Morphosynthesis of CaCO3 at different reaction temperatures and the effects of PDDA, CTAB, and EDTA on the particle morphology and polymorph stability

Facile precipitation of CaCO3 was performed using aqueous solutions of CaCl2 with Na2CO3 over a wide range of mixing and aging temperatures. The precipitation process was then repeated in the presence of PDDA, CTAB, and EDTA at the mixing temperatures of 30 °C, 50 °C, 70 °C, and 90 °C. The presence of these additives was seen to greatly suppress the formation of aragonite. Among these additives, EDTA was the one that showed the most prominent effects on particle morphology of CaCO3. The sequence of pH adjustment appeared to be a critical factor for the additive functionality.

Facile precipitation of CaCO3 was performed using aqueous solutions of CaCl2 with Na2CO3 over a wide range of mixing and aging temperatures. The precipitation process was then repeated in the presence of PDDA, CTAB, and EDTA. Among these additives, EDTA was the one that showed the most prominent effects of particle morphology of CaCO3. The functionality of the additives was seriously affected by temperature. At 30 °C, the additives showed limited effects on the morphogenesis of CaCO3. At 90 °C, however, these additives were observed to affect the particle morphology, aspect ratio of CaCO3 crystals, and to greatly suppress the formation of aragonite. The sequence of pH adjustment appeared to be a critical factor for the additive functionality.Figure optionsDownload as PowerPoint slide