engleski

Effects of urotropin on the formation of beta-FeOOH

beta-FeOOH (akaganeite) in the form of needles, stars, and X- and Y-shaped particles was produced by hydrolysis of 0.1 M FeCl_3 solution at 90 degrees C. After 5 h of hydrolysis a pronounced decrease in particle size and the destruction of beta-FeOOH morphologies, with an increase of urotropin concentration from 0.005 M to 0.25 M, were observed by XRD and TEM. The FT-IR spectra indicated that the bands at 833, 690 and 641 cm(-1), typical of beta-FeOOH, were strongly dependent on the changes in the structure of beta- FeOOH caused by urotropin. After 7 days of hydrolysis, XRD and the FT-IR spectra showed that alpha-Fe_2O_3 was the dominant reaction product for 0.1 M and alpha-FeOOH for 0.25 M urotropin, respectively. The nature of the observed effects is suggested. (C) 1997 Elsevier Science B.V. [References: 4

beta-FeOOH ; urotropin ; hydrolysis ; XRD ; FT-IR

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