Hydrolysis-condensation process of .beta.-diketonates-modified cerium(IV) isopropoxide

Fabrication of high-surface-area γ-alumina by thermal decomposition of AACH precursor using low-temperature solid-state reaction

“…Possible mechanism for high surface area g-Al 2 O 3 The gains in high surface area and pore volume upon thermal treatment are possibly partly due to the development of intrapatricle porosity [16,35,36]. The formation of g-Al 2 O 3 phase can be described by the following reaction:…”

Synthesis of experimental models for molecular inorganic geochemistry—A review with examples

“…Of special significance are the variety of ''TiOx'' clusters which are stabilized by carboxylate bridges (see below) and a detailed study on controlled Ce(IV)-alkoxide hydrolysis in the presence of acetylacetone which isolated some discrete molecular clusters and moreover established their effect on sol and gel properties. In the latter, an extensive study of the hydrolysis of the alkoxide in the presence of acetylacetone showed that increasing the ratio q = [acac]/[Ce] determines whether the hydrolysate appears as particles, a sol, a turbid gel, a clear gel or as the soluble molecular cluster having the stoichiometry: Ce 6 (l-O) 4 (l-OH) 4 (acac) 12 (Ribot et al, 1991). In and Sanchez (2005) highlight the value in carrying out detailed kinetic studies on polymerizing metal-alkoxide solutions.…”

Production and shaping of high performance phosphors by using the sol–gel process: Yttrium aluminum garnet (Y3Al5O12)

“…After 2 h reflux at 85°C of the last solution [17,18], acac was added so that complexation ratio R C ¼ ½AlðOPr i Þ 3 ½acac ¼ 1. It prevents the sol from the hydrolysis-condensation phenomenon acting as a protecting belt, which entails such a steric hindrance that the polymerization process does not occur [16].…”

“…acetic and malic acids, and b-diketones or allied derivatives [13,14]. Among these modifiers, acetylacetonate (acac) has proved to be very efficient for stabilizing several isopropoxides, close to those used for YAG synthesis [15,16]. This is the reason why acac has been used in this study.…”