Chapter 10: Not Sticking

There are times when we want to ensure that things don't stick together and other times when we want to remove things that are stuck. To get the desired poor adhesion we simply reverse the principles that give us strong adhesion, though we need to add one more key factor, the no-slip boundary condition that makes cleaning a surface a tough challenge. Now we can make tomato ketchup flow cleanly out of its bottle, make ice slide off a roof and understand why a silicone release liner works. We can lubricate a mechanical joint and can apply the rather different principles of snowboarding to the lubrication of our hip joints. We can understand why food doesn't stick to Teflon, and why Teflon can stick to the pan. We then work out how to unstick stuff – that annoying label, that old paint, grease on our clothes and food from our crockery, learning about the Sinner circle and the choices it offers. Finally we take a look at why it's usually a bad idea to demand that adhesives be removable and/or recyclable.