Self-assembly of patchy colloidal dumbbells.
We employ Monte Carlo simulations to investigate the self-assembly of patchy colloidal dumbbells interacting via a modified Kern-Frenkel potential by probing the system concentration and dumbbell shape. We consider dumbbells consisting of one attractive sphere with diameter σ1 and one repulsive sphere with diameter σ2 and center-to-center distance d between the spheres. For three different size ratios, we study the self-assembled structures for different separations l = 2d/(σ1 + σ2) between the two spheres. In particular, we focus on structures that can be assembled from the homogeneous fluid, as these might be of interest in experiments. We use cluster order parameters to classify the shape of the formed structures. When the size of the spheres is almost equal, q = σ2/σ1 = 1.035, we find that, upon increasing l, spherical micelles are transformed to elongated micelles and finally to vesicles and bilayers. For size ratio q = 1.25, we observe a continuously tunable transition from spherical to elongated micelles upon increasing the sphere separation. For size ratio q = 0.95, we find bilayers and vesicles, plus faceted polyhedra and liquid droplets. Our results identify key parameters to create colloidal vesicles with attractive dumbbells in experiments.
Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands.
Guido
G
Avvisati
SUPA, School of Physics and Astronomy, The University of Edinburgh, Kings Buildings, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom.
Teun
T
Vissers
Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands.
Marjolein
M
Dijkstra