pure carbon powder is a black, porous substance that can be made to be magnetic and has other intriguing properties. Physicists are reporting in the journal Nature that the material may hold promise as a tool for making tiny magnetic particles that could be used to create biosensors or drug-delivery carriers that can be directed to diseased tissue. The researchers have made thin films of the material and analyzed them with electron microscopes and x-ray spectrometers. They have seen no signs of impurities that would account for the magnetism, but they admit that much more research is needed before the discovery is considered valid.
The discovery comes as scientists are attempting to develop a new generation of materials that are not only stronger than steel, but also lighter. They are particularly interested in replacing plastics and metals, which are difficult to recycle, with lightweight, green alternatives. Ideally, these materials will also be biocompatible and have the potential to replace synthetic drugs.
When pure carbon is mixed with potassium nitrate, it turns black and is sometimes referred to as gunpowder. The nitrate prevents the formation of electrostatic charges, which reduces the likelihood that a stray spark will ignite the black powder and cause an explosion. Sometimes the black powder is tumbled with graphite, which helps to coat the grains and further prevents them from igniting.
Other uses for carbon black include use as a colorant in rubber, wire cable and tire production, and as an ingredient in inks, paints, coatings, and casting. It is also used in battery manufacturing and as an additive for magnetic tapes and additives. It is an approved organic material for livestock feed and winemaking, and it is used as a soil enhancer, pesticide, and fertilizer. People who have long-term exposure to carbon black may be at risk for lung damage and cancer.