Adsorbed films of three-patch colloids: Continuous and discontinuous transitions between thick and thin films

摘要

We investigate numerically the role of spatial arrangement of the patches onthe irreversible adsorption of patchy colloids on a substrate. We considerspherical three-patch colloids and study the dependence of the kinetics on theopening angle between patches. We show that growth is suppressed below andabove minimum and maximum opening angles, revealing two absorbing phasetransitions between thick and thin film regimes. While the transition at theminimum angle is continuous, in the Directed Percolation class, that at themaximum angle is clearly discontinuous. For intermediate values of the openingangle, a rough colloidal network in the Kardar-Parisi-Zhang universality classgrows indefinitely. The nature of the transitions was analyzed in detail byconsidering bond flexibility, defined as the dispersion of the angle betweenthe bond and the center of the patch. For the range of flexibilities consideredwe always observe two phase transitions. However, the range of opening angleswhere growth is sustained increases with flexibility. At a tricriticalflexibility, the discontinuous transition becomes continuous. The practicalimplications of our findings and the relation to other nonequilibriumtransitions are discussed.