Chemical modification of carbon-coated anodic alumina films and their application to membrane filter

An anodic aluminum oxide film that has uniform and straight nanochannels wa s exposed to propylene at 800 degreesC, resulting in uniform carbon deposit ion on the inner-surface of the channels as well as the external surface of the film. The carbon-coated aluminum oxide film was then chemically modifi ed by either fluorination or HNO3 treatment. The change in channel structur e due to the carbon deposition and the subsequent chemical modification was analyzed. Gas permeation behavior through these films was examined by usin g He and N-2. Furthermore, the films were applied to pervaporation separati on of water/ethanol mixture and it was found that water preferentially perm eated the fluorinated film. The present study demonstrated that even a memb rane whose pore size is as large as 24 nm exhibits selectivity in pervapora tion. (C) 2002 Elsevier Science B.V. All rights reserved.