A qualitative confocal microscopy study on a range of colloidal processes by simulating microgravity conditions through slow rotations

摘要: We report qualitatively on the differences between colloidal systems left to evolve in Earth’s gravitational field and same for which a slow continuous rotation averaged out effects of particle sedimentation distance scale small compared size. Several micron-sized particles were studied: hard sphere fluid, colloids interacting via long-range electrostatic repulsion above freezing volume fraction, an oppositely charged system close either gelation and/or crystallization, with competing short-range depletion attraction repulsion, dipolar chains, gold platelets under conditions where they formed stacks. Important structure formation observed experiments allowed sediment those was out. For instance, case unusual sequence dilute-fluid–dilute-crystal–dense-fluid–dense-crystal phases throughout suspension effect gravity. This related fraction dependence interactions, whereas stayed homogeneously crystallized rotation. colloids, gel-like found collapse influence gravity few crystalline layers grown top sediment, when out, gel completely transformed into crystallites that oriented randomly sample. Rotational averaging is effective cheap way estimate importance self-assembly processes.