# gst: anisotropic active depletion around a self-propelled non-interactive colloids; three characteristic states could be identified.

<< Active colloids in a bath of inert particles of smaller size cause anisotropic depletion. >>️

Here AA << combine mesoscale hydrodynamic simulation as well as theoretical analysis to examine the physical origin for the active depletion around a self-propelled noninteractive colloid. >>️

Their << results elucidate that the variable hydrodynamic effect critically governs the microstructure of the depletion zone. Three characteristic states of anisotropic depletion are identified, depending on the strength and stress of activity. >>️

<< Furthermore, (AA) demonstrate that such depletion in nonequilibrium results in various clusters with ordered organization of squirmers, which follows a distinct principle contrary to that of the entropy scenario of depletion in equilibrium. >>

️

Lijun Dai, Haixiao Wan, et al. Hydrodynamic Anisotropy of Depletion in Nonequilibrium. Phys. Rev. Lett. 131, 134002. Sep 27, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.134002

Also: particle, colloids, in https://www.inkgmr.net/kwrds.html

Keywords: gst, particles, colloids, depletion, squirmers, self-propulsion systems

# gst: soft and stiff modes in colloidal particle networks

<< Floppy microscale spring networks are widely studied in theory and simulations, but no well-controlled experimental system currently exists. >> 

AA << show that square lattices consisting of colloid-supported lipid bilayers functionalized with DNA linkers act as microscale floppy spring networks. (AA) extract their normal modes by inverting the particle displacement correlation matrix, showing the emergence of a spectrum of soft modes with low effective stiffness in addition to stiff modes that derive from linker interactions. >>

<< Evaluation of the softest mode, a uniform shear mode, reveals that shear stiffness decreases with lattice size. >>

 AA << results reveal the importance of entropic steric effects. >>

️

Julio Melio, Silke E. Henkes, Daniela J. Kraft. Soft and Stiff Normal Modes in Floppy Colloidal Square Lattices. Phys. Rev. Lett. 132, 078202. Feb 14, 2024. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.078202

Also: particle, nano, colloids, network, in https://www.inkgmr.net/kwrds.html

Keywords: gst, particle, nano, colloids, network, colloidal network

# gst: stochastic resonance mediated by optimal noise level values; transport of colloidal particles induced by substrate concentration oscillations.

AA << show the existence of a  stochastic resonant regime in the transport of active colloidal particles under confinement. The periodic addition of substrate to the system causes the spectral amplification to exhibit a maximum for an optimal noise level value. The consequence of this is that particles can travel longer distances with lower fuel consumption. The stochastic resonance phenomenon found allows the identification of optimal scenarios for the transport of active particles, enabling them to reach regions that are otherwise difficult to access, and may therefore find applications in transport. >>️

J. D. Torrenegra-Rico, A. Arango-Restrepo, J. M. Rubi. Optimal transport of active particles induced by substrate concentration oscillations. Phys. Rev. E 108, 014134. July 28, 2023.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.108.014134

Img: https://twitter.com/PhysRevE/status/1687119409096089602

Also: particle, colloids, noise, in:  https://www.inkgmr.net/kwrds.html

Keywords: gst, particle, colloids, noise, stochastic resonance, substrate oscillation

# gst: ️apropos of spontaneous active matter, the active droploids.

<< Active matter comprises self-driven units, such as bacteria and synthetic microswimmers, that can spontaneously form complex patterns and assemble into functional microdevices. These processes are possible thanks to the out-of-equilibrium nature of active-matter systems, fueled by a one-way free-energy flow from the environment into the system. Here, (AA) take the next step in the evolution of active matter by realizing a two-way coupling between active particles and their environment, where active particles act back on the environment giving rise to the formation of superstructures. >>️

<< These structures hinge on mutually coupled structure formation processes of the colloids, which form an engine, and the surrounding solvent, which phase separates in regions of high colloidal density and encapsulates the engine within a droplet shell.  >>

️

Jens Grauer, Falko Schmidt, et al. Active droploids. arXiv:2109.10677v1 [cond-mat.soft]. Sep 22, 2021.

https://arxiv.org/abs/2109.10677

Also

keyword 'drop' | 'droplet' in FonT

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

keyword 'goccia' in Notes (quasi-stochastic poetry): 

https://inkpi.blogspot.com/search?q=goccia

keywords: gst, drops, droplets, colloids, active matter, active droploids, self-assembly, solitons.

# rmx-s-chem-nano: digital alchemy, a new frontier ...

<< Alchemy left the mainstream centuries ago, but one of its core concepts, transmuting the elements, is experiencing a revival in nanotechnology >>

http://www.nanowerk.com/nanotechnology-news/newsid=41725.php

<< (..) how to exploit the malleability of the valence of colloidal nanoparticle “elements” to directly and quantitatively link building-block attributes to bulk structure through a statistical thermodynamic framework we term “digital alchemy” >>

Greg van Anders, Daphne Klotsa et al., Digital Alchemy for Materials Design: Colloids and Beyond. ACS Nano, 2015, 9 (10), pp 9542–9553. DOI: 10.1021/acsnano.5b04181

http://pubs.acs.org/doi/10.1021/acsnano.5b04181

# gst: emergence of self-organizing zigzag patterns among (magnetic) particles suspended in a liquid

<< When molecules or bacteria organize into a long-range pattern, researchers want to understand how the microscopic interactions lead to the macroscopic order. (AA) observed such self-organization in magnetic particles suspended in a liquid and subjected to an oscillating magnetic field. Through experiments and simulations, the team showed that the resulting zigzag pattern is explained by the fluid flow generated around the oscillating particles, not by any details of the particles or the applied field. Similar zigzag patterns have also been seen in charged colloids subjected to oscillating electric fields, so the explanation may cover a range of particle systems. The researchers also believe that understanding and controlling the effect could lead to useful applications in microfluidics devices. >>️

David Ehrenstein. Self-Organized Zigzags from Fluid Flow. Physics 16, 138. Aug 11, 2023.

https://physics.aps.org/articles/v16/138

Gaspard Junot, Marco De Corato, Pietro Tierno. Large Scale Zigzag Pattern Emerging from Circulating Active Shakers. Phys. Rev. Lett. 131, 068301. Aug 11, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.068301

Also: particle, self-assembly, chiral, behav, in: https://www.inkgmr.net/kwrds.html  

Keywords: gst, behavior, particle, self-assembly, self-organization, chiral, active shakers, squirmers, alternating chirality

# gst: like the slender body theory, the effect of curvature on the diffusion of colloidal bananas.

<< Anisotropic colloidal particles exhibit complex dynamics which play a crucial role in their functionality, transport, and phase behavior.  >>️

AA << investigate the two-dimensional diffusion of smoothly curved colloidal rods—also known as colloidal bananas—as a function of their opening angle α >>️

<< the experimental results are consistent with slender body theory, indicating that the dynamical behavior of the particles arises primarily from their local drag anisotropy. These results highlight the impact of curvature on the Brownian motion of elongated colloidal particles, which must be taken into account when seeking to understand the behavior of curved colloidal particles. >>️

Justin-Aurel Ulbrich, Carla Fernández-Rico, et al. Effect of curvature on the diffusion of colloidal bananas. Phys. Rev. E 107, L042602. April 21, 2023.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.107.L042602

Img: https://twitter.com/PhysRevE/status/1650782974722338816

Also: gst, particle, in https://www.inkgmr.net/kwrds.html

Keywords: gst, colloids, particles, behavior

# gst: critical points seem to act behind the complex behavior of collectives.

<< Current experiments support the controversial hypothesis that a well-known concept in physics—a critical point—is behind the striking behavior of collective animal systems. >>

AA << showed that light-controlled microswimming particles can be made to organize into collective states such as swarms and swirls. By studying the particles fluctuating between these states, they provide evidence for critical behavior—and support for a physical principle underlying the complex behavior of collectives.>>

<< What we observed is that the system can make sudden transitions from one state to the other, which demonstrates the flexibility needed to react to an external perturbation like a predator, (..) and provides clear evidence for a critical behavior. >> Clemens Bechinger

<< Through very simple interactions, they have shown that you can tune a physical system to a collective state - criticality - of balance between order and disorder. >> Iain Couzin

Physics principle explains order and disorder of swarms. University of Konstanz. Jun 11, 2020.

https://phys.org/news/2020-06-physics-principle-disorder-swarms.html

Bauerle T., Loffler R.C., Bechinger C. Formation of stable and responsive collective states in suspensions of active colloids. Nat Commun 11, 2547. doi: 10.1038/ s41467-020-16161-4. May 21, 2020.

https://www.nature.com/articles/s41467-020-16161-4

Also 

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

# chem: spontaneous reconfiguration of deformable nanoparticles (in response to environmental cues)

<< Deformable nanoparticles (NPs) offer unprecedented opportunities as dynamic building blocks that can spontaneously reconfigure during assembly in response to environmental cues. >>

<< deformable spherical NPs of radius 50 nm whose surface is tailored with octahedrally distributed charged patches and double-cap charged patches adapt their shape differently in response to changes in surface charge coverage and ionic strength. >>

AA << find shape transitions to rounded octahedra, faceted octahedra, faceted bowls, oblate spheroids, spherocylinders, dented beans, and dimpled rounded bowls. >>

AA << demonstrate that similar shape transitions can be achieved in deformable NPs of different sizes. >>️

Fanbo Sun, Nicholas E. Brunk, Vikram Jadhao. Shape control of deformable charge-patterned nanoparticles. Phys. Rev. E 107, 014502. Jan 10, 2023.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.107.014502

Img https://twitter.com/PhysRevE/status/1613183219377086468

Also

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

keyword 'nano' in FonT

https://flashontrack.blogspot.com/search?q=nano

keyword 'nano' in Notes 

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=nano

Keywords: chem, nano, nanoparticles,  NPs, self-assembly, colloids, polymers, vesicle structures.