PROCESS FOR PREPARING DISPERSIBLE SULFATE, PREFERABLY BARIUM SULFATE NANOPARTICLES

摘要

The invention is directed to a process for the manufacture of optionally doped nanoparticulate metal sulfate wherein the metal is selected from polyvalent metals or monovalent transition metals, said process comprising the step of heating a reaction mixture comprising a) a polar organic solvent comprising at least two hydroxy groups or a polar organic solvent comprising at least one sulfoxide group, b) a source of a polyvalent metal or monovalent transition metal, a sulfate source, and optionally a dopant metal source, and c) a base selected from i) bases having an aromatic N-containing heterocycle with the exception of imidazole, ii) bases having an aliphatic N-containing heterocycle, iii) aliphatic hydroxy-substituted amines, iv) aliphatic polyamines, v) aromatic amines, vi) ammonia and ammonia-releasing compounds, and vii) metal hydroxides. The invention is also directed to the resulting metal sulfate nanoparticles.