Effects of bovine serum albumin on a single cavitation bubble

- Unlike other surfactants, BSA improves the SBSL and bubble dynamics.
- A viscoelastic model is modified to characterize the bubble dynamics.
- The experimental data and model calculations reach a good consensus.

The dynamics and sonoluminescence (SL) of a single cavitation bubble in bovine serum albumin (BSA) aqueous solutions have been experimentally and theoretically investigated. A phase-locked integral imaging has been used to record the bubble pulsation evolutions. The results show that, under the optimum driving condition, the endurable driving pressure, maximum radius, radius compression ratio and SL intensity of the cavitation bubble increase correspondingly with the increase of BSA concentrations within the critical micelle concentration, which indicates that the addition of BSA increases the power capability of the cavitation bubble. In addition, BSA molecules dampen the interfacial motion, and especially the rebounds of the bubble after its collapse. BSA molecules modify the dilatational viscosity and elasticity of the bubble wall. A viscoelastic interfacial rheological model that mainly emphasizes on the description of the bubble wall has been introduced and modified to theoretically explain the measured bubble dynamics. A good consensus between the experimental observation and model calculation has been achieved.