PMA-b-PAA-controlled synthesis of one-dimensional CaCO₃ superstructures

Crystallization of calcium carbonate (CaCO₃) crystals by a gas-liquid diffusion method has been carried out in aqueous solution using a double-hydrophilic block copolymer (DHBC) poly(maleic anhydride)-b-poly(acrylic acid) (PMA-b-PAA). The as-prepared products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), selected area electron diffraction (SAED), high-resolution transmission electron microscopy (HRTEM) and infrared spectroscopic analysis (FT-IR). Uniform one-dimensional calcite micro/nanostructures with different morphologies are fabricated through an assembled process. The influence of PMA-b-PAA copolymer concentration on the morphology of calcite nano/microwires is investigated, which plays an important role in the morphological control of building blocks composed of one-dimensional calcite crystals. The possible formation mechanism of one-dimensional CaCO₃ crystals was discussed.