<scp>CO₂</scp>–switchable surfactant with amino–terminated polypropylene oxide

Abstract CO 2 –responsive surfactants are one of the research hotspots in colloid chemistry, and identifying suitable CO 2 –responsive surfactants is of significant importance. This study investigates the CO 2 –responsive properties of the amino–terminated polyether ZFL–1001 and its potential as a switchable surfactant. The research demonstrates that ZFL–1001 exhibits reversible changes in conductivity, surface tension, viscosity, and emulsion stability when exposed to alternating CO 2 and N 2 conditions. The protonation of secondary amine groups triggered by the introduction of CO 2 enhances hydrophilicity, leading to increased conductivity, reduced surface tension, and the formation of stable micelle networks. These networks significantly influence viscosity and emulsion behavior. Conversely, the removal of CO 2 reverses these effects, returning the system to its initial state. ZFL–1001 also facilitates reversible phase transitions in crude oil emulsions, offering a novel method for emulsion regulation in oil reservoirs. These findings highlight the potential of ZFL–1001 to serve as an environmentally friendly and efficient CO 2 –switchable surfactant for applications in smart materials, crude oil extraction, and emulsion control systems.