title: Important property of polymer spheres for the preparation of three-dimensionally ordered macroporous (3DOM) metal oxides by the ethylene glycol method: the glass-transition temperature.
abstract: We demonstrate that the glass-transition temperature (T(g)) of a polymer sphere template is a crucial factor in the production of three-dimensionally ordered macroporous (3DOM) materials. Metal nitrate dissolved in ethylene glycol-methanol was infiltrated into the void of a face-centered, close-packed colloidal crystal of poly(methyl methacrylate) (PMMA)-based spheres. The metal nitrate reacts with EG to form a metal oxalate (or metal glycoxylate) solid (nitrate oxidation) in the void of the template when the metal nitrate-EG-PMMA composite is heated. Further heating converts metal oxalate to metal oxide and removes PMMA to form 3DOM materials. We investigated the effect of T(g) of PMMA templates and obtained clear evidence that the solidification temperature of the metal precursor solution (i.e., nitration oxidation temperature) should be lower than the T(g) of the polymer spheres to obtain a well-ordered 3DOM structure.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima 739-8527, Japan. sadakane09@hiroshima-u.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sadakane
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sasaki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Wataru
authors.initials: W
authors.lastname: Ninomiya
authors.forename: Wataru
authors.initials: W
authors.lastname: Ueda