An air ioniser (or negative ion generator or Chizhevsky's chandelier) is a device that uses high voltage to ionise (electrically charge) air molecules.
Vitamin E for hair growth is beneficial because vitamin E has the effect of a scalp massage all the time. It contains valuable antioxidants that help to keep the immune system up and improves circulation to all parts of the body, including the scalp.
Vitamin E is essential for all kinds of things to do with the body, so it might make sense that there are many benefits to the hair from vitamin E as well. Recently, it has been found that the use of vitamin E for hair growth might be useful; this is on top of its many other health benefits.