Abstract:

Spherical calcium carbonate has broad application prospects in coatings，papermaking，adhesives，plastics，inks，cosmetics，drug loading and sustained release due to its high specific surface area，low density，excellent mesoporous properties，excellent dispersibility and smoothness.In this paper，polymorphous calcium carbonate（CaCO₃） was prepared by simple double decomposition method with calcium hydroxide and sodium carbonate as raw materials，sodium dodecyl sulfate（SDS），glutamic acid，proline and arginine as crystal control agents，and the products were characterized by scanning electron microscope and X-ray diffractometer.The results showed that the morphology of CaCO₃ was mainly elliptic under SDS control.Under the control of amino acids，the morphology of CaCO₃ was mainly irregular and massive.Under the condition of SDS and amino acid double template，the morphology of CaCO₃ was gradually shortened from irregular rod shape to ellipse as amino acids changed from alkaline to neutral and then to acidic，and finally formed a regular spherical structure.The effects of reaction temperature，inducer dosage，reaction time and pH value on the crystal form and morphology of calcium carbonate particles were investigated，and the reaction principle of double template action was put forward.The results showed that when the reaction temperature was 20 ℃，the concentration of SDS was 0.1 mol/L，the concentration of glutamate was 40 g/L，the reaction time was 2 h，and the pH value was 12.3，the micron grade and smooth calcite spherical CaCO₃ could be prepared，which could provide reference for the industrial production of spherical calcium carbonate.

Key words: calcium carbonate, crystal form control agent, sodium dodecyl sulfate, amino acid