Honestly wheels depend on friction to move. Without friction they will spin in place. Roller Skates don't rely on friction instead they try to minimise friction due to the accelerating forces being provided by the person. As a result with each stride the wheels want to allow you to go as far as possible without slowing down too much. But roller skates still require a small amount of friction to allow the rider to move at all, if there is no friction the wearer will be unable to apply accelerating forces to themself (without a jet engine or something) and hence will be kicking out their legs unable to do move. Meanwhile if the friction is negative, the wheel will continously spin in place without end or, the wheel will be forced backwards. The negative friction will force it to potentially go the opposite way to which its spin is trying to take it. This is because a forward spin relies on friction to move forward, if friction reverses, so will thy motion.
Ice skates would be best suited to a negative friction.