I've recently had surgery on my feet, and my surgeon has just recommended these "miracle patches" to wear over the scars that will reduce them by a signifcant amount.  From googling the brand name, I've found that the only active ingredient in them is silicone.  What does silicone do to the scars that helps the healing process so much?

My partner swims in an indoor heated chlorinated pool most days. Her swimming cap (pictured) lasted about a year before ripping, but over that time it developed these hard brown growths. They cannot be rubbed or scratched off, and seem to be part of the cap material in some way. What are they? The cap is 100% silicone, was washed with liquid soap every day, and hung to dry in a mesh bag in her car between swims.