GeO2 particles with a narrow size distribution were synthesized using hydro
lyzing germanium tetraethoxide (GTE) in a 2,2,4-trimethylpentane solution o
f sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as a function of water cont
ent (R-w=[H2O]/[AOT]). Their shape was observed to be polyhedral in the abs
ence of excess water, whereas it was cubic in the presence of bulk-like wat
er. The size and shape varied with R-w such that the solubilized state of w
ater in effect determined the growth process. In addition, by examining the
time-dependent growth of GeO2, particles in a W/O microemulsion (R-w=20),
we clarified that water condensation of hydrolyzed GTE is the rate-limiting
step in particle growth. (C) 1999 Elsevier Science B.V. All rights reserve
d.