A combinative flux evaporation slow cooling route to potassium titanate fibres

Two-dimensional potassium tetratitanate (K2Ti4O9) and three-dimensional potassium hexatitanate (K2Ti6O13) fibers have been prepared by slow-cooling calcination, flux melting, flux evaporation and the combinative route of flux evaporation and slow cooling process. In the slow-cooling calcination process, the control of cooling rate was crucial to growth of K2Ti4O9 long fibers. It was also found that the fiber growth reaction is strongly dependent on the mole ratio of flux (F) to raw material (R), which is 7:3 as for the optimum growth conditions in the flux melting process. A columnar shaped potassium titanate fiber has been prepared by the new combinative route of flux evaporation and slow-cooling. Relatively long potassium tetratitanate (K2Ti4O9) fibers (average length is 4 to 5 mm) with prismatic shape could be grown by the combinative growth technique. When this new route is applied for the growth of potassium hexatitanate (K2Ti6O13), monofilament-type fibers (approximate to 1.5 mm) with columnar shape could be obtained. (C) 1998 Elsevier Science B.V.