Preparation and characterization of blue color aluminum pigments Al/SiO2/PB with double-layer structure

► blue aluminum pigments with double-layer coat Al/SiO2/PB was first obtained. ► wet chemical method was used for the PB coating on aluminium pigments. ► CTAB is a good surfactant for the PB coating layer on the surface. ► a smooth PB layer composed of the nanoparticle was formed on Al/SiO2 particle. ► Al/SiO2/PB pigments have angle-dependent optical effects.