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Packaging of Sol–Gel‐Made Porous Nanostructured Titania Particles by Spray Drying
Author(s) -
Kim Jinsoo,
Wilhelm Oliver,
Pratsinis Sotiris E.
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb01097.x
Subject(s) - peptization , chemical engineering , materials science , anatase , rutile , crystallite , porosity , spray drying , slurry , nanoparticle , sol gel , metallurgy , composite material , nanotechnology , chemistry , organic chemistry , photocatalysis , engineering , catalysis
Porous titania granules (1–20 μm) were made by spray drying titania solutions with and without peptization. An unpeptized titania slurry was prepared by hydrolyzing titanium tetraisopropoxide, while a peptized sol was prepared by adding nitric acid to the slurry. The characteristics of the granules depended on the feed solution properties. In particular, granules from the unpeptized slurry showed a bimodal pore size distribution (PSD), with a rough surface attributed to hard aggregates; granules from the peptized sol showed a monomodal PSD, with a smooth surface of well‐packed nanoparticles. The effect of dopants (alumina and zirconia) also was investigated. Doping slowed the crystallite growth of the titania granules, as well as the anatase‐to‐rutile phase transformation. All of the peptized granules exhibited a monomodal PSD of intraparticle pores, from 2 to 15 nm. However, the PSD of the pure titania granules collapsed at 600°C, mainly by phase transformation.