(120k) Self-Assembly of Lobed Patchy Particles | AIChE

(120k) Self-Assembly of Lobed Patchy Particles


Paul, S. - Presenter, University of New Hampshire
Vashisth, H., University of New Hampshire
Self-assembly of colloidal patchy particles is an emerging approach to fabricate different morphological structures for technological and biomedical applications. The number of patches at specific locations can cause directional anisotropic interactions to generate a targeted structure through bottom-up self-assembly. We studied self-assembly behavior of lobed patchy particles where attractive patches around a central spherical seed appear as protrusions or lobes. Lobes around a central repulsive seed, instead of surface patches, are more likely to produce higher excluded volume in their assembled structures due to directional interactions, thereby generating porous structures. We studied seven different lobed particles: snowman, dumbbell, trigonal planar, square planar, tetrahedral, trigonal bipyramid and octahedral. We tuned the inter-lobe interactions and showed that novel amorphous and crystalline structures can be obtained from lobed particles. For example, dumbbell shaped particles were observed to self-assemble into rings, trigonal planar particles self-assemble into cylindrical tubes and square planar particles assemble into crystalline cuboctahedron. We investigated the pore diameters and found that dumbbell shaped particles contain the biggest pores in their assembled structures due to the formation of 5, 6 or 7 membered rings. We further examined the effect of lobe size on the self-assembled morphologies formed at a range of temperatures. Depending on the lobe size, most particles were found to undergo a transition from random aggregates to liquid droplets or from the crystalline structures to liquid droplets with the increase in temperature.