PREPARATION OF 1-2-3 YTTRIUM BARIUM COPPER SALT OF CARBOXYLATED CELLULOSE

A procedure is developed for preparing an organometallic precursor, yt trium-barium-copper salt of carboxylated cellulose with an yttrium-bar ium-copper molar ratio of 1:2:3, for the synthesis of a high-temperatu re superconductor. This procedure comprises the preparation of a bariu m salt of carboxylated cellulose with a definite substitution degree, followed by the sorption of yttrium and copper ions by this salt from the combined solution. A convenient formula has been proposed for calc ulation of the composition of the solution, assuring the stoichiometri c sorption of copper and yttrium ions by the barium salt. The formula is based on the fact that the degree of barium substitution depends on ly on ionic strength and is independent of an equivalent fraction of a ny component of the solution. This procedure has been extended to carb oxylated celluloses with various exchange capacities.