This title appears in the Scientific Report :
2014
Please use the identifier:
http://dx.doi.org/10.3389/fphy.2014.00073 in citations.
Please use the identifier: http://hdl.handle.net/2128/8386 in citations.
Electric-field induced microdynamics of charged rods
Electric-field induced microdynamics of charged rods
Electric-field induced phase/state transitions are observed in AC electric fields with small amplitudes and low frequencies in suspensions of charged fibrous viruses (fd), which are model systems for highly charged rod-like colloids. Texture- and particle-dynamics in these field-induced states, and...
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Personal Name(s): | Kang, Kyongok (Corresponding Author) |
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Contributing Institute: |
Weiche Materie; ICS-3 |
Published in: | Frontiers in Physics, 2 (2014) S. 73 |
Imprint: |
Lausanne
Frontiers Media
2014
|
DOI: |
10.3389/fphy.2014.00073 |
Document Type: |
Journal Article |
Research Program: |
Soft Matter Composites |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/8386 in citations.
Electric-field induced phase/state transitions are observed in AC electric fields with small amplitudes and low frequencies in suspensions of charged fibrous viruses (fd), which are model systems for highly charged rod-like colloids. Texture- and particle-dynamics in these field-induced states, and on crossing transition lines, are explored by image time-correlation and dynamic light scattering, respectively. At relatively low frequencies, starting from a system within the isotropic-nematic coexistence region, a transition from a nematic to a chiral nematic is observed, as well as a dynamical state where nematic domains melt and reform. These transitions are preliminary due to field-induced dissociation/association of condensed ions. At higher frequencies a uniform state is formed that is stabilized by hydrodynamic interactions through field-induced electro-osmotic flow where the rods align along the field direction. There is a point in the field-amplitude vs. frequency plane where various transition lines meet. This point can be identified as a “non-equilibrium critical point,” in the sense that a length scale and a time scale diverge on approach of that point. The microscopic dynamics exhibits discontinuities on crossing transition lines that were identified independently by means of image and signal correlation spectroscopy. |