Phase transitions and surface properties in active colloidal solids

Professor Wang, Yufeng   (Co-Investigator (Co-I) (for projects led by other university))

Professor Wang Yufeng   (Co-principal investigator)

36

2025-03-01

660000

Phase transitions and surface properties in active colloidal solids

colloidal crystals, colloidal glasses, nonequilibrium transition tunable colloidal particles

PhysicsMaterials Sciences

Physical Sciences (P)

C6041-24G

Collaborative Research Fund (CRF) - Group Research Project 2024/2025

2024

On-going

1. Semi-active glasses. To fabricate various types of tunable colloidal glasses composed of active and passive micro-spheres, including 2D and 3D glasses, ultrastable glasses, ordinary glasses, and ""less-stable"" glasses. These types of glasses have been fabricated before using passive colloids, but not using passive–active mixtures. The properties of the glasses, particularly the effects of activity, will be studied. The liquid-to- glass transition, glass melting, and surface properties of the glasses will be studied using colloidal model systems. These properties have been studied before in passive colloidal systems through volume fraction adjustment, but not in passive–active mixtures or through activity tuning.2. Semi-active crystals. To fabricate tunable colloidal crystals composed of active and passive microspheres and crystals with size-controllable active/passive domains. The activity-induced defect generation, motion, and surface and bulk melting of the crystals will be studied. We will attempt to achieve crystallization by reducing the activity. We will also test a few theoretical predictions, such as the effect of non-communitive hydrodynamic force in active crystals.3. Semi-active gels. To add active colloids to soft gels and examine how they affect gelation or percolation transitions. We will characterize the effect of activity on the macroscopic mechanical properties and surface behaviors, and the mechanisms through which colloidal density, activity, and gel viscoelasticity control the autonomous elastic modes.4. To fabricate new types of anisotropic active and passive colloidal particles and explore novel phase transitions. We will fabricate active and passive micro-platelets with custom-designed shapes and assemble them into liquid crystal phases and chiral phases.