Comparison between the effects of ultrasonic and thermal stimulation on release of internal hydrophobic dyes from Pluronic micelles

• Effect of ultrasonic stimulation on release of dye from micelle was investigated.
• Compared with thermal stimulation, ultrasound is effective for the release of dye from micelle.
• A low ultrasonic frequency is effective for the release of dye from micelle.
• New chemical reaction process using Pluronic micelles as reactant carriers is proposed.

In this study, we propose a novel chemical reaction process using Pluronic micelles as reactant carriers in order to reduce complicated piping. A Pluronic micelle containing the hydrophobic dye NKX-1595 was prepared by a dialysis method, and the release of the internal dye from the micelle by external stimulation was investigated. In particular, we investigated the effects of the combination of ultrasonic frequency and type of Pluronic on degree of dye release (DDR). A low ultrasonic frequency is effective for the release of the internal dye from the micelle and ultrasonic physical effects are an important factor. Furthermore, under a weak ultrasonic physical effect at 490 kHz, the inhibition effect when the internal substance moves to the corona from the micelle core is also important for estimating the retention of the internal substance by the micelle. In addition, we investigated the effects of thermal stimulation on DDR at several environmental temperatures. The internal dye was gradually released from the micelle when the environmental temperature was greater than 303 K. Thus, appropriate design of external stimulation enables controlling not only the amount of effluence but also the release rate of the internal dye from the micelle.