Nanoscale TiO₂/Al₂O₃/TiO₂ Multilayers on Basalt Fiber Fabrics for Structural Color via Atomic Layer Deposition

Continuous basalt fibers (BFs) typically exhibit brown or dark brown coloration, which limits their applications in high-end textiles and decorative materials. To address the issue, this study employed atomic layer deposition (ALD) technology to construct precisely controlled nanoscale TiO2/Al2O3/TiO2 multilayer structures on BF fabrics. By variation of the thickness of the intermediate Al2O3 layer at the nanoscale (37–125 nm), structural colors with different hues were achieved. The colored fabrics demonstrated excellent colorfastness to rubbing (grade 5) and washing (grade 5), attributed to the uniform and dense nanometric oxide coatings formed on fiber surfaces. Notably, they exhibited exceptional lightfastness, achieving the highest grade of 8. The excellent performance originates from the stability of the nanophotonic structure─the color properties persist as long as the layered nanostructure remains intact. This work successfully applies ALD to achieve structural color of BFs, demonstrating an efficient, precisely controlled, and environmentally benign coloring method with potential applications in high-end textiles and anticounterfeiting.