Emulsifier is a type of surfactant typically used to keep emulsion (mixture of immiscible fluids) well dispersed. Emulsifiers normally have a hydrophobic (water -hating) and a hydrophilic (water - liking) end. The emulsifiers will surround an oil (or other immiscible molecule) and form protective layer so that the oil molecules can’t clump together. This action helps keeps the dispersed phase in small droplets and preserves the emulsion.
Most of industrial oils in circulation systems require excellent demulsification properties in order to separate water contamination from the lubricating system. Without demulsifiers lubricating oils can form relatively stable water-in-oil emulsions.
