イオン性界面活性剤濃度が電界中のマイクロバブル群の移動速度に与える影響

抄録

The effect of ionic surfactant concentration on the migration velocity of microbubble (MB) swarms in an electric field was investigated. Microbubbles were generated in water containing dissolved ionic surfactants using a Shirasu porous glass (SPG) membrane. By dissolving a cationic surfactant, MBs were charged positively, whereas dissolving an anionic surfactant resulted in negatively charged MBs. The charged MB swarms were driven by an electric field in a water tank equipped with electrodes. Their motion was recorded with a high-speed camera, and the migration velocity was calculated from the acquired images by particle tracking. The results showed that the migration velocity increased with the surfactant concentration until it reached the critical micelle concentration (CMC). Beyond the CMC, the migration velocity became nearly constant. This behavior is attributed to the fact that the charge carried by the MBs depends on the amount of surfactant monomers present in the surrounding water.