,国同发展等作了一个概述。     

多孔莫来石陶瓷的近净尺寸制备及性能

以蓝晶石和Al₂O₃粉体为原料、PMMA微球为造孔剂、Isobam104为分散胶凝剂,结合凝胶注模工艺与造孔剂法,实现了收缩率可控的多孔莫来石陶瓷的近净尺寸制备。研究了烧结温度对相组成的影响以及固相含量对样品微观结构、相组成、收缩率、气孔率及抗压强度的影响。结果表明：随着固相含量的增加,样品在1 500℃烧结后收缩率先减小后增大,在固相含量为30%（体积分数）、造孔剂含量为30%（质量分数）时,样品的总收缩率接近于0,实现了多孔莫来石陶瓷的近净尺寸制备。多孔莫来石陶瓷呈现出较高的气孔率（60.4%）、较小的平均气孔尺寸（3.75μm）和较高的抗压强度（8.3 MPa）。利用制备过程中的体积膨胀效应,可以有效地控制多孔陶瓷制备过程中的收缩率,实现了多孔莫来石陶瓷的近净尺寸制备,对制备大尺寸复杂形状多孔陶瓷部件、降低加工成本具有重要参考价值。     

壳聚糖-胶原多孔支架的制备研究

本研究的目的就是利用细胞亲和力较好的胶原与壳聚糖复合,制备具有较好细胞亲和力的组织工程复合支架。在研究中采用冷冻诱导相分离的方法制备了壳聚糖(Cs)和胶原溶胀液(Co)质量比为1：2、1：3、1：4、1：5的4种成分的复合多孔支架,并对支架的孔结构、吸水性、孔隙率和溶胀性等特性进行了评价。结果显示,制备的复合多孔支架孔隙率均在90％以上;不同成分的支架孔径大小不同,胶原含量越高,孔径越大;支架内部孔隙连通：残留的醋酸在超声波作用下用碱液中和并干燥后,支架浸入水中基本无溶胀,保持了原有的形貌。     

多孔氧化铝支撑体制备工艺的研究

本文研究了多孔氧化铝支撑体的制备工艺对其性能的影响,发现原料粉体的粒度、物料的成型方法、坯体的干燥环境及坯体的焙烧制度对支撑体的性能有重要影响。在研究的基础上制定了本实验所采用的各种工艺条件,并由此制备出了性能优越的多孔氧化铝支撑体。     

A novel approach for the fabrication of carbon nanofibre/ceramic porous structures

This paper describes the fabrication of hybrid ceramic/carbon scaffolds in which carbon nanofibres and multi-walled carbon nanotubes fully cover the internal walls of a microporous ceramic structure that provides mechanical stability. Freeze casting is used to fabricate a porous, lamellar ceramic (Al₂O₃) structure with aligned pores whose width can be controlled between 10 and 90 μm. Subsequently, a two step chemical vapour deposition process that uses iron as a catalyst is used to grow the carbon nanostructures inside the scaffold. This catalyst remains in the scaffold after the growth process. The formation of the alumina scaffold and the influence of its structure on the growth of nanofibres and tubes are investigated. A set of growth conditions is determined to produce a dense covering of the internal walls of the porous ceramic with the carbon nanostructures. The limiting pore size for this process is located around 25 μm.     

多孔陶瓷载体氧化铝涂层的研究

分别用纳米γ-Al₂O₃和SB粉制备了多孔陶瓷载体的Al₂O₃涂层。BET法测定了多孔陶瓷载体Al₂O₃涂层改性前后比表面积的变化。由SEM照片观察多孔陶瓷载体涂层改性前后表面和断面的形貌。结果表明，这两种方法对多孔陶瓷载体涂层改性均有效可行。     

Study on mechanical properties and fire resistance of porous ceramic silicone rubber

Porous ceramic silicone rubber (PCSR) has an excellent ablative resistance because of its strong carbon layer structure after burning. However, as a marine sealant material, it also needs to have better mechanical properties for better application. In this study, PCSR composites were prepared by compounding with different additives and different viscosity base adhesives, and their fire resistance, tensile properties, and bond strength of multiple substrates at different temperatures were investigated and compared. When the ratio of 20,000 to 80,000 viscosity matrix adhesive is 3:7, the material prepared by adding deketoxime crosslinker and silane coupling agent containing amino and epoxy groups together can reach more than 1.4 MPa tensile shear strength at 150°C. Sintering experiments have shown that PCSR composites can still maintain the strength and integrity of the carbon layer structure, and the results of the A-60 standard fire resistance test for cable and pipe penetration devices have shown that marine PCSR sealants can effectively prevent flame propagation.     

Electroconductive coatings on porous ceramic supports

The preparation of porous conductive coatings on porous ceramic supports for potential use in electrosynthesis, anodic decomposition of organic compounds and electrosorption units is described. The prepared conductive coatings on porous ceramic supports consisted either of carbon, gold or nickel, or a combination of carbon and gold. Carbon coatings were obtained by pyrolytic decomposition of liquid petroleum gas (LPG), gold was sputter coated and nickel coatings were formed by electroless plating. The permeability for water and electrical resistance of each coated support were measured and compared. Pyrolytic carbon was deposited throughout the support whereas the nickel and gold coatings were formed on the outer surface of the support. The resistance of a carbon coating could be regulated between 0.5 and 2 cm^–1 of support while the permeability of the carbonized support was as high as 75% of the permeability of the unmodified support. The nickel and gold coatings had no significant effect on the permeability and could be prepared with a resistance of 0.25 and 1 cm^–1 of support, respectively.     

Fabrication of ceramic membranes on porous ceramic supports by electrophoretic deposition

Abstract

Nanoporous alumina membrane and continuous zeolite L membrane were fabricated on the inner surface of microporous alumina tubes. In the former case, an electrophoretic deposition (EPD) technique was used for the deposition of bimodal alumina particles for the subsequent low temperature sintering. In the latter case, the EPD was used for the seeding process of zeolite L particles for the subsequent hydrothermal synthesis. A thin layer of polypyrrole was synthesised on the inside wall of the porous tubes by the chemical polymerisation of pyrrole to give the wall electric conduction for the EPD electrode. The thickness of the coating layers was controlled by altering the applied voltage and deposition time. The interfacial connection of the alumina or zeolite coated layer and the substrate was evaluated by SEM observations before and after the thermal treatment. The nanoporous structure of the alumina membrane was also characterised by a pore size analyser.     

Multilayer porous aluminosilicate ceramic

Multilayer aluminosilicate materials used for treating drinking water were investigated. The basic results of the experimental studies obtained in developing the process conditions for fabrication of aluminosilicate filter elements are reported.