2009 年 34 巻 4 号 p. 719-722
A cellulose/copper blend was prepared by a mechano-chemical treatment using a high-speed ball mill called a planetary mill. Cellulose and copper in the blend were mixed in the submicron scale, as observed by scanning probe microscopy using the surface potential microscopic mode. The treatment made the cellulose crystal almost amorphous while the molecular weight of the cellulose retained 70% of its original value. X-ray diffraction patterns of the copper remained unchanged. Removal of cellulose from the blend by firing or enzymatic decomposition yielded porous copper, the surface area of which was 18 m2/g. The copper fragments appeared not to be isolated but rather were connected to each other at junction points. Such a porous structure must prevent cohesion of each metal fragment to retain its effective surface area. Many nano-metals have a problem, in that the cohesion of the particles decreases their apparent surface area resulting in a decrease in the efficiency for their practical use. Therefore, if porous metals prepared by this method are applied as catalysts or electrodes, a high efficiency can be expected.
