Team of researchers, led by scientists from University College London, developed paint that is not only self-cleaning, but maintains this quality after extreme abuse. It can be wiped, scratched with a knife and scuffed with sandpaper and will still maintain its properties. It can be applied to clothes, paper, glass and steel and will be very useful in many different applications and industries.
Most of self-cleaning surfaces work by being extremely hydrophobic. It means, they are repellent to water but often stop working when they are damaged or exposed to oil. The new paint is much more resistant to everyday wear and tear and creates a more resilient surface. Water droplets just run off of it, picking up dirt, viruses and bacteria along the way.
For a surface to be water repellent and self-cleaning it has to be rough and waxy. To make it more durable, scientists mixed new paint with different kinds of adhesives to help the surfaces withstand damage. Paint itself is made from coated titanium dioxide nanoparticles and can create self-cleaning properties that withstand immersion in oil and damage to the surface.
It is also very important how paint is applied. Therefore, scientists used different methods to coat different materials. An artist’s spray-gun was used to coat glass and steel, dip-coating for cotton wool and a syringe to apply the paint onto paper. All these materials developed water repellent properties and became self-cleaning, as water droplets of different sizes were seen bouncing instead of wetting the surface, removing the dirt applied by the researchers. These properties were maintained even after the abuse these surfaces were presented to.
The results were fascinating. Cotton-wool can fully maintain its pristine white colour even after dipped into blue coloured water. Paper remains clean too after being exposed to dirt and water. In real life it can have number of applications and can make life easier for millions of people. For example, it could be applied to cars to make them hydrophobic and extremely easy to wash. That is why durability is important – scientists want to make sure that car paint with such properties would remain fully self-cleaning even after some scuffing and scratching that cars usually get.
Sounds like a story from a very distant future? It may be reality of tomorrow. Scientists achieved such properties by combining their water repellent paint with different adhesives to make them durable and not as easily rubbed off as today’s hydrophobic coats. And since all materials used are readily available it is not hard to scale up this method for industrial use.
How people could benefit from such innovative hydrophobic coats? Self-cleaning cars that are clean just after washing it with a hose, always clean mobile phones, windows and many other things. However, we will have to wait and see if manufacturers are going to be interested in this technology and if they are going to start applying it to their own products in near future.