图 书 馆
活性乳液的实验Experiments with Active Emulsions |
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| 课程网址: | http://videolectures.net/kolokviji_herminghaus_emulsions/ |
| 主讲教师: | Stephan Herminghaus |
| 开课单位: | 马克斯普朗克研究所 |
| 开课时间: | 2012-06-13 |
| 课程语种: | 英语 |
| 中文简介: |  |
| 课程简介: | Experiments are presented with emulsions showing various types of 'active' collective behavior. Ensembles of aqueous droplets containing Belouzov-Zhabotinski (BZ) oscillators are shown to exhibit coupling patterns depending on the formation of lipid bilayers between them. We observe target waves, quorum sensing, and spiral waves in two-dimensional rafts of mono-disperse emulsions. As the volume fraction of the dispersed phase (i.e., the droplets) is reduced, we observe self-propelled motion of the droplets, which can be controlled by the BZ reaction if desired. We propose a simple mechanism based on Marangoni stresses which accounts for this motion. Swarming is shown to exhibit pronounced correlation features which depend strongly on the raft density. While the bromine release provides the energy source for this type of self-propulsion, we present an alternative system based on liquid crystals which shows similar collective behaviour, but whose motion has a longer lifetime and is fuelled by the spontaneous formation of a microemulsion. Based on the meso-structure of the liquid crystal, it enables, aside from simple droplet motion, much more complex patterns to evolve, the details of which are yet far from understood. |
| 关 键 词: | “活性”集体行为; 偶联模式; 马兰戈尼应力 |
| 课程来源: | 视频讲座网 |
| 最后编审: | 2021-01-08：yumf |
| 阅读次数: | 77 |