Motion of a Janus particle very near a wall.
Motion of a Janus particle very near a wall.
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DOI：
10.1063/1.4994843
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发表时间：
2017-12
期刊：
影响因子：
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通讯作者：
Aidin Rashidi;C. Wirth
中科院分区：
文献类型：
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作者：
Aidin Rashidi;C. Wirth
这篇文章描述了一个球体的模拟布朗运动，该球体包括具有不等zeta电位的半球（即，“Janus”粒子）非常靠近墙壁。模拟工具的开发和使用，以协助在方法的发展应用全内反射显微镜（TIRM）各向异性颗粒。模拟的Janus球的轨迹与帽密度匹配的基础粒子非常接近边界被用来构建三维势能景观，随后用于推断粒子和溶液的属性，将在TIRM测量。结果表明，Janus球的势能分布在两个Janus球的边界处存在一个过渡区，该过渡区的大小取决于相对zeta电位的大小。势能景观被拟合以准确地获得每个半球的zeta电位、颗粒尺寸、最小势能位置和电解质浓度或德拜长度。我们还确定了适当的取向箱的大小和制度的势能景观应适合获得系统的属性。我们的模拟表明，实验可能需要超过106个观测值才能获得合适的势能景观，这是各向异性粒子观测的多变量性质的结果。这些结果说明了进行TIRM各向异性颗粒的重要考虑。
This article describes the simulated Brownian motion of a sphere comprising hemispheres of unequal zeta potential (i.e., "Janus" particle) very near a wall. The simulation tool was developed and used to assist in the methodology development for applying Total Internal Reflection Microscopy (TIRM) to anisotropic particles. Simulations of the trajectory of a Janus sphere with cap density matching that of the base particle very near a boundary were used to construct 3D potential energy landscapes that were subsequently used to infer particle and solution properties, as would be done in a TIRM measurement. Results showed that the potential energy landscape of a Janus sphere has a transition region at the location of the boundary between the two Janus halves, which depended on the relative zeta potential magnitude. The potential energy landscape was fit to accurately obtain the zeta potential of each hemisphere, particle size, minimum potential energy position and electrolyte concentration, or Debye length. We also determined the appropriate orientation bin size and regimes over which the potential energy landscape should be fit to obtain system properties. Our simulations showed that an experiment may require more than 106 observations to obtain a suitable potential energy landscape as a consequence of the multivariable nature of observations for an anisotropic particle. These results illustrate important considerations for conducting TIRM for anisotropic particles.