实践十号卫星开展空间固液界面胶体自组装动力学行为研究

微流动驱动的胶体自组装是一种非平衡的过程。在定向微流动(如热毛细流)驱动下，胶体体系内的粒子自身的热运动受到抑制，胶体体系中的微粒常常出现宏观有序的结构。但这种粒径的球在重力作用下会显著沉降，造成胶体体系的浓度不均，而胶体体系的相行为与浓度密切相关。因此在重力作用下难以准确地描述相变与局域结构的关联。在微重力条件下，大尺度的胶体球没有重力沉降作用，可提供准确的局域结构信息，而且浮力对流受到较大抑制，没有流体静压力，不产生沉降作用，这为研究界面上的胶体自组装动力学行为提供了有利条件。“胶体有序排列及新型材料研究”是“实践十号卫星”19项科学实验载荷之一，其科学实验将在载荷“胶体材料箱”中完成，将是空间中进行的首次胶体自组装动力学行为的实验研究。

Study the dynamic behavior of the colloidal particles self-assembling at the solid-liquid interface on the SJ-10 satellite

The colloidal self-assembly driven by micro-flow an un-equilibrium process. The thermal motion of the colloidal particles in the colloidal system is suppressed due to the directional micro-flow that often lead to the macroscopic ordered structure. However, the particles significantly sedimentation under gravity, resulting in uneven concentration of the colloidal system, and phase behavior of colloidal systems is closely related to the concentration. Therefore, it is difficult to describe the correlation between the phase transition and the local structure accurately under the gravity. The sedimentation of the colloidal particles will disappear under the microgravity, and the system can provide accurate local structural information. In microgravity, the buoyancy convection was suppressed seriously, and there is no hydrostatic pressure, no sedimentation, which provided favorable conditions for in-situ observation of the colloidal self-assembly.