Gas transport properties of CoAlPO4-5/PC membranes

✍ Scribed by Shih-Hsiung Chen; Shiow-Shyung Lin; Dong-Jang Chang; Jing-Song Chang

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 147 KB
• Volume: 77
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000705)77:1<89::aid-app12>3.0.co;2-5

✦ Synopsis

The transport phenomena of oxygen and nitrogen across a pure polycarbonate (PC) and CoAlPO 4 -5/PC membranes were studied. Various CoAlPO 4 -5 membranes with different cobalt content were added to polycarbonate membranes to improve the gas transport performance. Oxygen and nitrogen isotherms were studied. Solubility of oxygen and nitrogen was greatly increased by adding CoAlPO 4 -5 to the membranes, which also resulted in a higher solubility ratio of oxygen to nitrogen. It might be that a pinhole of the membrane caused the increase in diffusivity and a decrease in selectivity when excess CoAlPO 4 -5 was added. The results also showed that CoAlPO 4 -5 with a higher cobalt content would more effectively increase the gas solubility, but make only a minor change in the solubility ratio of oxygen to nitrogen. It was found that the increase in oxygen to nitrogen selectivity was mainly due to an increased diffusivity ratio of oxygen to nitrogen when CoAlPO 4 -5 was added into the membranes.