The 'self-cleaning' technology brings in use titanium dioxide photocatalyst that is when triggered by light it decomposes dirt, stains, and harmful microorganisms.
Wool and Silk are the most valuable and are most commonly used fabrics throughout the world. They are the most esteemed players of Textiles, Garments and Apparels Industry. However, these fabrics are the toughest to maintain and clean. They need numerous efforts for long-life and better quality maintenance over years to protect them from damage.
But there is a reason to cheer because science has come up with a solution for this. The ones who hate washing but are hygiene conscious, self cleaning variety of wool and silk made with the help of nanotechnology can be a nothing less than a boon for them.
Wool and silk hold in them natural proteins called keratins. In the new study, wool fabrics with and without a nanoparticle coating composed of Anatase titanium dioxide is prepared. It is a substance that helps destroying stains, dirt, and harmful microorganisms on exposure to sunlight.
The self-cleaning fabrics work using the photocatalytic
properties of titanium dioxide, a compound used in many new nanotechnology
solar cell applications. The fabric is coated with a thin layer of titanium
dioxide particles that is only of 20 nanometers in diameter. When this
semi-conductive layer is uncovered to light, photons with energy equal to or
greater than the band gap of the titanium dioxide stimulate electrons up to the
conduction band. The energized electrons within the crystal configuration react
with oxygen atoms in the air, creating free-radical oxygen. These oxygen atoms
are potent oxidizing agents, which can break down most carbon-based compounds
through oxidation-reduction reactions. In these reactions, the organic
compounds (i.e. dirt, pollutants, and micro organisms) are broken down into
substances such as carbon dioxide and water. Since the titanium dioxide only
acts as a catalyst to the reactions, it is never used. This lets the coating to
persist breaking down stains over and again.
The researchers stained the fabric sample with red wine. The coated fabric, as expected, showed almost no signs of the red stain, whereas the untreated fabric remained deeply stained, after 20 hours of exposure to replicated sunlight. This non-toxic Titanium coating can be permanently bonded with the fibre without altering its touch and feel. This study shows that self-cleaning fibrous proteins such as wool can be produced by a simple coating process with this OctahedriteTiO2 under mild conditions. A modification of these fibrous proteins with Succinic anhydride acid introduces additional carboxylic groups by process of acylation which allows for improved bonding between TiO2 and the fibers that in turn results in more useful self-cleaning characteristics. The chemical modification and Anatase coating methods do not utilize toxic reagents or solvents and the measures are taken under placid conditions good for such keratinous materials.
The complication in the research was looking out for a way to unite keratin with titanium dioxide. Applying a ceramic inorganic material to organic fibres especially keratin protein fibres such as wool, silk, hemp, and spider silk, was the hardest nut to crack.
After a chemical reaction to "activate" the surface of the fibres, the team found it could make the titanium dioxide crystals stick.
Uses and Benefits
It is expected that as soon as the technology obtains the approval and NOC technically and economically the product will then be easily available in the market. Presently, this patent-awaiting technology is going through its industrial testing and mill checks.
This self-cleaning property will attain a prime position in forthcoming textile scenario and other commonly used materials to maintain hygiene and prevent the dispersion of contagions. Particularly since microorganisms can easily grow on textile surfaces for almost three months, this fabric becomes more necessary.
Self-cleaning technology can also help in reducing the consumption of chemicals, such as detergents and dry-cleaning solvents, water, and energy.
Hence we can see that we will soon get fabrics that will clean off stains and foul smells in the sunshine, themselves. No physical efforts will be required brushing them off over and over again degrading the quality of your costly clothing.