PRODUCTION METHOD FOR NANOPOROUS ALUMINA SEPARATING FILM HAVING STRAIGHT THROUGH HOLES OF NANO-SIZED DIAMETER OPEN AT BOTH ENDS

摘要

The present invention relates to a production method for a separating film which is at the core of filters and of multifunctional filter devices for the cleansing of substances such as indoor and outdoor air, combustion gases and exhaust gases, trapping devices for global-warming gases or separating devices for various gases and also separating devices for water treatment such as the treatment and purification of drinking water and clean and foul water, river water and waste water and for the purification of meals, drinks, oils, blood, proteins and viruses. A key technical feature of the present invention comprises a production method for a nanoporous alumina separating film having straight through holes of sub-micron and nano-sized diameter opening at both ends, using only a process of anodising an object of any desired form or in the form of a sheet material or hollow cylinder of aluminium (Al) or aluminium alloy of predetermined specification and pattern without any anodisation postprocessing in order to remove an unreacted aluminium layer and remove an oxide barrier layer; and the separating film produced by means of the method includes any separating film used by itself, or used as a composite separating film in which a separating film produced by means of the method is composited with another separating film, or used as a functional composite separating film produced by coating various metal catalyst materials or a functional macromolecular polymer material or a functional ceramic material onto the surface and pores of a separating film produced by means of the method, or used as a multifunctional filter obtained by mixing and laminating a plurality of layers of other functional films on the above two types of film. The use of the above very straightforward production method results in inexpensive unit production costs, and thus the present invention has the advantage of lowering the price of alumina separating films and so expanding the range of use of oxide films, as a consequence of the production of low-cost alumina separating films for various purposes and in various modes.