TITLE:
The Role of Mg2 and BSA Langmuir Monolayers in Controlling Polymorph and Morphology of CaCO3 Crystal
AUTHORS:
Zhonghui Xue, Ning Xue
KEYWORDS:
Calcium Carbonate, Langmuir Monolayers, Mg2, Bovine Serum Albumin
JOURNAL NAME:
Open Access Library Journal,
Vol.6 No.6,
June
28,
2019
ABSTRACT: Mg2 and bovine serum albumin (BSA) Langmuir monolayers were used as effective crystal nucleation, growth modifiers and template to control the crystallization of CaCO3. Scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used to characterize the polymorph and morphology of crystals obtained at different experimental conditions, respectively. The results indicated that various morphologies such as abacus-bead-like particles, spherical-shaped particles, wood block-like particles, pignut-shell-like particles and the rolling pole shaped particles have been formed at the interface of air-solution. The polymorph of calcium carbonate obtained undergo an evolvement from calcite to vaterite and aragonite with increasing of the molar ratio of Mg2 to Ca2 , which indicated that the ability of Mg2 to induce the formation of aragonite was enhanced as the molar ratio of Mg2 to Ca2 increased. When the molar ratio reached 3, the samples obtained were all aragonite phase of calcium carbonate, which suggests that the presence of Mg2 of subphase solutions was helpful for the formation of aragonite phase in the systems of Mg2 -BSA Langmuir monolayers. The possible formation mechanisms of CaCO3 in different systems were discussed in the paper.