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Self-assembled wiggling nano-structures and the principle of maximum entropy production.

Belkin A, Hubler A, Bezryadin A - Sci Rep (2015)

Bottom Line: Curiously, we find that emerging self-assembled structures can start to wiggle.The wiggling takes place only until the entropy production in the suspension reaches its maximum, at which time the wiggling stops and the structure becomes quasi-stable.Thus, we provide strong evidence that maximum entropy production principle plays an essential role in the evolution of self-organizing systems far from equilibrium.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL.

ABSTRACT
While behavior of equilibrium systems is well understood, evolution of nonequilibrium ones is much less clear. Yet, many researches have suggested that the principle of the maximum entropy production is of key importance in complex systems away from equilibrium. Here, we present a quantitative study of large ensembles of carbon nanotubes suspended in a non-conducting non-polar fluid subject to a strong electric field. Being driven out of equilibrium, the suspension spontaneously organizes into an electrically conducting state under a wide range of parameters. Such self-assembly allows the Joule heating and, therefore, the entropy production in the fluid, to be maximized. Curiously, we find that emerging self-assembled structures can start to wiggle. The wiggling takes place only until the entropy production in the suspension reaches its maximum, at which time the wiggling stops and the structure becomes quasi-stable. Thus, we provide strong evidence that maximum entropy production principle plays an essential role in the evolution of self-organizing systems far from equilibrium.

No MeSH data available.


Related in: MedlinePlus

Motion of the CNT “bug” under the influence of dc electric field.Panel (a) illustrates positions of the “arms” of the bug when they are retracted (t = T), approaching (t = T+2 s), touching (t = T+3 s) and again retracted (t = T+9 s) from the right electrode. Here T~2500 s. The movie showing the motion of the selfassembled wiggling structure is contained in Supplementary Information online. Panel (b) demonstrates the time dependence of the normalized power dissipated by the bug. Inset: a segment of the time dependence of the normalized power, corresponding to the phase when the bug is fully developed and exhibits the arm motion. At t~4500 s the stable phase begins.
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f5: Motion of the CNT “bug” under the influence of dc electric field.Panel (a) illustrates positions of the “arms” of the bug when they are retracted (t = T), approaching (t = T+2 s), touching (t = T+3 s) and again retracted (t = T+9 s) from the right electrode. Here T~2500 s. The movie showing the motion of the selfassembled wiggling structure is contained in Supplementary Information online. Panel (b) demonstrates the time dependence of the normalized power dissipated by the bug. Inset: a segment of the time dependence of the normalized power, corresponding to the phase when the bug is fully developed and exhibits the arm motion. At t~4500 s the stable phase begins.

Mentions: Occasionally, towards the end of the avalanche phase, nanotubes form a dissipative pattern that exhibits quasi-periodic collective motion and deformation. Figure 5 shows an example of such a dissipative structure (CNT bug) that self-assembled around one of the electrodes (see video in Supplementary Information). A few chains of nanotubes form thick CNT “arms” that protrude out of this bug and extend towards the opposite electrode (Fig. 5a, 2s). Their motion forces the cloud to displace, causing its slight deformation. When the arms touch the electrode, they remain in contact with it for a short period of time (Fig. 5a, 3s), and then retract (Fig. 5a, 9s). Subsequently, the process repeats again (Fig. 5a). This wiggling of the dissipative structure is surprising since the applied voltage is constant in time. The extension and retraction of several CNT arms is almost synchronous. The motion of the CNT bug is repeated and can be characterized as quasi-periodic, up until the stabilization transition when the system enters the stable evolution phase.


Self-assembled wiggling nano-structures and the principle of maximum entropy production.

Belkin A, Hubler A, Bezryadin A - Sci Rep (2015)

Motion of the CNT “bug” under the influence of dc electric field.Panel (a) illustrates positions of the “arms” of the bug when they are retracted (t = T), approaching (t = T+2 s), touching (t = T+3 s) and again retracted (t = T+9 s) from the right electrode. Here T~2500 s. The movie showing the motion of the selfassembled wiggling structure is contained in Supplementary Information online. Panel (b) demonstrates the time dependence of the normalized power dissipated by the bug. Inset: a segment of the time dependence of the normalized power, corresponding to the phase when the bug is fully developed and exhibits the arm motion. At t~4500 s the stable phase begins.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321171&req=5

f5: Motion of the CNT “bug” under the influence of dc electric field.Panel (a) illustrates positions of the “arms” of the bug when they are retracted (t = T), approaching (t = T+2 s), touching (t = T+3 s) and again retracted (t = T+9 s) from the right electrode. Here T~2500 s. The movie showing the motion of the selfassembled wiggling structure is contained in Supplementary Information online. Panel (b) demonstrates the time dependence of the normalized power dissipated by the bug. Inset: a segment of the time dependence of the normalized power, corresponding to the phase when the bug is fully developed and exhibits the arm motion. At t~4500 s the stable phase begins.
Mentions: Occasionally, towards the end of the avalanche phase, nanotubes form a dissipative pattern that exhibits quasi-periodic collective motion and deformation. Figure 5 shows an example of such a dissipative structure (CNT bug) that self-assembled around one of the electrodes (see video in Supplementary Information). A few chains of nanotubes form thick CNT “arms” that protrude out of this bug and extend towards the opposite electrode (Fig. 5a, 2s). Their motion forces the cloud to displace, causing its slight deformation. When the arms touch the electrode, they remain in contact with it for a short period of time (Fig. 5a, 3s), and then retract (Fig. 5a, 9s). Subsequently, the process repeats again (Fig. 5a). This wiggling of the dissipative structure is surprising since the applied voltage is constant in time. The extension and retraction of several CNT arms is almost synchronous. The motion of the CNT bug is repeated and can be characterized as quasi-periodic, up until the stabilization transition when the system enters the stable evolution phase.

Bottom Line: Curiously, we find that emerging self-assembled structures can start to wiggle.The wiggling takes place only until the entropy production in the suspension reaches its maximum, at which time the wiggling stops and the structure becomes quasi-stable.Thus, we provide strong evidence that maximum entropy production principle plays an essential role in the evolution of self-organizing systems far from equilibrium.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL.

ABSTRACT
While behavior of equilibrium systems is well understood, evolution of nonequilibrium ones is much less clear. Yet, many researches have suggested that the principle of the maximum entropy production is of key importance in complex systems away from equilibrium. Here, we present a quantitative study of large ensembles of carbon nanotubes suspended in a non-conducting non-polar fluid subject to a strong electric field. Being driven out of equilibrium, the suspension spontaneously organizes into an electrically conducting state under a wide range of parameters. Such self-assembly allows the Joule heating and, therefore, the entropy production in the fluid, to be maximized. Curiously, we find that emerging self-assembled structures can start to wiggle. The wiggling takes place only until the entropy production in the suspension reaches its maximum, at which time the wiggling stops and the structure becomes quasi-stable. Thus, we provide strong evidence that maximum entropy production principle plays an essential role in the evolution of self-organizing systems far from equilibrium.

No MeSH data available.


Related in: MedlinePlus