J.F. Hochepied and A.P.A. Oliveira, , École des Mines de Paris, CENERG/SCPI,
60 Bvd Saint Michel, F-75272 Paris Cedex 06, France.
The synthesis of particles with controlled morphology, size and
crystalline structure for specific applications has led to the
development of many processes in the last decades. Controlled
precipitation is the most employed method at industrial level. Among
ceramic materials, zinc oxide has diversified applications (catalysis,
electronic devices, pigments).
The scope of this work was to investigate the influence of
precipitation parameters, such as zinc salt nature and additives on
particle characteristics. All experiments were performed with soda at
pH=10.5 and 25C.
With zinc nitrate, 1ľm sized zinc oxide particles (composed by
assembled 30nm crystallites) were obtained with star-type morphology.
Zinc sulphate led to zinc oxide and hydrated zinc sulphate-hydroxide
with a mixture of morphologies and sizes. We compared the
precipitation of zinc nitrate in sodium sulphate solution and sodium
dodecylsulphate solution (direct micelles). With sodium sulphate,
precipitation led to 100nm to 300nm half-ellipsoids, exhibiting
evolution from distilled water results and zinc sulphate salts
results. With sodium dodecylsulphate, particle size is sensitively
reduced under 200nm. This study evidences the effect of additives for
morphology and size control of submicron particles constituted by