開気孔型Niフォームセル壁への抗菌Agゼオライト粉末の被覆技術の開発

抄録

The purpose of this study is to improve the durability of the downflow hanging sponge reactor—a simple trickling filter system used for purifying water, with an ultimate aim of increasing its water purification capacity. To this end, we have developed a technology to coat the cell wall surface of an open-cell Ni foam with antibacterial Ag zeolite powder, using polyethylene (PE) powder as a binder for the adhesion of the zeolite powder to the cell wall surface. At first, the open-cell type Ni foam was prepared by powder metallurgy using urethane foam as a template, and a mixture of the Ag zeolite and PE powders was prepared using a ball mill. The prepared Ni foam was immersed in an adhesive liquid and then dried completely, following which the mixture of Ag zeolite and PE powders was attached to its cell wall surface by the dipcoating method. Subsequently, heat treatment was used to achieve the adherence of the Ag zeolite powder to the cell wall surface of the Ni foam via PE. Adhesion of the Ag zeolite powder to the cell wall surface of the Ni foam was visually confirmed using a digital camera, a desktop electron microscope viz. “TM-1000” miniscope, and a field emission scanning electron microscope. Therefrom it was observed that when the heat treatment temperatures were 423 K and 433 K, the PE powder retained its spherical shape, and the cubical Ag zeolite was attached to its surface. However, when the heat treatment temperatures were 443 K and 473 K, the spherical PE powder was found to have melted and solidified into a smooth layer, and the Ag zeolite powder was found to be incorporated inside, as well as on the surface, of the PE layer.