Need a way to demonstrate electrostatic repulsion without a model? This "head of hair" makes a good substitute. Attach the suction cup on the base of the plume to the globe of the Van de Graaff generator. Turn on the machine and watch each strand of "hair" stand away from each other. The reason, of course, is that each strand has the same electric charge and repels its neighbor. With instructions.
A fun accessory for your Van de Graaff generator!