Development of Nanosized Mica Particles from Natural Mica by Sonication/Organic Intercalation Method for Pearlescent Pigment

In this study, the possibility of reducing natural mica particles to nanosizes without damaging its surface properties and smooth flake shape for pearlescent pigment application was investigated by using the sonication delamination method. For this purpose, the layer charge density of the natural mica mineral was reduced using surfactant intercalation followed by maximum exfoliation of mica interlayers with the help of sonication. Therefore, the delamination was achieved in a simple and more energy-efficient way by the sonication process and, in turn, the dimensions of mica were reduced to nanoscale with smooth surface features. With this new delamination process, the lowest particle thickness values were obtained as 0.061 microns after only 1 h sonication period. The results were found to be much significant when compared to the literature. Furthermore, the unique pearlescent pigment properties of mica particles were attributed to the characteristic shape and nanosized mica, which are coated with TiO2.

Preparation and characterization of CuO/Muscovite flakes pearlescent pigment with UV absorption and high NIR reflectance

The CuO nanoparticles were deposited onto muscovite flakes using sol-gel methods. The thermal, conductivity, optic and structural properties of obtained pigments (CuO/Muscovite) were studied. Hence, the prepared pigments were characterized via using scanning electronic microscopy (SEM) and ultraviolet–visible spectrophotometer (UV-Vis). The results show that CuO was coated on the surface of muscovite flakes uniformly. The obtained pigments show the more stable thermal properties than those obtained from undeposited flakes. The CuO/Muscovite pigments showed high ultraviolet shielding performance. In addition that CuO/Muscovite pigments exhibited higher near-infrared (NIR) reflectance than those of pure-CuO.