Synthesis of aqueous nanodispersed nanocrysralline ceria suspensions by a novel organic/inorganic precipitation method

A low cost and environmentally friendly methodology was developed to produce highly stable, nanodispersed, aqueous suspensions of uniform CeO2 nanocrystals with a mean size at around 5 nm. The synthesis is a hybrid precipitation route that takes place at room temperature from a cerium nitrate solution in the presence of a functional polymer that can act both as complexing and dispersing agent. A hyperbranched poly(ethylene)imine (PEI) or the sodium salt of carboxy-methylated poly(ethylene)imine (Trilon P) were investigated for this purpose with very positive results concerning the stability and the dispersion degree of ceria. Between them, the nanoceria suspensions containing the Trilon P are extremely stable and almost monodispersed, whereas PEI based suspensions show loose nanosized agglomerates according to TEM and even DLS measurements.