Teflon Ball

This incredibly slippery and dense white ball is Teflon (PFTE): the same material that coats our non-stick frying pans. A product of the intense materials research that took place during the second world war, Teflon was invented by a chemist at Dupont in the 1930s who was trying to develop a new, non-flammable refrigerant. This newly discovered carbon and fluorine-based polymer was found to be inert, fire-resistant and very resistant to solvents and corrosive chemicals. As a result it was originally put to use by the military in the development of the atomic bomb, where it was used to coat materials that came into contact with extremely caustic uranium hexafluoride. 

Like many of the materials developed during WW2, Teflon later found its true calling in a domestic setting, in our cookware. This slippery customer has an incredibly low coefficient of friction (a measure of how sticky it is in contact with other surfaces) and is also both hydrophobic and oleophobic (repels both water and oil), making it the perfect non-stick surface for cooking on. It can also  self-lubricate, which makes it really useful as a ball bearing or sliding component in corrosive or demanding environments. For the same reasons, biomedical engineers experimented with Teflon as a possible material for the femoral head of hip replacements in the 1960s, but it soon proved unsuitable as the particles produced when it degraded (quite rapidly) caused a massive tissue reaction, and patients had to have a second surgery to replace it.

This particular sample appeared alongside our director Mark Miodownik in BBC2’s 2011 series Wonderstuff, which explored marvellous household materials. At the time Teflon was billed as the world’s slipperiest material, but it has since been surpassed by BAM, a compound of boron, aluminium and magnesium that is heralded as the greatest non-stick material in the world, ‘making teflon look like velcro’.