Ground Experimental Study of the Colloidal Material Box aboard SJ-10 Satellite

The colloidal material box is one of the important subsystems of SJ-10 satellite, which is used for studying the self-assembly of the colloidal spheres in space. The ground experiment is an important way for exploring space experimental conditions. This paper introduces the ground experiments around the colloidal material box. First of all, a hydrophobic/hydrophilic confined substrate is prepared, and rule of the apparent contact angle under evaporation is analyzed. The particle deposition behavior of the confined colloidal droplet in evaporation process is investigated by using an in-situ optical observation system, and it is found that the pattern formation process is controlled by three dynamics behaviors. The self-excited oscillation mechanism of droplets pinned on a confined substrate is also studied by drop tower and high-speed photography technology, which shows that the two stages of the oscillation process have different characteristics. The ground experimental results offer important assurance for in-orbit experiment conditions and contrast of space and ground experiments, and are meaningful for engineering parameters setting and experiment conditions matching.