Nanotechnology making yachts greener
by Richard Boggs
Nanotechnology is poised to considerably bring down the costs of maintaining and operating superyachts.
‘Nano’ is a derivation of the Greek word for ‘dwarf’. Nanotechnology is the synthesis, design and application of materials as small as a few atoms in length or width. As a measure of size a ‘nano’ refers to a nanometre or one-billionth of a metre. In comparison, a strand of human hair is about 60,000 nanometres in diameter.
While nanomaterials and nanostructures are nothing new. What is new is the technology that allows scientists and engineers to manipulate atoms and molecules, arranging them to produce some remarkable, useful products.
One of the areas where nanomaterials are generating tremendous interest in the yachting industry is paints and coatings. On microscopic inspection, even the best multi-component finish is a Martian landscape of craters and valleys. Each imperfection of this visually perfect finish is a trap for the natural nanoparticles found in airborne contaminants such as smoke. Water molecules in the air quickly penetrate the finish, and sooner than any owner desires the bill for another million in paint work seems to be due.
But nanotechnology provides a new box of tools that promises to extend paint life and reduce hull maintenance beyond anything ever before imagined.
Because nanoparticles are so small, some scientists consider them as a distinct state of matter with their own unique properties. In the simplest sense, they can function as crack fillers or barrier materials. Fundamentally, the particles each exhibit electrical charge properties that produce an attraction far stronger than the much larger particles that make up standard paints or coatings.
Nanoparticles can make paint cling to itself and the hull the same way a gecko clings to a window. This unique phenomenon actually makes some coatings “self healing” in that minor physical damage such as scratches or abrasions will use natural forces to restructure the damaged area and restore finish and corrosion resistance.
Confucius said, ‘Be a lotus.’ That advice was based on one of that plant’s most remarkable characteristics – no matter how dirty its surroundings, the first drops of rain wash it immaculately clean. For thousands of years, no one, scientist or philosopher, was able to explain this.
Thanks to the scanning electron microscope, scientists discovered that a lotus leaf (and a butterfly’s wings) maintains its squeaky clean surface by keeping water and dirt at arm’s length. The surface of a lotus leaf is covered with nano-sized water-repellent bumps and a waxy material that prevents moisture from wetting the leaf. Dirt and other contaminants, including bacteria, adhere to the water droplets and are held away from the leaf’s surface.
This phenomenon has tantalized materials scientists, but only recently has nanotechnology provided materials that can duplicate the lotus’s self-cleaning properties.
While truly self-cleaning paints won’t be reducing a deckhand’s workload in the very near future – lotus-like coatings currently available are easily damaged by abrasion, even oily fingerprints – there are easy-to-clean coatings available now.
Rather than holding water and dirt away from the surface, they coat the surface with a layer of nanoparticles that fill all the peaks and valleys found on even the smoothest looking surface. Although not self-cleaning, the water and labour required to remove what little dirt does adhere is greatly reduced compared to standard coatings and they are just as durable.