PREPARATION OF CAF2 FIBERS

Solid and/or hollow CaF2 fibers were prepared from aragonite whiskers, Aragonite (CaCO3) whiskers with diameters of similar to 2 mu m were c onverted into CaF2 fibers without deformation by treatment with HF aqu eous solution, The resultant CaF2 fibers were polycrystalline with lar ge specific surface areas of similar to 60 m(2) . g(-1), and they dens ified when heated at 800 degrees C, The thickness of the CaF2 reaction layer can be controlled by the concentration of the HF aqueous soluti on used, Hollow CaF2 fibers were successfully prepared when CaCO3 whis kers covered with CaF2 were leached with HCl.