Abacousnac Jatin, Brujic Jasna, Grier David G
Department of Physics and Center for Soft Matter Research, <a href="https://ror.org/0190ak572">New York University</a>, New York, New York 10003, USA.
Phys Rev E. 2024 Jul;110(1-1):014605. doi: 10.1103/PhysRevE.110.014605.
In-line holographic video microscopy records a wealth of information about the microscopic structure and dynamics of colloidal materials. Powerful analytical techniques are available to retrieve that information when the colloidal particles are well separated. Large assemblies of close-packed particles create holograms that are substantially more challenging to interpret. We demonstrate that Rayleigh-Sommerfeld back propagation is useful for analyzing holograms of colloidomer chains, close-packed linear assemblies of micrometer-scale emulsion droplets. Colloidomers are fully flexible chains and undergo three-dimensional configurational changes under the combined influence of random thermal forces and hydrodynamic forces. We demonstrate the ability of holographic reconstruction to track these changes as colloidomers sediment through water in a horizontal slit pore. Comparing holographically measured configurational trajectories with predictions of hydrodynamic models both validates the analytical technique for this valuable class of self-organizing materials and also provides insights into the influence of geometric confinement on colloidomer hydrodynamics.
在线全息视频显微镜记录了有关胶体材料微观结构和动力学的大量信息。当胶体颗粒充分分离时，有强大的分析技术可用于检索该信息。紧密堆积颗粒的大型组件产生的全息图在解释上更具挑战性。我们证明瑞利 - 索末菲反向传播对于分析胶体聚合物链（微米级乳液滴的紧密堆积线性组件）的全息图很有用。胶体聚合物是完全柔性的链，在随机热力和流体动力的共同影响下会发生三维构型变化。我们展示了全息重建跟踪这些变化的能力，即胶体聚合物在水平狭缝孔中通过水沉降时的变化。将全息测量的构型轨迹与流体动力学模型的预测进行比较，既验证了针对这类有价值的自组织材料的分析技术，也深入了解了几何限制对胶体聚合物流体动力学的影响。
