Effect of PCL-b-PAA Micelle on Crystallization of CaCO3
Li Cuizhen1,2 Zhang Yan1Hu Xiaoyi1 Lang Meidong*,1
(1 Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237)
(2 Key Laboratory of Radioactive Geology and Exploration Technology Fundamental Science for National Defense, East China Institute of Technology, Fuzhou 344000)
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.