The coating can be applied to clothes, paper, glass and steel and, when combined with adhesives, maintains its self-cleaning properties after being wiped, scratched with a knife and scuffed with sandpaper.
Self-cleaning surfaces repel water but often stop working when they are damaged or exposed to oil. The paint creates a more resilient surface that is resistant to everyday wear and tear, for use in a range of real-world applications from clothing and cars, say the researchers.
First author Yao Lu (UCL Chemistry), said: "Being waterproof allows materials to self-clean as water forms marble-shaped droplets that roll over the surface, acting like miniature vacuum cleaners picking up dirt, viruses and bacteria along the way. For this to happen, the surface must be rough and waxy, so we set out to create these conditions on hard and soft surfaces by designing our own paint and combining it with different adhesives to help the surfaces withstand damage."
Researcher from UCL, Imperial College London and Dalian University of Technology (China) made paint from coated titanium dioxide nanoparticles to give a range of materials self-cleaning properties, even during and after immersion in oil and following damage to the surface.
Different coating methods were used to create the water repellent surfaces, depending on the material. 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 the materials became waterproof and self-cleaning as water droplets of different sizes were seen bouncing instead of wetting the surface, removing the dirt applied by the researchers. This was maintained after damage was inflicted on the surfaces.
The study was published today in Science magazine.
