Ceramics-Silikáty 45, (3) 98 - 104 (2001) |
|
EFFECTS OF HOST MICAS, INTERLAYER CATIONS AND THE ADDITION OF PVA ON FORMATION AND POROUS PROPERTIES OF FLUORINE MICA - IRON(III) OXIDE COMPOSITES |
Yamaguchi Tomohiro, Iida Shunsuke, Kitajima Kunio |
Department of Chemistry and Material Engineering,
Faculty of Engineering, Shinshu University,
Wakasato, Nagano 380-8553, Japan
|
Keywords: Pillared mica, Fe₂O₃, Poly(vinyl alcohol), Porous characteristic, Delamination |
Syntheses of Fe₂O₃-pillared fluorine micas have been undertaken using Na-tetrasilicic fluorine mica [NaMg2.5Si₄O₁₀F₂], Nataeniolite
series mica [Na0.5Mg2.5Li0.5Si₄O₁₀F₂] and their Li⁺-exchanged forms as host crystals in the presence or absence of
PVA as a template agent. The properties and structures of the products depend on the species of host crystals and interlayer
cations as well as on the addition of PVA. Fe₂O₃-pillared fluorine micas obtained from the Li-exchanged form of the taeniolite
series mica retained pillared structure up to 600°C and had pores with mean diameter around 3.3 nm. On the other hand, the
products obtained from the Li-exchanged form of Na-tetrasilicic mica with using PVA had the “house-of-cards” structure
consisting of delaminated Fe₂O₃-pillared mica flakes and Fe₂O₃ particles deposited on the external surface of the mica flakes.
They can be called “Fe₂O₃ pillared mica - Fe₂O₃” composites which are featured by mesopore distributions in the range of
3.3 - 6.9 nm, depending on the heating temperature. They gave sintered bodies above 500 °C and exhibited a maximum BET
specific surface area of 110 m²g⁻¹ at 600 °C. |
PDF (0.1 MB) |
|