scholarly journals Electro-induced orientational ordering of anisotropic pigment nanoparticles

2013 ◽  
Vol 371 (1988) ◽  
pp. 20120257 ◽  
Author(s):  
Robert J. Greasty ◽  
Robert M. Richardson ◽  
Susanne Klein ◽  
David Cherns ◽  
Michael R. Thomas ◽  
...  
Keyword(s):  
Electric Fields ◽  
Orientational Order ◽  
Optical Response ◽  
Pigment Particle ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientational Ordering ◽  
Nematic Phases ◽  
High Concentrations ◽  
Ray Scattering

The response of anisotropic pigment particle suspensions to externally applied electric fields has been explored for possible application in reflective display technologies. Three different types of pigment particle were suspended in dodecane, using a polymeric stabilizer, and showed Schlieren textures between crossed polarizers at high concentrations (greater than 25–30 wt%), indicating the formation of colloidal nematic phases. Orientational order parameters were determined by X-ray scattering, and the influence of polydispersity on the values is discussed. X-ray scattering measurements also demonstrated a change in the structure factor consistent with the onset of a colloidal nematic phase. In addition, the pigment particles were dispersed into various liquid crystal hosts at low concentrations (less than 5 wt%) with and without the presence of mesogenic mimic stabilizers. However, the influence of these stabilizers on orientational ordering could not be confirmed. The electro-induced ordering determined via scattering was related to the electro-optical response of each suspension using a simple model. The particles in nematic hosts not only showed a high degree of orientational ordering at lower electric field strengths, but also showed a reduction in stability. Although these systems have shown strong orientational ordering, the optical response has been limited by the intrinsic shape of the pigment particles and the distribution of the transition dipoles moments within them. Nevertheless, the feasibility of developing materials for display applications has been demonstrated.

scholarly journals Optical and X-ray scattering studies of the electric field-induced orientational order in colloidal suspensions of pigment nanorods

2018 ◽  
Vol 267 ◽  
pp. 286-296 ◽  
Author(s):  
Oleksandr Buluy ◽  
Natalie Aryasova ◽  
Oleksandr Tereshchenko ◽  
Yuriy Kurioz ◽  
Vassili Nazarenko ◽  
...  
Keyword(s):  
Electric Field ◽  
Orientational Order ◽  
Colloidal Suspensions ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Orientational order in the splay nematic ground state

2019 ◽  
Vol 21 (34) ◽  
pp. 18769-18772 ◽  
Author(s):  
Richard J. Mandle ◽  
Alenka Mertelj
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Ground State ◽  
Nematic Phase ◽  
Orientational Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

We measure the degree of orientational order in the recently discovered splay-nematic liquid crystal (NS) phase by X-ray scattering techniques. We find the NS phase to be more ordered than the classical nematic phase, although still nematic-like.

Polarized X-ray scattering reveals non-crystalline orientational ordering in organic films

2012 ◽  
Vol 11 (6) ◽  
pp. 536-543 ◽  
Author(s):  
B. A. Collins ◽  
J. E. Cochran ◽  
H. Yan ◽  
E. Gann ◽  
C. Hub ◽  
...  
Keyword(s):  
Organic Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientational Ordering ◽  
Ray Scattering

scholarly journals Fluctuation X-ray scattering from nanorods in solution reveals weak temperature-dependent orientational ordering

IUCrJ ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 635-648 ◽  
Author(s):  
Ruslan P. Kurta ◽  
Lutz Wiegart ◽  
Andrei Fluerasu ◽  
Anders Madsen
Keyword(s):  
Disordered Systems ◽  
Structural Information ◽  
Orientational Order ◽  
Higher Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Isotropic Distribution ◽  
Angle Scattering ◽  
Laser Experiments ◽  
Ray Scattering

Higher-order statistical analysis of X-ray scattering from dilute solutions of polydisperse goethite nanorods was performed and revealed structural information which is inaccessible by conventional small-angle scattering. For instance, a pronounced temperature dependence of the correlated scattering from suspension was observed. The higher-order scattering terms deviate from those expected for a perfectly isotropic distribution of particle orientations, demonstrating that the method can reveal faint orientational order in apparently disordered systems. The observation of correlated scattering from polydisperse particle solutions is also encouraging for future free-electron laser experiments aimed at extracting high-resolution structural information from systems with low particle heterogeneity.

scholarly journals Considerations in the determination of orientational order parameters from X-ray scattering experiments

2018 ◽  
Vol 46 (1) ◽  
pp. 11-24 ◽  
Author(s):  
Mark T. Sims ◽  
Laurence C. Abbott ◽  
Robert M. Richardson ◽  
John W. Goodby ◽  
John N. Moore
Keyword(s):  
Orientational Order ◽  
Order Parameters ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

A Small-Angle X-ray Scattering Study of the Lyotropic Nematic Phase of Vanadium Pentoxide Gels

1997 ◽  
Vol 30 (5) ◽  
pp. 727-732 ◽  
Author(s):  
P. Davidson ◽  
C. Bourgaux ◽  
P. Sergot ◽  
J. Livage
Keyword(s):  
Vanadium Pentoxide ◽  
Small Angle ◽  
Nematic Phase ◽  
Average Distance ◽  
Building Blocks ◽  
X Ray ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Nematic Phases ◽  
Ray Scattering

Aqueous suspensions of vanadium pentoxide (V2O5) ribbons, also called Zocher phases, are known to display a lyotropic nematic phase. In this paper, it is shown how the small-angle X-ray scattering (SAXS) technique can provide useful information on the building blocks and their organization in this phase. SAXS experiments were performed either on unoriented samples or on samples aligned by a magnetic field or by shear flow. The scattering is comparable to that of the other classic lyotropic nematic phases displayed by stiff organic rod-like particles such as the tobacco mosaic virus. Scattering studies show that the building blocks have a ribbon shape, that their thickness is 9 (1) Å and indirectly that their width is several 100 Å. Their length is known to be around a few thousand Å and therefore could not be measured by SAXS. By following the average distance between the ribbons as a function of concentration, it is shown that the swelling of the phase is one-dimensional at large concentrations and two-dimensional at low concentrations. Finally, estimates of the nematic order parameter of a single domain sample and of samples sheared in a Couette cell have been obtained.

Orthogonal smectic and nematic ordering in three-ring polar bent-core molecules with anti-parallel arrangement

2017 ◽  
Vol 41 (13) ◽  
pp. 5403-5411 ◽  
Author(s):  
Supreet Kaur ◽  
Vidhika Punjani ◽  
Golam Mohiuddin ◽  
Santanu Kumar Pal
Keyword(s):  
X Ray ◽  
Nematic Ordering ◽  
X Ray Scattering ◽  
Parallel Arrangement ◽  
Nematic Phases ◽  
Ray Scattering

Three-ring based BLCs exhibiting orthogonal smectic and nematic phases with antiparallel arrangement as derived from SCXRD and X-ray scattering results.

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