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@INPROCEEDINGS{Kang:1032560,
author = {Kang, Kyongok},
title = {{L}ow {I}onic {S}trength {E}quilibria and {N}on-equilibrium
{P}hase {T}ransitions of {C}harged {C}olloidal {R}ods
({DNA}-viruses)},
school = {Inha University, South Korea},
reportid = {FZJ-2024-06341},
year = {2024},
note = {This content is delivered as an invited colloquium talk.},
abstract = {At sufficiently low ionic strengths (below 1 mM Tris/HCl
buffer), long and thin, highly charged colloidal rods
(DNA-viruses) exhibit various chiral-mesophases consisting
of different orientations of chiral-nematic and helical
domains, well above the isotropic-nematic coexistence
concentration. Both non-equilibrium (in electric-field and
shear flow) [1-3] and equilibrium phase behaviour [4-7] are
presented for the concentrated suspension of charged
DNA-viruses, which is a good model system of charged
colloidal rods (DNA-rods) to predict the phase transitions;
from the nematic-to-chiral nematic and other hierarchical
chiral-mesophases (X-pattern and helical domains) to the
glass states, in an increase of the rod-concentration [4-6].
In last 2 decades, several instrumentations and methods are
also developed to characterize both signal-and
image-processing (under external fields) in access multiple
phases and various transitions, dynamics, and kinetics of
the interacting charged DNA-rods. In this talk, experiments
on both equilibrium and the field-induced phase transition,
as well shear response of the glass state will be discussed.
The (structural) glass transition occurs well within the
full chiral-nematic state, where the particle dynamics and
the orientation texture dynamics are simultaneously
arrested, at the same concentration. The glass is also found
to exhibit several types of non-uniform flow profiles,
depending on the externally applied shear rate: At low shear
rates plug flow is observed and at intermediate shear rates
gradient-banded flow profiles are found. At high shear rates
the glass is melted, leading to a linear flow profile.
Finally, as one of interesting findings for
chiral-mesophases, is a “chiral-glass”, driven by the
replica symmetry breaking (RSB), determined by both real-
and Fourier-space [6], kept between the two “replicas”
of larger chiral-nematic domain (at a lower concentration)
and the “helical-domains” (at a higher concentration) of
charged DNA-rods [7]. As will be shown, there is a subtle
interplay between the stress originating from inter-particle
interactions within the domains and the texture stress due
to inter-domain interactions.References:[1] K. Kang and
J.K.G. Dhont, “An electric-field induced dynamical state
in dispersions of highly charged colloidal rods: Comparison
of experiment and theory”, Colloid. Polym. Sci. 293,
3325-3336, 2015: Soft Matter 10, 3311 (2014). [2] K. Kang,
“Response of shear in bulk orientations of charged DNA
rods: Taylor- and Gradient-banding”, J. Phys. Commun, 5,
045011, 2021. [3] D. Parisi, D. Vlassopoulos, H. Kriegs, J.
K. G. Dhont, and K. Kang, “Underlying mechanism of
shear-banding in soft glasses of charged colloidal rods with
orientational domains”, Journal of Rheology 66, 365, 2022:
Phys. Rev. Fluids 2, 043301 (2017). [4] K. Kang and J. K. G.
Dhont, “Glass transition in suspensions of charged rods:
Structural arrest and texture dynamics”, Phys. Rev. Lett.
110, 015901, 2013: K. Kang, “Glass transition of repulsive
charged rods (fd-viruses)”, Soft Matter, 10, 3311-3324,
2014: Soft Matter 9, 4401 (2013). [5] K. Kang,
“Equilibrium phase diagram and thermal responses of
charged DNA-virus rod-suspensions at low ionic strengths”,
Sci. Rep. 11: 3472, 2021. [6] K. Kang, “Chiral glass of
charged DNA rods, Cavity loops”, J. Phys. Commun, 5,
065001, 2021. [7] K. Kang, “Characterization of
orientation correlation kinetics: chiral-mesophase domains
in suspensions charged DNA-rods”, J. Phys. Commun, 6,
015001, 2022.},
month = {Oct},
date = {2024-10-31},
organization = {(South Korea), 31 Oct 2024 - 31 Oct
2024},
subtyp = {Invited},
cin = {IBI-4},
cid = {I:(DE-Juel1)IBI-4-20200312},
pnm = {5241 - Molecular Information Processing in Cellular Systems
(POF4-524)},
pid = {G:(DE-HGF)POF4-5241},
typ = {PUB:(DE-HGF)31},
url = {https://juser.fz-juelich.de/record/1032560},
}