Nondeterministic Wetting of Janus Microspheres at the Oil/Water Interface

We investigate the nondeterministic wetting behaviors of Janus particles at the n-decane/water interface. Upon adsorption at the interface, only some particles reach their thermodynamically stable configuration, while many remain in random nonequilibrium states likely due to contact line pinning. Experimental data and Monte Carlo simulations show that particles in nonequilibrium states with lower three-phase contact angles exhibit reduced attractive forces due to a smaller radius of the three-phase contact line. We also find that vertical translation more easily leads to equilibrium than rotational motion. This work motivates further exploration into the effects of surface tension and surface roughness on identifying the pinning energy barrier, as well as the pinning behavior of biological materials.