Chemical stability, ceramic membranes

Chemical stability - Ceramic membranes are not degraded by organic solvents and can withstand exposure to chlorine. Many crystalline oxides are relatively insoluble in acidic and alkaline media hence cercunic membranes coitposed of such oxides should be relatively inert under extreme pH conditions. 

The ceramic membrane has a great potential and market. It represents a distinct class of inorganic membrane. In particular, metallic coated membranes have many industrial applications. The potential of ceramic membranes in separation, filtration and catalytic reactions has favoured research on synthesis, characterisation and property improvement of inorganic membranes because of their unique features compared with other types of membrane. Much attention has focused on inorganic membranes, which are superior to organic ones in thermal, chemical and mechanical stability and resistance to microbial degradation. 

J.M. Hofman-Ziiter, Chemical and Thermal Stability of (Modified) Mesoporous Ceramic Membranes , PhD Thesis, University of Twente, 1995. 

One way to improve chemical stability of a ceramic membrane is to introduce another oxide to the system as mentioned previously. On the other hand, even a small quantity of an ingredient present in the membrane composition may appreciably change the resulting chemical resistance in an undesirable direction. An example is cakia-stabilized zirconia which is likely to offer less resistance to acids than pure zirconia. 

Due to their chemical stability and strucUiral rigidity, ceramic membranes have been tested, and in some cases, used for the pretreatment of industrial waste waters. 

Due to their greater chemical and thermal stabilities and narrower pore size distributions compared to polymer membranes, ceramic membranes are attractive in a number of filtration applications related to the fermentation broths. They can be used for either upstream or downsueam processing. 

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