tlema1617 said: How are pans nonstick?
Pans are usually made non-stick using Teflon, the trade name for the polymer polytetrafluoroethene (PTFE). The polymer is a long chain of repeating units, one of which is shown below. Although PTFE is the major polymer used, not all non-stick coatings are necessarily teflon; other fluoropolymers can also be used.
Elemental fluorine is very reactive, but within PTFE, the fluorine atoms have an electron structure that is very stable - as such, they don’t react with other atoms easily. As the carbons in PTFE are surrounded by the fluorine atoms, they are also shielded from reacting. This prevents food from sticking to the pan.
The obvious question to ask is how the slippery non-stick coating can be made to stick to the pan in the first place. The surface of the metal pan must be roughened to make it easier to stick the polymer to it; the teflon is then applied in coats, and baked on to the pan in order to ensure it remains attached. It doesn’t attach to the metal as such, but this process makes it very difficult for it to seep out of the roughened surface of the metal.
You can read more detail here. Hope that answers the question!
Teflon is non-stick not just because of its near-nonexistent reactivity, but also quite interestingly due to the electronegativity of fluorine. The electronic structure of fluorine results in carbon-fluorine bonds having a lot of covalency (electron sharing) but the biggest electronegativity in the periodic table results in one heck of a lot of polarity (uneven electron distribution). Thanks to the molecular geometry of PTFE (Teflon), all these permanent dipoles cancel each other out along the chain very effectively. These bonds are not especially amenable to having their electrons shunted around, and unlike in hydrocarbons, any transient dipoles along the bond for Van den Waals’ forces are pretty pitiful because they essentially get drowned out by the huge dipole moment. The ultimate result is that Teflon molecules don’t actually interact with other molecules or each other very effectively. They have an electron rich outer electron cloud that refuses to budge, and the electro positive core is hard to access by nucleophiles, as they are repelled by the abundant fluorine electrons. The only reason Teflon stays as a solid, is that the chains are so long that they entwine around each other. Ironically, this makes Teflon pretty hard to remove once it’s been successfully deposited onto that roughened pan, unless you heat it until it decomposes: formally, Teflon doesn’t have a melting point, and I have never found a solvent yet that will dissolve it.