Influence of ionic transport on deformations of homeotropic nematic layers with positive flexoelectric coefficients

Buczkowska, M.; Derfel, Grzegorz

doi:10.1080/02678290500303221

Cited by 21 publications

(19 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect is cau− sed by the difference between mobilities of anions and cat− ions which leads to the non−uniform electric field distribu− tion. Average electric field strength in the vicinity of the cathode is larger than that in the neighbourhood of the anode [12][13][14]. Therefore, the bulk torque of dielectric nature which is proportional to the square of the electric field strength has different effectiveness for the two orienta− tions of the layer.…”

Section: Discussionmentioning

confidence: 99%

“…The sys− tem was described by a set of ten equations [12,13,16] con− sisting of a torque equation for the bulk, two torque equa− tions for the boundaries, an electrostatic equation, two equa− tions of continuity of anions and cations fluxes in the bulk and four equations describing the boundary conditions for ion transfers across the electrode contacts. This set of equa− tions was solved numerically.…”

Section: Methodsmentioning

confidence: 99%

“…In our previous papers, we analysed the elastic deforma− tions of symmetrical nematic layers occurring under the action of external dc electric field [12][13][14][15][16][17]. The flexoelectric properties and the presence of ions were taken into account.…”

Section: Introductionmentioning

confidence: 99%

“…Quasi− −blocking electrode contacts were assumed. The computa− tions were performed by the use of a method described in the previous works [12][13][14][15][16][17][18]. The electric properties of the layer were described in terms of a weak electrolyte model.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Threshold voltages and optical retardation of deformed flexoelectric nematic layers with asymmetric surface anchoring

Derfel

Buczkowska

2013

Opto-Electronics Review

View full text Add to dashboard Cite

Deformations of homeotropically aligned flexoelectric nematic layers induced by dc electric fields were simulated numerically. Two different anchoring strengths on the limiting surfaces were assumed. Nematic material was characterised by negative dielectric anisotropy. Both signs of the sum of flexoelectric coefficients were taken into account. The electric properties of the layer were described in terms of a weak electrolyte model. Mobility of cations was assumed to be one order of magnitude lower than that of anions. Quasi-blocking electrode contacts were assumed. The threshold voltages for deformations were determined by means of calculations of the phase difference Φ between ordinary and extraordinary light rays passing through a layer placed between crossed polarisers. The threshold values depended on the polarity of the bias voltage U. When the threshold value was exceeded, the phase difference increased with the voltage. Two different Φ(U/Uthreshold) dependencies for the two polarities of the voltage were found for each layer if the nematic possessed the flexoelectric properties. The possibility of using this effect to detect the flexoelectricity in the nematic was explored by simulated experiments. The effectiveness of the proposed method is discussed.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Threshold voltages and optical retardation of deformed flexoelectric nematic layers with asymmetric surface anchoring

Derfel

Buczkowska

2013

Opto-Electronics Review

View full text Add to dashboard Cite

show abstract

“…The ions are accumulated at the surfaces leading to the strong subsurface electric fields and field gradients which determine the dielectric and flexo− electric torques. Some aspects of deformations arising in homeotropic layers of flexoelectric nematics were studied numerically in our previous papers [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Analysis of deformations of flexoelectric homeotropic liquid crystal layers with various anchoring strengths

Buczkowska

Derfel

2011

Opto-Electronics Review

View full text Add to dashboard Cite

Deformations of homeotropic layers of nematic liquid crystal possessing flexoelectric properties and subjected to external dc voltage were studied numerically. The influence of the anchoring strengthWwas investigated. The calculations were performed for two types of layers, one with positive dielectric anisotropy and positive sum of flexoelectric coefficients and the other with opposite signs of these parameters. Strongly blocking electrodes were assumed. The threshold voltages for deformations were computed for several anchoring strength values and for low, moderate, and high ion contents. The director distributions were also determined. They were influenced by joined effects of anchoring strength and space charge of ions. For increasing ion contents and increasing anchoring strength, remarkable change of deformation character was noticed. In the case of negative dielectric and flexoelectric parameters, the threshold was nearly proportional to W for low anchoring strength and saturated at some high value of W. In the case of positive dielectric and flexoelectric parameters, the threshold voltage increased strongly with W. In the range of enhanced ion concentrations, the deformation arose in two voltage ranges. The increasing anchoring strength damped the deformations in the whole layer, however, this effect was minor at high ion content.

show abstract

Ion adsorption and external electric field effects on isotropic liquids using a Fermi-like distribution

Almeida

Pereira

Evangelista

2011

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

Influence of ionic transport on deformations of homeotropic nematic layers with positive flexoelectric coefficients

Cited by 21 publications

References 9 publications

Threshold voltages and optical retardation of deformed flexoelectric nematic layers with asymmetric surface anchoring

Threshold voltages and optical retardation of deformed flexoelectric nematic layers with asymmetric surface anchoring

Analysis of deformations of flexoelectric homeotropic liquid crystal layers with various anchoring strengths

Ion adsorption and external electric field effects on isotropic liquids using a Fermi-like distribution

Contact Info

Product

Resources

About