| 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... |
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