Photocatalytic self-cleaning keratins: A feasibility study

• Published in: Acta biomaterialia 2009, Vol.5 (1), p.50-56
• Main Authors: Tung, Wing Sze, Daoud, Walid A.
• Format: Article
• Language: English
• Subjects: Acid catalysis; Biocompatible Materials - chemistry; Catalysis; Feasibility Studies; Hydrochloric Acid - chemistry; Hydrolysis; Keratins - chemistry; Nanocoating; Nanostructures - chemistry; Nanotechnology - methods; Oxygen - chemistry; Phase Transition; Photocatalysis; Photochemistry - methods; Self-cleaning; Stress, Mechanical; Titanium - chemistry; Titanium dioxide; Ultraviolet Rays; X-Ray Diffraction
• ISSN: 1742-7061; 1878-7568
• DOI: 10.1016/j.actbio.2008.08.009

Anatase nanocrystals were successfully synthesized and deposited on protein keratin-type wool fibers with good compatibility and significant photocatalytic self-cleaning activity using the sol–gel process. Due to the low chemical resistance and liability to photo-degradation of protein materials, the effect of the acid catalyst used in the sol synthesis was studied. The sols were prepared using oxidizing and non-oxidizing catalysts, nitric acid and hydrochloric acid, respectively, for the hydrolysis and condensation reactions of the titanium dioxide precursor. The size distribution and crystallinity of the sols were characterized by X-ray diffraction spectroscopy and photon correlation spectroscopy. The compatibility of sol formulations and wool is thoroughly compared and discussed by analyzing fibers photo-degradation, surface morphology and self-cleaning properties including stain degradation and colorant decomposition. The UV absorption and mechanical properties of wool fibers before and after coating are also discussed.