Self-assembly of “Mickey Mouse” shaped colloids into tube-like structures: experiments and simulations

Abstract

The self-assembly of anisotropic patchy particles with a triangular shape was studied by experiments and computer simulations. The colloidal particles were synthesized in a two-step seeded emulsion polymerization process, and consist of a central smooth lobe connected to two rough lobes at an angle of $90, resembling the shape of a "Mickey Mouse" head. Due to the difference in overlap volume, adding an appropriate depletant induces an attractive interaction between the smooth lobes of the colloids only, while the two rough lobes act as steric constraints. The essentially planar geometry of the Mickey Mouse particles is a first geometric deviation of dumbbell shaped patchy particles. This new geometry enables the formation of one-dimensional tube-like structures rather than spherical, essentially zero-dimensional micelles. At sufficiently strong attractions, we indeed find tube-like structures with the sticky lobes at the core and the non-sticky lobes pointing out as steric constraints that limit the growth to one direction, providing the tubes with a well-defined diameter but variable length both in experiments and simulations. In the simulations, we found that the internal structure of the tubular fragments could either be straight or twisted into so-called Bernal spirals.

Self-assembly of trimer colloids: effect of shape and interaction range

“…14,15 Trimers of a single shape were experimentally synthesized and observed to form elongated structures. 15 These trimers were also studied computationally in order to analyze the self-assembled structures and compare with experiment.…”

“…14,15 Trimers of a single shape were experimentally synthesized and observed to form elongated structures. 15 These trimers were also studied computationally in order to analyze the self-assembled structures and compare with experiment. 15 Other previous simulation studies include trimers with different number of attractive beads, 16,17 dimers, 14,18–21 and tetramers.…”

Limiting the valence: advancements and new perspectives on patchy colloids, soft functionalized nanoparticles and biomolecules

“…162 When focusing on one-component systems of anisotropic particles decorated with anisotropic bonding patterns, most of the results accumulated so far in the literature deal with Janus-like nonspherical entities -mainly elongated shapes carrying one or at most two patches -assembling into a vast variety of fiber-like structures with diverse applications. Janus nano-cylinders that form vertical, horizontal or even smectic arrays, 163,164 ellipsoids with one patch in a Janus-like or ''kayak'' fashion that form ordered assemblies 165 or even field-sensitive colloidal fibers, 166 ''Mickey Mouse''-shaped colloidal molecules that form tubular aggregates, 167 and silica rods coated with gold tips that self-assemble into different multipods 168 are just a few examples. The susceptibility of Janus-like anisotropic units to external fields can also be used to drive the assembly into string-like structures.…”

Supercharging enables organized assembly of synthetic biomolecules

“…Given that both natural proteins 3-8 and synthetic colloids [18][19][20][21][22][23][24][25][26][27][28][29] have been shown to readily assemble into symmetric, higher order structures, we anticipate that our SuPrA strategy can now be generalized to create synthetic, scalable…”

“…Notably, while some GFP variants, including the parent protein originally found in Aeqorea Victoria dimerize, the native dimer structure fits poorly into the electron density maps of the protomer, suggesting that the architecture of the protomer is completely novel. 54 The formation of SuPrA protomers appears to be largely independent of the placement of charges, suggesting that oppositely supercharging protein variants may generally drive formation into 'stacked' or brick-like structures whose overall form is determined by symmetric interactions.Given that both natural proteins 3-8 and synthetic colloids [18][19][20][21][22][23][24][25][26][27][28][29] have been shown to readily assemble into symmetric, higher order structures, we anticipate that our SuPrA strategy can now be generalized to create synthetic, scalableAll rights reserved. No reuse allowed without permission.…”