Abstract
Transparent aqueous solutions of crystalline niobate colloids were obtained by direct reaction of niobium pentaethoxide (NPE) with tetramethylammonium hydroxide (TMAOH). At TMAOH / NPE ≥ 0.7, transparent solutions were available. DLS and XRD measurement showed that the niobate colloids were about 2 nm in size, and had a layered structure.