Tyres & Rubber

Safe in the overtaking lane with zinc oxide in your tyres

In motor racing, tyres can make the difference between victory and defeat. In everyday life, tyres are key to achieving greater safety, better handling and durability: they must provide suspension, shock absorption, and ensure good tracking and optimal radial run-out. Above all, tyres must be capable of transmitting high forces both longitudinally and transversely to guarantee safe holding on the road – even when the road provides poor grip, is wet, slippery or covered in ice or snow. Tyres run well and reliably with zinc oxide. Zinc oxide improves safety by giving the tyre better crosslink density, thus improving strength and increasing resistance to ageing. A standard car tyre contains around 180 g of zinc oxide.

More than 150 different materials are used to manufacture a tyre. At the beginning of tyre production, there is a rubber mixture consisting of basic substances such as India rubber, fillers, sulphur and numerous chemical additives. To achieve permanent elasticity – the rubber should return to its original position following exposure to mechanical stress – vulcanisation is used. The vulcanisation process generates a network by the cross-linking of polymer chains and it is this network which gives the mixture its required strength. This gives rise to a highly elastic and tensile material – India rubber is transformed into industrial rubber.

The chemistry of this process is highly complex since a number of reactants are involved: Sulphur is relatively inert, which means that vulcanisation proceeds slowly, even at high temperatures; using sulphur alone would lead to a much lower number of crosslinks. The connections would also be chemically less stable. This could result in insufficient strength and reduced ageing stability.

For this reason and since some time back in 1900, India rubber has been cross-linked not just with sulphur, but also with a range of additives which, although these constitute a low percentage only in terms of weight, significantly improve tyre quality. One of these additives is zinc oxide. As a catalyst, it speeds up the vulcanisation process and increases the number of crosslinks per unit of volume (crosslink density). The addition of zinc oxide therefore increases the efficacy of the catalyst, makes the manufacturing process more efficient and guarantees optimal tyre strength. This makes zinc oxide an irreplaceable material as it is essential not least for durability, safety and good grip.

In collaboration with:
ZINC INITIATIVE  part of GDB e.V.network (Metals Trade Association]

Hansaallee 203
40549 Düsseldorf

Tel.: 0211 94 1906-73
E-Mail: info@zink.de
www.zink.de

Ceramic & Glass

ZnO increases the elasticity and reduces fusion point of frits and glazes.

A very important use of zinc oxide is in glass and ceramics. It represents a key ingredient in the production of ceramics wall, floor tiles, artistic glass and table and cooking ware because it lowers melting temperature and thermal expansion or contraction. It also gives high brilliance and luster while improving chemical stability.

Zinc oxide tends to increase the chemical durability of silicate glass. It is used in phosphate glasses, chemically resistant glass wares, glass metal seals and certain fiber glass compositions. It is also used as stabilizer for cadmium sulphide and cadmium selenite during heat treatment, allowing the glass to retain its yellow or red color.

Additionally, zinc oxide is widely used in enamels. It regulates the expansion coefficient, improves glaze and texture and also enhances opacity and whiteness. Furthermore, it is used in porcelain enamel frits, and in glazes for pottery and sanitary ware.

Nutrition

Adding zinc oxide to fertilisers ensures consumers get more zinc in their diet, improving public health on a global scale

Zinc deficiency in people and plants is a global nutritional problem with significant health, social and economic implications.
Zinc deficiency causes health complications such as impaired immunity and cognitive function. It is also characterised by stunting, lack of normal sexual development, poor immune response, skin disorders, and anorexia.

While your body already contains around two to three grams of zinc, it is recommended adult men have an extra 15 milligrams of zinc a day, and women 12 milligrams. According to the World Health Organization (WHO), zinc deficiency is the fifth leading cause of death and disease in developing nations.

It is also estimated that around half of all agricultural soils are zinc deficient, impacting crop production and nutritional value. Given that 70% of the daily calories intake in developing countries comes from cereal-based foods that are low in zinc, it is little wonder deficiency is so prevalent. Adding Zinc Oxide to fertilisers improves the health and production of crops. It also helps plants to better tolerate drought, heat, salinity, and other stressors. And it means farmers make more money from higher yields. It also ensures consumers get more zinc in their diet, improving public health on a global scale.

For millions of people around the world, a few extra milligrams of zinc each day can mean the difference between illness or death, and a healthy productive life. By boosting crops with zinc, we can help address this global crisis.

Pharma & Cosmetics

One of the most popular uses of minerals like zinc oxide is in cosmetics and healthcare products

One of the most popular uses of zinc oxide is in sunscreens and healthcare products. Zinc oxide is used in sunscreen to block UVA and UVB rays, toothpastes, deodorants, baby ointment, and healthcare cosmetics. Think mineral makeup, and skin and hair products.

People with sensitive skin or allergies may prefer mineral cosmetics, because they are made without many allergens, preservatives and perfumes. Better still, foundation with zinc oxide makes the skin look smoother due to its light-reflective properties. It also blocks harmful UV rays, and soothes sensitive skin. Zinc’s beautifying qualities go beyond foundation. It makes your hair glossier and fingernails stronger.

It is also added to pharmaceuticals such as anti-fungal creams and medicinal tapes. And in the form of zinc oxide, it is an active wound treatment thanks to its antiseptic and disinfectant properties. It also ensures any injuries and inflammation heal faster without skin irritation.

Chemicals

Researchers are also looking at how to use nanoscopic Zinc Oxide to generate efficient catalysts with a longer life.

With its unique chemical and electronic properties, Zinc Oxide plays an important role in making catalytic converters. These devices turn toxins into harmless gases, and are used to make plastics, pharmaceuticals, and fuel to run your car.

Specifically, Zinc Oxide is used to make copper-zinc catalysts, which help produce hydrogen and methanol. These have been around since 1922, when a German chemical company used the catalyst for the first time. The device has been used in England since 1966.

Today, the focus is on improving the technology – especially given the increasing scarcity of resources, and tougher environmental protection regulations. Many university and industrial projects are investigating how to use methanol to obtain hydrogen for fuel cells cheaply.

Researchers are also looking at how to use nanoscopic Zinc Oxide to generate efficient catalysts with a longer life. Why? Because developing the best possible catalyst requires the perfect composition and manufacturing process, and the best possible quality and quantity of Zinc Oxide.

Electronics

Small, smaller, smallest – miniaturisation is trending in research and development. And Zinc Oxide nanowires are playing a part, especially when it comes to power generation for the future

POWER SHIRTS

Zinc Oxide has also been used to make shirts that power digital devices. A research team from the Georgia Institute of Technology in the United States, and Samsung Electronics in South Korea, used Zinc Oxide nanowires as electrodes to make a flexible energy storage device. This is called a fibre-based electrochemical micro supercapacitor.

Why use Zinc Oxide? Because it can be grown in any form on any carrier material at low temperatures (below 100°C), and is biocompatible and eco-friendly. The prototype shows that just your heartbeat or footsteps, or even a light breeze, is enough to move the nanowires and generate electricity to charge your mobile devices.

A NEW GENERATION OF LEDS

Power shirts may be a long way off, but LED technology continues to soar. From the red light on your remote control to traffic lights, LEDs are useful everywhere. And now the search is on for an even more eco-friendly generation of lighting.
The ‘NaZOLED’ project, uses Zinc Oxide nanowires to make LEDs. For the first time, this new technology makes it possible to produce substantial components of semiconductor devices from this low-cost, harmless, and stable material. Compared with conventional processes, the material and production process are more cost-effective and safer.

NANOWIRES THAT GENERATE ELECTRICITY POWER YOUR PHONE WITH THE ENERGY GENERATED FROM TYPING A TEXT MESSAGE

Those nanowires could even help unlock the human body as an energy source, using low frequency vibrations. Zinc Oxide nanowires are electrically conductive and have a diameter of 1/5000th of a human hair. When exposed to the slightest mechanical movement (such as a heartbeat, vibrating vocal chords, or moving fingertips) they can generate electricity. So you could power your phone with the energy generated from typing a text message.

Paint & Coatings

Zinc Oxide improves paints & coatings

Zinc Oxide in paint and coatings represents a major application in the industry. Paints containing zinc oxide powder are used as anticorrosive coatings for metals because it provides long-term protection. Coatings formulated with zinc oxide improves colour retention and durability properties.

Zinc oxide paints are particularly useful for galvanized iron. Such surfaces are difficult to protect because their reactivity with organic coatings causes brittleness and lack of adhesion. Zinc oxide paints retain their flexibility and adherence on such surfaces on the long term.

It also protects steel structures under normal atmospheric conditions, as well as steel surfaces under subsea conditions.

Plastics

Solar Power

Researchers are experimenting with Zinc Oxide as a semiconductor to generate energy from the sun.

German researchers at the Energy Research Centre of Lower Saxony (EFZN) are experimenting with Zinc Oxide as a semiconductor to generate energy from the sun. The ‘NanoSol’ project aims to develop new white light sources and photovoltaic (PV) devices, since current solar cells have their drawbacks.

To do this, researchers are using Zinc Oxide nanowires with polymer coatings. Because the nanowires are monocrystalline, they are better at transferring electrons in optoelectronic parts such as solar cells. While more research is needed, the NanoSol project aims to convert almost 100% of energy into light – compared to 70%-80% in normal lamps.

Zinc Oxide is also the focus of a project called ‘NEPHOS’. A decade ago, a team of researchers from Harvard University wanted to increase the energy from lightsensitive materials. They fired laser pulses at the surface of a silicon wafer, in a sulphurous atmosphere. The material turned dark, earning it the name ‘black silicon’. It reflects less incident light than normal silicon – 5% compared to 30%. And once sulphur is added, the black silicon converts invisible infrared light into electrical energy. This change in band structure means a larger range of the solar spectrum is absorbed, used to generate electricity in solar cells. It is thought this could work on less costly materials than silicon, such as Zinc Oxide.