Studies on Dynamics of Microsphere Suspensions Probed by Dynamic Ultrasound Scattering Techniques

動的超音波散乱法によるマイクロ微粒子懸濁液のダイナミクスに関する研究

2017-03-24

2017-03-24

Particle sizing in highly turbid suspension is one of the most challenging and important subjects in material science. Dynamic ultraSound Scattering (DSS) technique utilizing ultrasound pulse allows us to achieve such demands. Since the speed of ultrasound wave is much slower than that of light, the time evolution of the ultrasound scattering amplitudes and phase can be analyzed. In the previous studies, the advantages were fully utilized, and the diameter and the inter-particle interactions in suspension were successfully evaluated by analyzing the particle velocity. Further, visualization of velocity field was enabled by the phase lock-in analysis. As a result, particle motion as a function of the position and time was evaluated to understand the complex fluid phenomena. For example, cooperative motion of settling particles was successfully observed as a velocity-field image. In order to apply this technique further, I focused to the following four topics: (1) investigation of dynamics of submicron and nano-particles, (2) incident pulse effect on particle motion, (3) sedimentation velocity fluctuations for charged particles, (4) determination of diameter distribution with a novel approach. Through this study, the detectable size was now extended down to nanometer scale. Also, the dynamics of submicron particles exhibiting Brownian motion and sedimentation was investigated in detail.

博士（工学）

京都工芸繊維大学

14303甲第824号

http://hdl.handle.net/10212/2381

eng

ETD

Thesis or Dissertation

Thesis