Surfactant assisted synthesis of precipitated calcium carbonate nanoparticles using dolomite: Effect of pH on morphology and particle size

Synthesis of nanomaterials from readily available minerals for industrial applications is a growing research area. Understanding the causes of their properties becomes handy in utilization. In this study, an effective sucrose solution based method was employed for the extraction of calcium from dolomite to synthesize precipitated calcium carbonate nanostructures with different morphologies and sizes. It was found that 30% (w/v) sucrose solution extracted approximately 91% of calcium from dolomite forming a calcium-sucrate complex. Carbonation was achieved by CO2 bubbling and aqueous sodium carbonate addition. Precipitation was performed under different pH values of 7.5, 10.5 and 12.5 in the absence of an anionic surfactant and in the template of sodium dodecyl sulfate (SDS)/calcium-sucrate at pH 12.5. It was found that CO2 bubbling slightly promotes smaller particles. The anionic surfactant enables particle size and agglomeration reduction while introducing some hydrophobicity. The smallest particles were achieved at a range of 40-55 nm in the presence of SDS/sucrose template and were of spherical morphology. By changing the pH, a tendency to form different polymorphs and shapes of calcium carbonate was observed. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.