Urea and urotropine conversion in the preparation of microspherical metal oxide particles by internal gelation

Formation of uniform and monodisperse zincite crystals in the presence of soluble starch

“…HMT slowly decomposes at 90 uC and forms ammonium hydroxide, which induces precipitation by slowly increasing the pH of the solution, and formaldehyde. 19,20 HMT was used instead of NaOH solutions or aqueous ammonium hydroxide solutions to avoid high local supersaturations when the base was added and to achieve a more homogeneous nucleation process. After 90 minutes at 90 uC, the reaction flask was cooled in an ice bath to terminate the reaction.…”