Photocatalytic self-cleaning keratins: A feasibility study

Area of Science:

• Materials Science
• Nanotechnology
• Textile Chemistry

Background:

• Protein-based materials like wool are susceptible to photodegradation and have limited chemical resistance.
• Developing durable and effective self-cleaning coatings for natural fibers is a significant challenge.
• Photocatalytic coatings offer potential for enhanced material functionality.

Purpose of the Study:

• To synthesize anatase nanocrystals and deposit them onto wool fibers using a sol-gel process.
• To investigate the impact of different acid catalysts (nitric vs. hydrochloric acid) on sol properties and wool compatibility.
• To evaluate the photocatalytic self-cleaning activity and durability of the coated wool fibers.

Main Methods:

• Sol-gel synthesis of titanium dioxide precursor using nitric acid (oxidizing) and hydrochloric acid (non-oxidizing) catalysts.
• Characterization of sol size distribution and crystallinity using X-ray diffraction and photon correlation spectroscopy.
• Assessment of wool fiber photodegradation, surface morphology, UV absorption, mechanical properties, and self-cleaning efficacy (stain degradation, colorant decomposition).

Main Results:

• Successful synthesis and deposition of anatase nanocrystals on wool fibers with good compatibility.
• The choice of acid catalyst significantly influenced sol properties and the degree of wool photodegradation.
• Coated wool fibers exhibited significant photocatalytic self-cleaning activity and improved UV absorption.

Conclusions:

• The sol-gel method is effective for creating photocatalytic self-cleaning wool textiles.
• Careful selection of acid catalysts is crucial for balancing nanocrystal formation and preserving wool integrity.
• The developed coating enhances wool's functionality without compromising its mechanical properties.