Biomimetic mineralisation of calcium carbonate using xanthan gum as morphology control agent

Abstract

Biomimetic synthesis of calcium carbonate (CaCO 3) with various sizes and morphologies using organic matrix has become an interesting hotspot. CaCO 3 was synthesised by the reaction of Na 2 CO 3 and CaCl 2 in the presence of xanthan gum (XG). The results showed that the fresh mineralised CaCO 3 /XG were microspheres with large surface area and porosity. The original CaCO 3 /XG microspheres transformed to brick-like CaCO 3 after ageing 7 days at 4°C. During the morphology transformation, CaCO 3 spheres rearranged by attaching to XG molecular, and transformed from a macroscopic view of CaCO 3 microspheres to a hexahedral structure related with the XG uncoiled single chains re-associating into loose several-fold helix. The study demonstrated that environmental effect coupled XG could be one feasible approach to regulate the structure of CaCO 3 .