Seeded growth of monodisperse gibbsite platelets to adjustable sizes.

Nanosized hexagonal gibbsite seeds are grown from a mixture of dissolved alumina alkoxides at 85 degrees C. Centrifugation reduces the polydispersity by 30%. The seeds can be grown further by adding them to a fresh alkoxide mixture and heating it. This procedure was repeated several times to obtain particles of 570 nm +/- 11% diameter and a thickness of 47 +/- 23%. No indications of a size limit were observed. The thus obtained particles may form easily a columnar phase. Individual gibbsite particles in solution can be seen by confocal microscope.