engleski

Forced hydrolysis of FeCl3 solutions in the presence of sodium dextran sulphate

The effect of sodium dextran sulphate (Mw= 500, 000) on the forced hydrolysis of FeCl3solutions was investigated using amicrowave-assisted method. Reference samples obtained upon 10 to 120 min of forced hydrolysis of the FeCl3solution showedthe presence of an α- Fe2O3phase alone. After 10 min of the forced hydrolysis of FeCl3in the solution containing sodium dextransulphate, α- Fe2O3and additionally β-FeOOH precipitated. The Mössbauer spectra of α-Fe2O3precipitated in the presence ofsodium dextran sulphate showed a significant broadening of spectral lines accompanied by decreased values of the hyperfinemagnetic field. This was explained by lower α-Fe2O3crystallinity. The FESEM of reference α-Fe2O3samples showed cube- likeparticles of good uniformity in the submicrometer range. In the presence of dextran sulphate polymer, the α-Fe2O3particles ofvarying sizes and close to egg-like shape were obtained as a result of the specific adsorption of sulphates on the oxide surface andsteric conditions created by dextran branches.

Forced hydrolysis ; Fe3+ions ; α-Fe2O3 ; β-FeOOH ; Sodium dextran sulphate

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