【作者】 王永红；

【导师】 刘杏芹； 孟广耀；

【作者基本信息】 中国科学技术大学 ， 材料物理与化学， 2006， 博士

【摘要】 多孔陶瓷膜作为一类新型的分离介质，具有分离效率高、能耗低，寿命长，易清洗、耐腐蚀等一系列独特优点，已经在食品、饮料、化工、冶会、材料、环保等行业获得了广泛的应用。然而，与有机聚合物分离膜相比，无机陶瓷膜的高制备成本和有限的品种规格尚不能满足工业化推广应用，特别是恶劣介质环境和诸如生体、医药等新领域的需求。本论文以发展陶瓷膜改性制备技术，降低其制各成本，改善陶瓷膜的使用性能为目标，研究了氧化锆，氧化铝—氧化钛复合陶瓷分离膜及全氧化钛陶瓷膜的制备，微结构设计和性能优化及其化学稳定性等，并依据本实验室发展的烧结动力学方程，研究了胶态粒子包覆法制备大孔陶瓷支撑体的烧结过程与机理。论文取得了如下创新性结果： 1．从胶体分散稳定理论出发，利用胶态悬浮粒子法进行了氧化锆和氧化钛陶瓷微滤膜制备和表征，研究了分散剂与陶瓷粉体的作用机理。 稳定的陶瓷粉体浆料是成功地制备陶瓷分离膜的工艺核心，我们以立方氧化锆（8YSZ）和氧化钛悬浮浆料为对象，较全面地研究了体系的pH值、温度、固含量、分散剂对浆料分散性与稳定性的影响；详细分析讨论了陶瓷颗粒与有机添加剂的作用机理；以此为工艺基础，采用简单的浸渍—涂覆技术在管状氧化铝支撑体上制得高质量的YSZ和TiO₂微滤（MF）膜，进行了孔径和水通量表征。特别是考察研究了强酸、碱介质中腐蚀后的结构稳定性，表明氧化钛膜比氧化铝支撑体及其膜层具有更好的耐腐蚀性和结构强度，为陶瓷膜在恶劣环境下长期应用提供了优越分离膜材和技术依据。 2．利用溶胶包裹粉体工艺和反应烧结法，以较低的烧结温度制备了大孔氧化铝陶瓷膜支撑体，为陶瓷膜的低成本制备技术开发提供了技术参考，具有显然的材料科学意义和实用价值。 研究发现，在商业钛白粉（主要成分为金红石型氧化钛）的反应助烧作用下，多孔氧化铝陶瓷膜支撑体的烧结温度由通常的超过1600℃降到1300℃。较详细地研究了材料微结构与氧化钛的添加量，有机助剂和烧结温度的关系。结果表明，TiO₂粉体加入量逐步增大到10wt.％时，材料孔隙率逐渐减少，孔（半）径也随之从2.4μm降低至0.8μm；有机添加剂的加入量大于25wt.％会导致混合不均而生坯烧结不充分；1400℃保温2—4小时是比较恰切的烧结条件，超过1600℃烧结容易产生微裂纹，优化条件下制得的多孔支撑体，开孔率可达＞40％，弯折强度为50MPa，而且具有更好的抗碱腐蚀性能。 为了制备大孔氧化铝陶瓷膜支撑体，而又能显著降低烧结温度，提出了一种溶胶包裹的工艺技术；在1350℃—1500℃温度范围内，烧结支撑体的开孔率达到39％，孔径分布为6.63μm—7.71μm，力学强度为＞45MPa；流体渗透性实验结果显示，典型试样的氮气通量为51.3 km³·m^-2·hr^-1·bar^-1，纯水渗透率为98.4m³·m^-2·hr^-1·bar^-1。这些性能参数可通过调节撑体的孔结构、孔径分布、孔隙更多还原

【Abstract】 Inorganic membrane as a new separation media enjoys a large development in such fields as energy storage, environmental protection, metallurgy, food, etc. due to its outstanding performances of higher separation efficiency and lower energy consumption as well as long life, readily rinsing, corrosion resistance. However, comparing to the organic polymer membrane or metal membrane, the shortages of relative high preparation cost and limited types seriously hinders the inorganic membrane development; in particular, the unitary membrane materials properties could not completely satisfy the specific requirements of various new application areas, for example, biotechnology, pharmaceutical and very hash application environments.In order to reduce the fabrication cost and enhance the practical performances, the described works in this dissertation mainly focused on the modified preparation of inorganic membrane. We have successfully prepared such inorganic membranes as zirconia, alumina-titania composite membranes and pure titania ceramic membrane and systematically investigated the relevant membrane properties, microstructure design and their chemical stability. Moreover, the works of sintering mechanism in macroporous ceramic membrane support from sol-coated powder have been done based on a kinetic rate equation developed in our lab. The obviously innovative results can be described in the followings:1.According to the dispersion and stability theory of colloids, we have prepared zirconia and titania ceramic microfiltration (MF) membrane and characterized their membrane structure properties; The interaction mechanisms between ceramic particles and organic additives in suspensions were analyzed and discussed in detail;The suspensions preparation is a key technology for the final high quality membranes formation. The dispersion and stability of suspensions have been systematically investigated as a function of the system factors such as pH value, temperature, solid loadings, etc. As a consequence, the crack free tubular zirconia and titania membranes from the fully dispersed suspensions have been prepared along with the pore size and pure water permeability characterization. In particularly, the corrosion resistance of titania membranes exhibits that the anatase layers are more stable than the alumina supports and its membrane layer in boiling corrosive medium, which provides a wide range of practical application fields in very hash environments with reliable data supports. 2.It is innovatively proposed with a sol-coating ceramic powder routine and reactive sintering for macroporous ceramic membrane preparation at apparently reduced sintering temperature; The obtained results provide the cost effective ceramic membrane exploitation with reliable technical supports and exhibit obviously scientific and practical values;It was found that the sintering temperature of porous alumina ceramic membrane support was reduced from 1600℃ to 1300℃ assisted with commercial titanium white powder (rutile). The correlations of sintered body microstructure with rutile additions, organic pore-forming agents and sintering techniques were investigated in detail. The characterizations show that the porosity decreases with increasing rutile additions in less than 10 wt.% and the pore radius decreases from 2.4 μ m to 0.8 μ m. More than 25wt.% organic additives are not acceptable due to the non-uniform mixing and thus poor sintering of powder compacts. And the microcracks occurred once sintering temperature surpassed 1600℃ and the 1400℃/2-4 hrs sintering conditions were adequate to prepare porous alumina support with >40% open porosity and 50MPa mechanical strength along更多还原