I was playing around with the high speed camera dropping a ball into water, looking for cavitation. I noticed that sometimes the ball would enter the water without any air bubbles and other times the the ball would generate a huge air bubble. After some experimentation I figured out the difference was whether there were finger prints on the surface of the spheres or not. Take a look at the videos below.
From an earlier post you can see the water wants to wrap around the ball but since the oil is hydrophobic, the water doesn’t adhere to the sphere. This allows air to get drawn into the water with the ball.
You can bet that further fun will be had. Matt and I already have a myriad of experiments in mind so I’m sure you will hear about it later.