Mechanochemical preparation and performance regulation mechanism of highly durable and multifunctional iron red nanocomposite pigments derived from natural mixed-dimensional palygorskite clay

Iron oxide red pigments are one of the most widely used inorganic red pigments around the world. It is always pursed to improve their physicochemical properties. Herein, a continuous mechanochemical method was employed to fabricate high-performance iron red nanocomposite pigments via anchoring α -Fe 2 O 3 nanoparticles on the surface of natural mixed-dimensional palygorskite clay (MDPal). The mechanical force of twin-screw extrusion promoted the Si-OH groups of MDPal to coordinate with Fe 3+ to form the precursor, while MDPal was activated with the residual H + of the involved nitrate to accelerate the thermal diffusion of Al 3+ into α -Fe 2 O 3 crystal lattice, thus the nanocomposite pigments presented a bright yellowish-red color ( L ∗ ​= ​35.61, a ∗ ​= ​33.10, b ∗ ​= ​35.86, C ∗ ​= ​48.80). Furthermore, the mixed-dimensional nanostructure of MDPal served as a good substrate for chemical bonding of α -Fe 2 O 3 nanoparticles to improve the dispersion and environmental stability of iron red pigments. Due to the synergistic effect of each component and the excellent thermal and chemical stability, the obtained nanocomposite pigments exhibited excellent application prospect as functional inorganic pigments for anti-corrosion coating, overglaze ceramic and coloring and reinforcing of polypropylene, respectively. It provided a facile strategy for preparation of high-performance multifunctional iron red pigments based on MDPal.