Mechanical Stability Characteristics of Teflon

Chemistry

• The Teflon molecule is a tough combination of fluorine and carbon atoms, with a high molecular weight (so it's dense) and a low coefficient of friction (so it's slippery). The tightly packed matrix of atoms is also hydrophobic, meaning it repels water. Teflon is a poor electrical conductor or, as DuPont markets it, an excellent insulator.

Properties

• Teflon is chemically inert. At temperatures below 300 degrees Celsius (572 degrees Fahrenheit) it won't dissolve in solvents, including water, the universal solvent. It resists turning brittle at low temperatures, and it won't catch fire at ordinary temperatures. When you hear of someone scorching a Teflon pan left too long on the stove, it's usually the non-Teflon plastic handle that takes the hit.

Uses

• A substance that can be mass-produced with such characteristics has uses far beyond cleaning off a burnt breakfast. Teflon's nonstickiness and heat resistance are put to use in lubricants for high-speed, high-heat electrical equipment. Chemical equipment used to pump corrosives will have Teflon-coated valves. Carpet makers coat their products with Teflon to resist staining. Artificial body parts are made from Teflon, which won't react with the body and can't be destroyed by the body's defenses.

Puzzle Solution

• Sooner or later, everyone asks: If nothing sticks to Teflon, then how come Teflon sticks to pans? It doesn't, at least not very well. DuPont overcomes the nonstickiness mechanical characteristic of Teflon with a combination of manufacturing tricks and chemistry. The tricks include sandblasting the pan beforehand to roughen the surface, which increases its surface area, so more Teflon molecules will stay on the pan, and stay longer. Then DuPont adds a coating of a molecule with sticky properties, the better for Teflon molecules to cling. Finally, a coating of Teflon containing ceramic particles is added, and the sandwich is baked together. Since by "coatings" DuPont means thin sheets of molecules measured in thousandths of an inch, never clean Teflon cookware with anything more abrasive than a rubber spatula or a wet sponge.