Chemically Induced Splay Nematic Phase with Micron Scale Periodicity

X Ray Scattering ◽

Chemically Induced ◽

Crystal Phases ◽

Optical Textures

Nematic liquid crystals lack positional order of their constituent molecules, which share an average orientational order only. Modulated nematic liquid crystal phases also lack positional order, but possess a periodic variation in this direction of average orientation. In the recently discovered splay nematic (NS) phase the average orientational order is augmented with a periodic splay deformation of orientation perpendicular to the director. In this communication we report the first example of a splay nematic phase which is chemically induced by mixing two materials, neither of which exhibit the NS phase. The splay-nematic phase is identified based on its optical textures, X-ray scattering patterns, and small enthalpy of the associated phase transition. We measure the splay periodicity optically, finding it to be ~ 9 μm. This unexpected generation of the splay-nematic phase through binary mixtures offers a new route to materials which exhibit this phase which complements ongoing studies into structure-property relationships and could accelerate the development of technologies utilising this remarkable polar nematic variant.

Nano-Scale Thermo-Mechanical Structure-Property Relationships in Human Dental Tissues Studied by Nanoindentation and Synchrotron X-Ray Scattering

IFMBE Proceedings - The 15th International Conference on Biomedical Engineering ◽

10.1007/978-3-319-02913-9_64 ◽

2014 ◽

pp. 251-254

Author(s):

T. Sui ◽

M. A. Sandholzer ◽

E. L. Bourhis ◽

N. Baimpas ◽

G. Landini ◽

...

Keyword(s):

Structure Property ◽

X Ray ◽

Mechanical Structure ◽

Dental Tissues ◽

Nano Scale ◽

X Ray Scattering ◽

Thermotropic Liquid Crystals Based on Extended 2,5-Disubstituted-1,3,4-Oxadiazoles: Structure–Property Relationships, Variable-Temperature Powder X-ray Diffraction, and Small-Angle X-ray Scattering Studies

Chemistry - An Asian Journal ◽

10.1002/asia.200600252 ◽

2006 ◽

Vol 1 (6) ◽

pp. 814-825 ◽

Cited By ~ 32

Author(s):

Jie Han ◽

Stephen Sin-Yin Chui ◽

Chi-Ming Che

Keyword(s):

Liquid Crystals ◽

Small Angle ◽

Variable Temperature ◽

Structure Property ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Scattering ◽

Thermotropic Liquid Crystals ◽

Hierarchical Structure–Property Relationships in Graft-Type Fluorinated Polymer Electrolyte Membranes Using Small- and Ultrasmall-Angle X-ray Scattering Analysis

Macromolecules ◽

10.1021/ma500111x ◽

2014 ◽

Vol 47 (7) ◽

pp. 2373-2383 ◽

Cited By ~ 18

Author(s):

Tran Duy Tap ◽

Shin-ichi Sawada ◽

Shin Hasegawa ◽

Kimio Yoshimura ◽

Yojiro Oba ◽

...

Keyword(s):

Polymer Electrolyte ◽

Hierarchical Structure ◽

Polymer Electrolyte Membranes ◽

Structure Property ◽

X Ray ◽

Fluorinated Polymer ◽

X Ray Scattering ◽

Electrolyte Membranes ◽

Orientational order in the splay nematic ground state

Physical Chemistry Chemical Physics ◽

10.1039/c9cp03581h ◽

2019 ◽

Vol 21 (34) ◽

pp. 18769-18772 ◽

Cited By ~ 6

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 ◽

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.

Impacts of Organic Sorbates on Ionic Conductivity and Nanostructure of Perfluorinated Sulfonic-Acid Ionomers

10.26434/chemrxiv.14138447.v1 ◽

2021 ◽

Author(s):

Adlai Katzenberg ◽

Andrea Angulo ◽

Ahmet Kusoglu ◽

Miguel Modestino

Keyword(s):

Ionic Conductivity ◽

Domain Structure ◽

Structure Property ◽

X Ray ◽

X Ray Scattering ◽

The Matrix ◽

Fuels And Chemicals ◽

Electrochemical Devices ◽

Perfluorinated Sulfonic Acid

This study provides insights into structure-property relationships of Nafion membranes swollen with organic sorbates, revealing correlations between sorbate polarity, ionomer domain structure, and ionic conductivity. Swelling, nanostructure, and ionic conductivity of Nafion in the presence of short-chain alcohols and alkanes was studied by infrared spectroscopy, X-ray scattering, and voltammetry. Nafion equilibrated with alkanes exhibited negligible uptake and nanoswelling, while alcohols induced nanoscopic- to macroscopic- swelling ratios that increased with alcohol polarity. In mixed-sorbate environments including organics and water, alcohols preserved the overall ionomer domain structure but altered the matrix to enable higher sorbate uptake. Alkanes did not demonstrably alter the hydrated nanostructure or conductivity. Identifying the impacts of organic sorbates on structure-property relationships in ionomers such as Nafion is imperative as membrane-based electrochemical devices find applications in emerging areas ranging from organic fuel cells to the synthesis of fuels and chemicals.

Orientational Order in the Splay Nematic Ground State

10.26434/chemrxiv.8320985.v1 ◽

2019 ◽

Author(s):

Richard Mandle ◽

Alenka Mertelj

Keyword(s):

Liquid Crystalline ◽

Orientational Order ◽

Periodic Variation ◽

Temperature Dependent ◽

X Ray ◽

X Ray Scattering ◽

Significant Interest ◽

Orientational Distribution ◽

Orientational Distribution Function ◽

Liquid Crystalline Material

Modulated nematic liquid crystal phases, which lack positional order but have some periodic variation in the direction of average orientation present in a classical nematic, have attracted significant interest. In the recently discovered splay nematic (NS) phase the average orientational order is augmented with a periodic splay deformation of orientation perpendicular to the director. We use X-ray scattering experiments to measure the orientational order parameters in the nematic (N) and splay nematic (NS) phases of the liquid crystalline material RM734. The degree of orientational order is somewhat larger in the NS phase than in the preceding nematic and temperature dependent. We reconstruct the orientational distribution function and find it to be nematic-like in the NS phase, indicating the change in orientation between neighbouring molecules due to the splay modulation is very small. A small splay angle implies that the splay modulation period is larger than the few tens of nanometers originally envisaged. The method described herein can be used to assist in unambiguous identification of the splay-nematic phase.

Structure of nanoscale-pitch helical phases: blue phase and twist-bend nematic phase resolved by resonant soft X-ray scattering

Soft Matter ◽

10.1039/c7sm00967d ◽

2017 ◽

Vol 13 (38) ◽

pp. 6694-6699 ◽

Cited By ~ 45

Author(s):

Mirosław Salamończyk ◽

Nataša Vaupotič ◽

Damian Pociecha ◽

Cheng Wang ◽

Chenhui Zhu ◽

...

Keyword(s):

Density Distribution ◽

Nematic Phase ◽

Electron Density Distribution ◽

Periodic Structures ◽

Orientational Order ◽

Cholesteric Phase ◽

X Ray ◽

X Ray Scattering ◽

Blue Phase ◽

Periodic structures of phases with orientational order of molecules but homogenous electron density distribution: short pitch cholesteric phase, blue phase and twist-bend nematic phase, were probed by resonant soft X-ray scattering (RSoXS) at the carbon K-edge.

Orientational Order in the Splay Nematic Ground State

10.26434/chemrxiv.8320985 ◽

2019 ◽

Author(s):

Richard Mandle ◽

Alenka Mertelj

Keyword(s):

Liquid Crystalline ◽

Orientational Order ◽

Periodic Variation ◽

Temperature Dependent ◽

X Ray ◽

X Ray Scattering ◽

Significant Interest ◽

Orientational Distribution ◽

Orientational Distribution Function ◽

Liquid Crystalline Material

Modulated nematic liquid crystal phases, which lack positional order but have some periodic variation in the direction of average orientation present in a classical nematic, have attracted significant interest. In the recently discovered splay nematic (NS) phase the average orientational order is augmented with a periodic splay deformation of orientation perpendicular to the director. We use X-ray scattering experiments to measure the orientational order parameters in the nematic (N) and splay nematic (NS) phases of the liquid crystalline material RM734. The degree of orientational order is somewhat larger in the NS phase than in the preceding nematic and temperature dependent. We reconstruct the orientational distribution function and find it to be nematic-like in the NS phase, indicating the change in orientation between neighbouring molecules due to the splay modulation is very small. A small splay angle implies that the splay modulation period is larger than the few tens of nanometers originally envisaged. The method described herein can be used to assist in unambiguous identification of the splay-nematic phase.