Anionic bitumen emulsions carry a negative charge on the bitumen droplets, while cationic emulsions carry a positive charge. This difference affects how they interact with aggregates during application. Anionic emulsions are compatible with aggregates that have a positive surface charge, whereas cationic emulsions are suited for negatively charged aggregates. Cationic emulsions tend to break and set faster due to the electrostatic attraction with most aggregates, which are typically negatively charged. The choice between anionic and cationic emulsions depends on the type of aggregate and desired setting time.