Analysis of Nonlinear Dynamics of Microbubbles Considering Adsorption and Desorption of Surfactant

考虑表面活性剂吸附和解吸的微泡非线性动力学分析

• 批准号: 17560158
• 负责人: TAKAHIRA Hiroyuki
• 金额: $ 2.24万
• 依托单位: Osaka Prefecture University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560158/
• 关键词: Microbubble; Surfactant; Surface Tension; Adsorption; Desorption; Permeation Resistance; Deformation; Multilayers; Equilibrium Radius

The shrinkage and growth of microbubbles that were trapped with laser-trapping technique or attached underneath a cover glass were observed with a CCD camera. The influence of gas diffusion was investigated for two kinds of surfactant microbubbles; one was Levovist and the other was Imavist. Two kinds of equilibrium radii were observed for laser-trapped shrinking microbubbles. The first one was related to the equilibrium surface concentration of surfactant. The other was related to the decrease of the surface tension due to the compression of the surface area at the maximum surfactant concentration. It was shown that when the ambient liquid pressure increased, a tiny microbubble shrank accompanied with large surface deformation, and did not return to the initial size even after the pressure was reduced. On the other hand, a large microbubble shrank nearly spherically. The depression of bubble surface suggests the formation of multilayers of surfactant or lipid on bubble surface. It was also shown that air diffusion enhanced the growth of the Imavist.A bubble model was also constructed by considering the adsorption/desorption of surfactant, the dynamic surface tension, and the gas permeation resistance of surfactant or lipid layers. The profiles of laser-trapped microbubbles were compared with simulations based on the model. The simulations with the dynamic surface tension agreed with the experimental results. The simulations showed that the rate of adsorption of surfactant was much faster than the shrinking speed of microbubbles. The decrease of surface tension due to the decrease of the surface area of a microbubble was a significant factor to determine the bubble profile. The simulations considering the gas permeation resistance were in good agreement with the experiments for nearly spherical bubbles attached to the cover glass. The results also showed that the increase of the permeation resistance during bubble shrinkage stabilized microbubbles.

用激光捕获技术或附着在盖子玻璃下的微气泡的收缩和生长，用CCD摄像机观察到。考察了两种表面活性剂微泡对气体扩散的影响，一种是Levovist，另一种是Imavist。观察到了激光捕获收缩微泡的两种平衡半径。第一个影响因素与表面活性剂的平衡表面浓度有关。另一个原因与表面活性剂在最大浓度下的表面积压缩导致的表面张力降低有关。结果表明，随着周围液体压力的增加，微气泡收缩，表面变形较大，即使在压力降低后，微气泡也不能恢复到初始尺寸。另一方面，一个大的微气泡缩小得几乎是球形的。气泡表面凹陷表明气泡表面形成了多层表面活性物质或类脂。考虑表面活性物质的吸附/脱附、动态表面张力以及表面活性物质或脂膜的气体渗透阻力，建立了气泡模型。利用该模型对激光捕获的微气泡进行了数值模拟，并与模拟结果进行了比较。动态表面张力模拟结果与实验结果吻合较好。模拟结果表明，表面活性剂的吸附速度远快于微泡的收缩速度。微泡表面积减小导致的表面张力降低是决定气泡形状的重要因素。考虑气体渗透阻力的数值模拟结果与附着在盖板上的近球形气泡的实验结果吻合较好。结果还表明，气泡收缩过程中渗透阻力的增加稳定了微气泡。

项目成果

Dynamics of Laser-Trapped Microbubbles

激光捕获微泡的动力学

• 发表时间: 2006
• 期刊: The Journal of the Acoustical Society of America 120-5 (Pt 2 of 2)
• 作者: H.Takahira;D.Ito;T.Katsuyama;伊藤大志;勝山友晶;Hiroyuki Takahira;伊藤大志;Dishi Ito;伊藤大志;Hiroyuki Takahira
• 通讯作者: Hiroyuki Takahira

Some Applications of Laser Trapping on the Dynamics of Microbubbles

激光捕获在微泡动力学中的一些应用

• 发表时间: 2004
• 期刊: Proc.Japan-US Seminar on Two-Phase Flow Dynamics Vol.1
• 作者: H.Takahira;T.Nagata;T.Hozumi
• 通讯作者: T.Hozumi

動的表面張力を考慮したマイクロバブルの安定性に関する解析

考虑动态表面张力的微泡稳定性分析

• 发表时间: 2007
• 期刊: 日本機械学会関西支部第82期定時総会講演会講演論文集 074-1
• 作者: Y.Kurosaki;T.Matayoshi;K.Sato;伊藤大志;勝山友晶
• 通讯作者: 勝山友晶

Effects of Dynamic Surface Tension and Gas Permeation Resistance on the Stability of Microbubbles

动态表面张力和气体渗透阻力对微泡稳定性的影响

• 发表时间: 2007
• 期刊: Proc. 5th Joint ASME/JSME Fluids Engineering Conference CD-ROM (FEDSM2007-37514)
• 作者: Y.Kurosaki;T.Matayoshi;K.Sato;伊藤大志;勝山友晶;Hiroyuki Takahira
• 通讯作者: Hiroyuki Takahira

圧力変動下におけるマイクロバブルの安定性に関する実験的研究

压力波动下微气泡稳定性的实验研究

• 发表时间: 2006
• 期刊: 日本機械学会関西支部第81期定時総会講演会講演論文集 064-1
• 作者: H.Takahira;D.Ito;T.Katsuyama;伊藤大志;勝山友晶;Hiroyuki Takahira;伊藤大志
• 通讯作者: 伊藤大志