TITLE:
Influence of the Precipitating Reagents and Dispersants on the Formation Nano-Aluminum Hydroxide
AUTHORS:
G. Sarsenbay, L. A. Myltykbaeva, R. A. Abdulwalyev, B. M. Sukurov
KEYWORDS:
Nano-Aluminum Hydroxide; Precipitating Reagents; Dispersants; Alkaline Aluminate Solution; Precipitation; Particles; Decomposition; Particle Diameter
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.1 No.5,
November
7,
2013
ABSTRACT: The influence of the
precipitating reagents and dispersants on the formation of nano-aluminum
hydroxide from sodium aluminate solution by chemical precipitation was
investigated. The influence of the dispersed seeds on the decomposi-tion process was
investigated too. The alkaline aluminate solutions were used as original
solutions with a concentration of Al2O3 having 14.78 g/dm3, αk—1.6 and127 g/dm3, αk—1.6.
For the precipitation processes there were used follow-ing precipitating reagents—solutions HCl, NaHCO3 and NH4HCO3 with a concentration of 80 g/dm3, dispersants—PEG 6000,
(NaPO3)6 and Tween 20. For the decomposition process the
dispersed seeds and factories seeds were used. Structural studies of the aluminum hydroxide particles were
carried out by means of the electron-probe microanalysis and scanning electron
microscopy, and phase composition of products was determined by means of X-ray
diffraction analysis.
Ammonium bicarbonate and Tween 20 were determined as the optimal precipitating
reagent and dispersant, correspondingly, resulting in dispersed aluminum hydroxide,
which is used as a seed in the decomposition process. It was established that
this product in form of dispersed seed considerably reduces the duration of the
decomposition process; the maximal decomposition of solution (73.9%) was
observed after injection of dispersеd aluminum hydroxide into solution. The
final aluminum hydroxide having 90% of particles less than 100 nanometers was
obtained within 7 hours of steady decreasing temperature from 70°C to 48°C.