Recent Progress toward Physical Stimuli‐Responsive Emulsions

Emulsion as a fine dispersion of immiscible liquids has involved widespread applications in industry, pharmaceuticals, agriculture, and personal care. Stimuli‐responsive emulsions capable of on‐demand demulsification or changing their properties are required in many cases such as controllable release cargo, oil recovery, emulsifier recycling, and product separation, great progress is achieved in these areas. Among these various triggers, much effort is made to develop physical stimuli, due to the noninvasive and environmentally friendly characteristics. Physical stimuli‐responsive emulsions provide plenty of valuable practical applications in the fields of sustainable industry, biomedical reaction, drug delivery. Here, the recent development in the field of emulsions in response to physical stimuli consisting of temperature, light, magnetic fields, electrical fields, etc., is summarized. The preparation methods and mechanisms of physical stimuli‐responsive emulsions and their applications of catalysis reaction, drug delivery, and oil recovery are highlighted in this review. The future directions and outstanding problems of the physical stimuli‐responsive emulsions are also discussed. In this paper, the recent progress is reviewed on emulsions, whose properties, such as type, stability, droplets' structure, can be altered upon physical stimuli, including light, temperature, magnetic fields, electric fields, ultrasound, and microwave irradiation.