6. 単泡性ソノルミネッセンス気泡の観察 : マイクロリアクターの可能性

抄録

Dynamics of a sonoluminescing bubble was observed using a telemicroscope equipped with a video camera and a video recorder. The time resolution was 1/30 seconds, which was far slower than the period of oscillation, i.e., about 30 μs, and yet the observation gave some useful information, in particular, with a help of dust particles of a few μm in diameter which were used as tracers. First, the dust particles, drifting along with a stream, were seen to be scattered by the sonoluminescing bubble. Second, a few drifting dust particles were also seen to be trapped by the bubble, subsequently orbiting around it. The whole behavior suggests that the bubble may eject quadrupolar flows as a jet. The fact that the dust particles can be trapped by the bubble leads to a proposal that the bubble might be used as a micro reactor, where reactants are delivered in micro capsules and forming a dense region surrounding the bubble. This approach has an advantage that the medium, usually water, is little affected acoustically by adding reactants. The plausibility of the approach depends on whether or not there exists the material that is to be broken by Shockwaves emanating from the bubble at the moment of implosion.