Preparation of CaCO3/TiO2@SiO2 pigments by the one-pot method: Surface-coated SiO2 improves the weatherability of pigments

In this paper, a CaCO 3 /TiO 2 @SiO 2 composite pigment (CTS) was prepared by a carbonation reaction using a one-pot method. CTS can reduce the amount of rutile TiO 2 needed and improve the weatherability compared with TiO 2 and CaCO 3 /TiO 2 (CT). The performance test results showed that the composite pigment with 60% TiO 2 has a coating film contrast ratio of 91.05% of pure TiO 2 , and the oil absorption and whiteness values were also close to those of pure TiO 2 , indicating that the CTS has good pigment properties. The XPS and infrared results showed that the bonding of CaCO 3 , TiO 2 , and SiO 2 occurred at the interface. The tight bonding of the three substances was realized through a dehydroxylation reaction on the surface. In addition, the SiO 2 layer weaken the photocurrent response of TiO 2 in the CTS and reduced the UV absorption of the composite pigment, which slowed the degradation rate of rhodamine B in the composite pigment coatings; thus, the CTS exhibits excellent weatherability performance in coating applications.