Halloysite Nanotubes Modified with Nanoparticles of Cerium Oxide for Health Technology

Abstract

Nanoparticles of cerium oxide have been found to possess UV blocking properties, making them a potential replacement for TiO₂ and ZnO in UV-protection formulations. To further enhance their stability and immobility, we synthesized and deposited such nanoparticles on halloysite nanotubes (HNTs) by reacting Ce(NO₃)₃ and NaOH in aqueous solutions without stabilizers at room temperature. The nanoparticles were <5 nm. X-ray and electron diffraction analyses confirmed that the cerium dioxide (CeO₂, ceria) had cubic crystals. With electron microscopy it was shown that the CeO₂ particles were evenly distributed on the HNTs, resulting in low particle agglomeration. The size of the particles correlated linearly with the oxide content in the nanocomposites up to an oxide concentration of 5%. These synthesized nanomaterials were then used to create sunscreens.