Process for the production of porous ceramics with the composition Pb (Zr¶x¶Ti¶1¶-¶x¶) 0¶3¶

摘要

Production of a porous ceramic composition. :Pb(ZrxTi1-x)-O3 (where x = 0 -0.9) comprises : (a) forming a 0.5 molecule solution containing polar solvents with complexing chelating properties, Pb(II) or Pb(IV) carboxylates derived from (un)substituted (un)saturated cyclic or aromatic 1-18C (hydroxy) carboxylic acids, and Ti-or Zr-compound(s) derived from compounds of formula : M(or)4 (where M = Ti or Zr; and R = 1-10C linear, branched or cyclic alk(en)yl); (b) hydrolytically condensing the resulting solution with at least 2.5 equivalents water optionally in presence of a dissolving intermediary and/or a catalyst; (c) ageing the resulting gel; (d) replacing the polar solvent into the pores of the gel by a non-chelated overcritically dry solvent of low polarity; (e) drying the gel formed; and (f) tempering the resulting aerogel until complete crystallisation of the required phase.