The crystallization of calcium carbonate (CaCO₃) in poly(ε-caprolactone)-block-poly(acrylic acid) (PCL-b-PAA) copolymer micelle solution was studied using Na₂CO₃ and CaCl₂ as reactive reagent. The composition and morphology of CaCO₃ were investigated in different micelle concentrations. Hydrogen nuclear magnetic resonance (¹H NMR), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and conductivity meter were employed to analyze the structure of block copolymer, the morphology of the micelles, the polymorphs and morphologies of CaCO₃. The results showed that the crystallization of CaCO₃ was strongly influenced by the PCL-b-PAA micelle. Metastable vaterite, which cannot be formed in pure water, was readily obtained in the presence of PCL-b-PAA micelle. As the micelle concentration increased, the content of vaterite increased and then decreased, in the meanwhile, the morphologies of CaCO₃ transformed from irregular to sphere.

Key words: amphiphilic block copolymer, micelle, calcium carbonate crystallization, vaterite