Fabrication of Fe3+ doped Mg/Al layered double hydroxides and their application in UV light-shielding coatings

Abstract

Fe³⁺ doped Mg/Al layered double hydroxides (Mg/Al + Fe LDHs) were prepared by a facile solvothermal method. Incorporation of Fe³⁺ into Mg/Al LDHs can efficiently shift their UV-absorption to cover the entire UV range, allowing them to qualify as a candidate for blocking the whole UV light region (200–400 nm). The as-obtained Mg/Al + Fe LDHs possess intrinsic dispersibility in water, and, moreover, they can be dispersed in an organic solvent (xylene) after being sequentially washed with water/ethanol and then acetone. Accordingly, highly transparent and whole UV-blocking coatings were readily fabricated by incorporating Mg/Al + Fe LDHs into waterborne or solvent-based polysiloxane coatings, or merely using an aqueous Mg/Al + Fe LDH dispersion due to its self-supporting behavior. More importantly, the Mg/Al + Fe LDH-based coatings exhibited long-term UV-shielding performance even after accelerated weathering tests for as long as 800 h.