Dynamic charge separation in a liquid crystalline meniscus

Ionic polarization of liquid-liquid interfaces; dynamic control of the rate of electro-coalescence

“…2(b)). Our results are consistent with the dynamic charge separation mechanism (dyCHASE) that we identified earlier for freely suspended liquid crystalline film 17 and a polymer/liquid crystal blend. 18 Frequency of oscillating EF can be used to control the magnitude of electrostatic interactions in a wide class of softmatter systems.…”

Thousand‐Fold Acceleration of Phase Decomposition in Polymer/Liquid Crystal Blends

“…We define t x as the time at which q max A C H T U N G T R E N N U N G (t=t x ) = 2 mm À1 . We find that for an EF of 3.3 V mm À1 and for q max A C H T U N G T R E N N U N G (t=t x ) = 2 mm À1 , t x increases abruptly [8] suggest that this critical value of the frequency should be inversely proportional to the value of the EF. Application of a low-frequency OEF changes the evolution of L(t) qualitatively as well-from an algebraic to an exponential growth law L(t)~exp(bt).…”

“…It would be interesting to test the dependence of the threshold frequency (f CR ) on the magnitude of the EF. Our recent work [8] suggest that this critical value of the frequency should be inversely proportional to the value of the EF.…”

“…Tsori and Leibler followed up [7] with a result that ions can also influence the phase separation process in binary mixtures through a mechanism based on 1) a contrast of conductivity, due to a difference in chemical potential of ions, in each of the two phases and 2) on motion of the interface as a result of the electrophoretic force acting on the ions. We have recently shown [8] that a low-frequency oscillating EF (OEF) can induce a dynamic charge separation (dyCHASE) even over macroscopic distances (mm) in a LC meniscus.Herein we demonstrate experimentally that OEFs can be used to 1) accelerate the rate of phase separation by up to three orders of magnitude, and 2) change the character of the phase separation process from a power to an exponential evolution of the mean size of the domains.We studied the phase-separation process in the binary mixture of 5CB/PS (4-cyano-4'-n-pentyl-biphenyl/polystyrene) and 8CB/PS (4-cyano-4'-n-octyl-biphenyl/polystyrene). [9] In order to track the phase-separation process, we first annealed the samples at T > 60 8C (5CB) and T > 65 8C (8CB).…”

“…Tsori and Leibler followed up [7] with a result that ions can also influence the phase separation process in binary mixtures through a mechanism based on 1) a contrast of conductivity, due to a difference in chemical potential of ions, in each of the two phases and 2) on motion of the interface as a result of the electrophoretic force acting on the ions. We have recently shown [8] that a low-frequency oscillating EF (OEF) can induce a dynamic charge separation (dyCHASE) even over macroscopic distances (mm) in a LC meniscus.…”