Morphology of nordstrandite [Electron microscopy, montmorillonite]

Nordstrandite was obtained synthetically by precipitation of Al(OH) 3 at pH 9.0 to 11.0 in citrate or malate systems with Al: carboxylic acid molar ratios of 10–100 in the absence and in the presence of montmorillonite. Examination by transmission and scanning electron microscopy showed that the nordstrandite had a tabular morphology in the clay-free systems with Al: carboxylic acid ratio >50. Because the inhibiting effect on crystallization of the citrate or malat e anion decreases with increase in pH, the crystal size varied from 50. Тормозящій эффект на кристаллизацию цитратных и малатных анионов уменьшается с ростом величины pH и поэтому размеры кристаллов изменялись от