Controlled synthesis of hollow calcite microspheres modulated by polyacrylic acid and sodium dodecyl sulfonate

Hollow CaCO₃ microspheres were successfully synthesized through the precipitation reaction of Na₂CO₃ with CaCl₂ in the presence of polyacrylic acid (PAA) and sodium dodecyl sulfonate (SDS) at 80 °C. The concentration of SDS is an important factor to control the synthesis of hollow CaCO₃ microspheres. X-ray diffraction confirmed that the hollow CaCO₃ microsphere consists of calcite crystals. The “pearl-necklace model” of PAA/SDS micellar aggregates serves as the spherical templates to generate hollow microspheres of CaCO₃ crystals in the precipitation system.