On the Mechanism of Dissolution of Boehmite Nanocrystallites in the Acidic Medium

The process of dissolution of boehmite nanocrystallites in acidic hydrosols is investigated at a temperature of 90°C. The average size of crystallites is determined from the width of peaks on X-ray diffraction patterns. It was established that, during the dissolution of more than 50% of the dispersed phase of sols, the average size of crystallites decreases slightly. This means that a part of the crystallites is dissolved completely, whereas the size of crystallites of the other part virtually does not decrease. The mechanism of such an unusual behavior of sols is discussed. Reversibility of the compression of AlOOH bilayers in boehmite crystallites in the presence of electrolytes was established.