Synthesis and characterization of new CaCO3/poly(2-acrylamido-2-methylpropanesulfonic acid–co-acrylic acid) polymorphs, as templates for core/shell particles

The crystallization of CaCO3 particles from aqueous solutions in the absence and presence of a strong/weak anionic copolymer, poly(2-acrylamido-2-methylpropanesulfonic acid–co-acrylic acid) (PAMPSAA) is discussed in this paper. Vaterite/calcite polymorphs with different sizes and spherical shapes were obtained. The products were characterized by infrared spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, flow particle image analysis, laser diffraction technology, and SEM and optical microscopy. Oppositely charged chitosan and PAMPSAA were assembled onto carbonate colloidal particles in a layer-by-layer manner to yield core–shell structures.

► Crystallization of CaCO3 with or without a strong/weak anionic copolymer, PAMPSAA.
► Particles were characterized by FTIR, XRD, XPS, FPIA, SEM, and optical microscopy.
► Vaterite is the main polymorph in CaCO3 particles, PAMPSAA favor calcite formation.
► Larger, smoother, and more circular particles were obtained for CaCO3/PAMPSAA.
► Chitosan and PAMPSAA assembling onto carbonate particles yield core–shell structures.