Think Big: The world is shrinking

Imagine never having to polish your shoes again, having glistening white teeth without visiting a dentist or owning a mobile phone powered by a miniature battery. These are not just idle fantasies, but a reality where small things could make your wildest dreams come true.

A band of scientists believe they can push the boundaries of chemistry and physics to create a host of tiny particles that could revolutionise products we use every day. Welcome to the wonderful world of nanotechnology.

You may already be digesting and using nanoproducts without even knowing it. Fizzy drinks and fruit juices get their neon rainbow of colours from tiny particles that dissolve in liquid and disappear without a trace. Many vitamins are insoluble in water but can be added to food by making them into particles smaller than the eye can see. Cosmetics such as sunscreen are made of miniparticles that act as miniature solar soldiers that absorb harmful ultraviolet light to protect your skin from the sun.

At a recent conference in Mannheim, Germany,scientists working at the chemical company BASF presented a huge range of products that could soon be out on supermarket shelves to make our lives easier. In a fastmoving world where things change daily and the pressure to keep up is immense,thinking small may be the solution.

Nanotechnology has been heralded as one of the key technologies of the 21st century. By manipulating particles 50,000 times smaller than a human hair, materials can be merged into products or can create new properties.

Manufactured products are made from atoms. Their properties depend on how the atoms are arranged. What nanotechnology does is build things one atom at a time to create a myriad novel molecular goods possessing amazing properties. The magical trick is to manipulate the molecules individually and place them where they are needed to make the right structure. Nature has played an inspirational role in pushing this mini-world forward.

The leaf of an exotic flower inspired the creation of a miracle spray that refuses to let dirt stick to shoes. The lotus flower from Asia has leaves with a strange arrangement of wax crystals on its surface that repel water. This structure creates a jagged texture on the leaf like a row of pointed teeth that water drops roll off. As the liquid rolls over the leather, it takes any dust or dirt along for the ride leaving your shoe spotless.

Harald Keller,a polymer scientist at BASF, has trapped this lotus effect in a can. Once you apply the lotus spray it dries into the leather and takes on an arrangement similar to the leaves.

This spray is easy to apply and the more porous a substance is the more successful it will be. I believe that with improvements this spray should conceivably last a few years before having to be reapplied,says Keller. It could also be used on building materials,paper and textiles.

It is not only your footwear that benefits from the wonders of the nanoworld. The effect that film stars get from teeth bleaching to blind us on-screen could soon be available in a humble tube of toothpaste. At the moment every time you brush your teeth you damage the enamel. This latest idea is to rebuild the attacked enamel using nanoparticles incorporated in toothpaste that seals pores and restores the natural whiteness of the teeth,says Ralf Norenberg,from the performance chemical division at BASF.

But after a stream of different whiteners that are on the market to brighten teeth,why should we believe this new product works? Norenberg made tiny particles of hydroxyapatite, which has the same chemical structure as tooth enamel. He found that when applied to teeth it creates a protective coating that sticks firmly and does not allow dirt to invade. The key lies in the unique shape of the apatite particles.

This material forms a suspension of rod-shaped crystallites that ensures the teeth get allover smooth cover and demonstrates flawless organisation, claims Norenberg. Other products currently on the market are not as effective and use optical brightness which paints your pearly whites, causing pimples to form that allow bacteria to settle and breed on the surface.

The miniature wonderworkers do not stop there. In a world driven by technology there is always a need to create and store information more efficiently. As your mobiles and laptops get smaller their source of power needs to do the same. A revolutionary nanocube that can store hydrogen may solve this problem. Hydrogen gas is cumbersome to store and carry around which makes it impractical to use in mobile phones where space is crucial.

These cubes,combining the features of both PET drink bottles and sun cream terephthalic acid and zinc oxide Ñhave a huge range of applications. The high surface area and porous nature of these cubes allows them to adsorb hydrogen and release the gas as energy when a rapid drop in pressure occurs.

As they are rechargeable, they could replace conventional batteries and storing the gas in a container the size of a cigarette lighter would mean they could power small portable appliances for up to 10 hours. Nanocubes could be a big breakthrough for laptops and mobiles.


Clodagh O'Brien won the older category of The Daily Telegraph BASF Science Writer awards last year. This year's search for the young stars of science writing was
recently launched by the author Fay Weldon.

To find out more, call 020 7704 5315; e-mail
[email protected]; go to www.science-writer.co.uk; or write to The Daily Telegraph BASF
Science Writer Awards 2003,
4 Hanover Yard, Noel Road,
London N1 8YA

By building things one atom at a time you create a myriad
goods possessing amazing properties

15 Jan 2003