Mechanism of Crystal Growth Habit Modifiers on the Morphology of α-CaSO_4·0.5H_2O Crystal

Crystal growth habit modifiers were used to control the morphology ofα-CaSO4·0.5H2O crystal prepared by hydrothermal method.The mechanism of habit modifiers controlling the crystal shape ofα-CaSO4·0.5H2O of habit modifiers was discussed on the basis of influences of habit modifiers on the shape of crystal terminal ends and the structures of crystal faces.The results show that Al 3+and organic acids all can change the morphology ofα-CaSO4·0.5H2O crystal and the crystal faces they affected are different. Al 3+mainly act on the{001}faces.When organic acids exist alone,they would adsorb on the pyramidal faces ofα-CaSO4·0.5H2O crystal terminal ends.When Al 3+coexist with organic ions,they would form complex ions and adsorb on the{001}faces ofα-CaSO4·0.5H2O crystal.