Continuous synthesis of spherical beads of tungsten(VI)-containing materials

Monodispersed beads of tungstic acid (5% dispersivities), which are support ed in a hydrophilic poly(acrylamide) matrix, have been prepared, The diamet ers of the beads may be modified within the range 0.5-2 mm by changing the experimental conditions. The specific surface areas of the materials are ab ove 100 m(2) g(-1), with extensive mesoporous regions. On calcination, diff erent successive crystalline phases have been identified. Calcination at hi gh temperature in air yields rather brittle beads of tungsten(VI) oxide. Th e synthesized materials are suitable for catalyzed oxidation reactions of a lkenes.