No abstract

A novel process for making nanopowders has been investigated by using the nonhydrolytic solgel synthesis (NHSGS) method, with which around 70% organic solvent can be recycled. Ba 1-x Sr x TiO 3 (BST) nanopowders, for example, were synthesized with the parent precursors Sr(CH 3 COO) 2 , Ba(CH 3 COO) 2 , Ti(n-C 4 H 9 O) 4 , and glacial acetic acid. The properties of BST powders were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), laser scattering, and an Autosorb surface area analyzer. The mean size of primary BST particles is around 30 nm, and the diameters of 50% BST agglomerates are less than 344 nm. With the NHSGS process the period of synthesis was greatly shortened and cost and pollution were largely minimized as well. Furthermore, the NHSGS method can also be applied to the preparation of PbZr 0.95 Ti 0.05 O 3 and PbZr 0.75 Ti 0.25 O 3 nanopowders.

By using a two-step synthetic method, a novel grinding material, SiC and polyimide grinding slice, is prepared. This grinding slice can be used for mechanical planarization of hard and brittle materials, such as silicon, optical glass, advanced ceramics, specials metal, jewelry, disks etc. For observing the physical and chemical properties of the slice, scanning electron microscopy, FTIR spectroscopy, thermal gravimetric analysis, tensile strength, and elongation at break are used. All the experimental data indicate that the SiC/PI slice will be a very useful grinding material for obtaining a precision surface.