自驱动Janus微球的分数Brownian运动研究

李斐; 张鸿雁; 武美玲; 郑旭; 崔海航

doi:10.3879/j.issn.1000-0887.2014.06.008

自驱动Janus微球的分数Brownian运动研究

doi: 10.3879/j.issn.1000-0887.2014.06.008

¹西安建筑科技大学环境与市政工程学院, 西安 710055;²中国科学院力学研究所非线性力学国家重点实验室, 北京 100190

基金项目: 国家自然科学基金(21005058;11272322;11202219);高等学校博士学科点专项科研基金(20106120120011);陕西省教育厅专项科研计划项目(11JK0530)

详细信息

作者简介:
李斐（1989—），女，陕西咸阳人，硕士生(E-mail: ranxing310@126.com)

中图分类号: O363.1
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- 文章访问数: 1181
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- 被引次数: 0
出版历程
- 收稿日期: 2013-01-16
- 修回日期: 2014-04-03
- 刊出日期: 2014-06-11

Study on Fractional Brownian Motion of Self-Propelled Janus Microspheres

¹School of Environment and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, P.R.China;²State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, CAS, Beijing 100190, P.R.China

Funds: The National Natural Science Foundation of China(21005058;11272322;11202219)

摘要

摘要: Janus微球是形状规则但表面构成不同的特殊颗粒.在PIV实验平台上，以Pt-SiO₂型Janus颗粒（φ=1μm，φ=2μm）为研究对象，获取了通过非对称催化分解H₂O₂产生自驱动情况下颗粒的不规则运动轨迹，通过统计得出不同观测时间下Janus颗粒在不同浓度H₂O₂溶液（0%，2.5%，5%，10%和15%）中的Hurst指数，实验清晰地表明了颗粒轨迹所具有的无规则运动与定向运动的叠加以及反常扩散特征.随后将这一复杂运动分解为随机的Brownian（布朗）运动、自驱动及随机转动的共同作用，并得出了不同因素所主导的特征时间尺度，合理地解释了所观察到的现象.
- Janus微球 /
- 自驱动 /
- Brownian运动 /
- Hurst指数 /
- 分形
Abstract: Janus microspheres are a special class of particles with regular shape but irregular surface composition. On the PIV experimental platform, a selfpropulsion experiment about Pt-SiO₂ Janus microspheres with 1μm and 2μm diameters was carried out. The stochastic trajectories of the particles selfpropelled by the asymmetrical catalytic decomposition of H₂O₂ were obtained. The Hurst indexes related to different observation time intervals were calculated through statistic analysis of the particles suspended in different concentration (0%, 2.5%, 5%, 10% and 15%) solutions. From the experimental data, it is clear that the stochastic trajectory of a Janus microsphere is the superposition of a random motion and a directional motion, and the particle undergoes abnormal diffusion. Then, the current complex motion is deemed as the combined action of Brownian motion, selfpropulsion and random rotation. The characteristic time scales, within which different dynamic factors are dominating, are obtained, and the model presents a reasonable explanation about the observed phenomena.
- Janus microsphere /
- selfpropulsion /
- Brownian motion /
- Hurst index /
- fractal

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