HYDROLYTIC FORMATION OF SUBMICRON IRON(III) OXIDES FROM DILUTE FERRIC NITRATE SOLUTIONS

Two series of 0. 001 M Fe(NO//3)//3 solutions, having NaOH/Fe molar ratios ranging from 0 to 3. 1, were prepared by diluting a 0. 5 M Fe(NO//3)//3 stock solution with water followed by hydrolysis at 70 degree C. The preparations differed only in the initial temperature of the water for dilution, but the final products were very different in particle size, morphology, and crystallinity. The results suggest that the temperature of water for solution preparation plays a key role in the size and nature of the initial hydrolytic product that, in turn, played a key role in the rate of redissolution and recrystallization.