Stochastic buckling of self-assembled colloidal structures

Abstract

Although buckling is a prime route to achieve functionalization and synthesis of single colloids, buckling of colloidal structures-made up of multiple colloids-remains poorly studied. Here, we investigate the buckling of the simplest form of a colloidal structure, a colloidal chain that is selfassembled through critical Casimir forces. We demonstrate that the mechanical instability of such a chain is strikingly reminiscent of that of classical Euler buckling but with thermal fluctuations and plastic effects playing a significant role. Namely, we find that fluctuations tend to diverge close to the onset of buckling and that plasticity controls the buckling dynamics at large deformations. Our work provides insight into the effect of geometrical, thermal and plastic interactions on the nonlinear mechanics of self-assembled structures, of relevance for the rheology of complex and living matter and the rational design of colloidal architectures.

Thermal buckling and symmetry breaking in thin ribbons under compression

“…The second approach is via height fluctuations (Appendix B), in analogy with the study of susceptibility in magnetic systems. Such an increase in height fluctuations close to the buckling transition was recently observed in the study of buckling of 1D colloidal systems [41]. Lastly, we find that the height becomes highly sensitive to an out-of-plane symmetry-breaking field E close to the transition.…”

Extreme mechanics of colloidal polymers under compression: Buckling, creep, and break-up

“…This agreement with the Euler model further indicates that for moderate strains, the response of the chain is predominantly elastic, and viscous contributions are minimal. Compared to simple linear aggregates of isotropic particles that also exhibit buckling behavior [35], the behavior observed here is in even much better agreement with continuum theory. This is likely due to the more perfect straightness of the chain afforded by the dipatch particle geometry.…”

“…Averaging over all the measurements yields θ * b = 0.20(5) rad, consistent within accuracy with the patch arc angle. From this correspondence we conclude that the breaking transition arises from the limited patch size, which explains the striking difference with the response of isotropic particle chains [35].…”

Chromatographic separation of active polymer–like worm mixtures by contour length and activity

“…So far, this research has focused mostly on point-like particles (18)(19)(20)(21)(22)(23)(24), and much less is known about active polymers (25). The term "active polymers" has been used to describe a wide variety of systems, including synthetic colloidal systems that can be assembled and pushed out of equilibrium (26,27) and dynamic self-assembling polymers and filaments encountered in biological systems (28). Here, we will use the term "active polymer" to refer to a chain-like structure of which the segments exhibit active motion.…”