Preparation Process, Surface Modification and Application Progress of Nano-calcium Carbonate

As an important inorganic functional material, nano-calcium carbonate (nano CaCO₃) was proposed in the 1980s and has been widely used in rubber, plastics, medicine, and paper industries because of its high specific surface area, good biocompatibility, and non-toxicity. In recent years, with the rapid development of the demand for nano-calcium carbonate, the research of nano-calcium carbonate at home and abroad has been deepening, and the related nano-calcium carbonate industry has developed quickly. Recently, many groups reported new preparation technologies, such as the physical, carbonization, compound decomposition, and emulsion methods. Among these proposed methods, the intermittent bubbling carbonization method is considered the most widely used classical process in the world. In the modification of nano CaCO₃, the activation mechanism of coupling agents, surfactants, inorganic substances, polymer modifiers, and the modification effects of different modifiers are introduced. In this paper, the new application progress of nano CaCO₃ in papermaking, daily chemical products, biomedicine, plastics, and construction materials is reviewed. In particular, nano CaCO₃ has excellent biocompatibility and low cytotoxicity, which greatly improves the mechanical properties of polymer composites. Finally, the problems to be further solved in the future development of nano CaCO₃ are analyzed and prospected, especially in preparing the high whiteness of nano-calcium carbonate from natural limestone with high iron content (>0.08%).