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Light scattering study of the “pseudo-layer” compression elastic constant in a twist-bend nematic liquid crystal (2016)
Journal Article
Parsouzi, Z., Pardaev, S. A., Welch, C., Ahmed, Z., Mehl, G. H., Baldwin, A. R., …Sprunt, S. (2016). Light scattering study of the “pseudo-layer” compression elastic constant in a twist-bend nematic liquid crystal. Physical chemistry chemical physics : PCCP, 18(46), 31645-31652. https://doi.org/10.1039/C6CP06292J

The nematic twist-bend (TB) phase, exhibited by certain achiral thermotropic liquid crystalline (LC) dimers, features a nanometer-scale, heliconical rotation of the average molecular long axis (director) with equally probable left- and right-handed d... Read More about Light scattering study of the “pseudo-layer” compression elastic constant in a twist-bend nematic liquid crystal.

Comparative analysis of anisotropic material properties of uniaxial nematics formed by flexible dimers and rod-like monomers (2016)
Journal Article
Cukrov, G., Mosaddeghian Golestani, Y., Xiang, J., Nastishin, Y. A., Ahmed, Z., Welch, C., …Lavrentovich, O. D. (2017). Comparative analysis of anisotropic material properties of uniaxial nematics formed by flexible dimers and rod-like monomers. Liquid crystals, 44(1), 219-231. https://doi.org/10.1080/02678292.2016.1240248

We report temperature dependencies of material properties such as dielectric anisotropy, birefringence, splay (K₁₁), twist (K₂₂), and bend (K₃₃) elastic constants of the uniaxial nematic (N) phase formed by flexible dimers of DTC5C9 and compare their... Read More about Comparative analysis of anisotropic material properties of uniaxial nematics formed by flexible dimers and rod-like monomers.

Deuteron and proton NMR study of D₂, p-dichlorobenzene and 1,3,5-trichlorobenzene in bimesogenic liquid crystals with two nematic phases (2016)
Journal Article
Burnell, E. E., Ahmed, Z., Welch, C., Mehl, G. H., & Dong, R. Y. (2016). Deuteron and proton NMR study of D₂, p-dichlorobenzene and 1,3,5-trichlorobenzene in bimesogenic liquid crystals with two nematic phases. Chemical Physics Letters, 659, 48-54. https://doi.org/10.1016/j.cplett.2016.07.005

The solutes dideuterium, 1,3,5-trichlorobenzene and p-dichlorobenzene (pdcb) are co-dissolved in a 61/39 wt% mixture of CBC9CB/5CB, a bimesogenic liquid crystal with two nematic phases. NMR spectra are collected for each solute. The local electric fi... Read More about Deuteron and proton NMR study of D₂, p-dichlorobenzene and 1,3,5-trichlorobenzene in bimesogenic liquid crystals with two nematic phases.

Mesophase structure and behaviour in bulk and restricted geometry of a dimeric compound exhibiting a nematic-nematic transition (2016)
Journal Article
Sebastián, N., Tamba, M. G., Stannarius, R., de la Fuente, M. R., Salamonczyk, M., Cukrov, G., …Eremin, A. (2016). Mesophase structure and behaviour in bulk and restricted geometry of a dimeric compound exhibiting a nematic-nematic transition. Physical chemistry chemical physics : PCCP, 18(28), 19299-19308. https://doi.org/10.1039/c6cp03899a

We present structural studies of a dimeric compound composed of a central heptyl spacer linking two mesogens consisiting of terphenyl units at which two adjacent fluoro groups are attached to each central ring. The terminal rings are linked to pentyl... Read More about Mesophase structure and behaviour in bulk and restricted geometry of a dimeric compound exhibiting a nematic-nematic transition.

Fluctuation modes of a twist-bend nematic liquid crystal (2016)
Journal Article
Parsouzi, Z., Shamid, S. M., Borshch, V., Challa, P. K., Baldwin, A. R., Tamba, M. G., …Sprunt, S. (2016). Fluctuation modes of a twist-bend nematic liquid crystal. Physical Review X, 6(2), 021041-1-021041-16. https://doi.org/10.1103/PhysRevX.6.021041

We report a dynamic light-scattering study of the fluctuation modes in a thermotropic liquid crystalline mixture of monomer and dimer compounds that exhibits the twist-bend nematic (NTB) phase. The results reveal a spectrum of overdamped fluctuations... Read More about Fluctuation modes of a twist-bend nematic liquid crystal.

Anomalous increase in nematic-isotropic transition temperature in dimer molecules induced by magnetic field (2016)
Journal Article
Salili, S. M., Tamba, M. G., Sprunt, S. N., Welch, C., Mehl, G. H., Jákli, A., & Gleeson, J. T. (2016). Anomalous increase in nematic-isotropic transition temperature in dimer molecules induced by magnetic field. Physical review letters, 116(21-27 May), Article 217801. https://doi.org/10.1103/PhysRevLett.116.217801

We have determined the nematic-isotropic transition temperature as a function of applied magnetic field in three different thermotropic liquid crystalline dimers. These molecules are comprised of two rigid calamitic moieties joined end to end by flex... Read More about Anomalous increase in nematic-isotropic transition temperature in dimer molecules induced by magnetic field.

Second harmonic light scattering induced by defects in the twist-bend nematic phase of liquid crystal dimers (2016)
Journal Article
Pardaev, S. A., Shamid, S. M., Tamba, M. G., Welch, C., Mehl, G. H., Gleeson, J. T., …Sprunt, S. (2016). Second harmonic light scattering induced by defects in the twist-bend nematic phase of liquid crystal dimers. Soft matter, 12(19), 4472-4482. https://doi.org/10.1039/c6sm00585c

The nematic twist-bend (NTB) phase, exhibited by certain thermotropic liquid crystalline (LC) dimers, represents a new orientationally ordered mesophase -- the first distinct nematic variant discovered in many years. The NTB phase is distinguished by... Read More about Second harmonic light scattering induced by defects in the twist-bend nematic phase of liquid crystal dimers.

The stabilisation of the Nx phase in mixtures (2016)
Journal Article
Ramou, E., Ahmed, Z., Welch, C., Karahaliou, P. K., & Mehl, G. H. (2016). The stabilisation of the Nx phase in mixtures. Soft matter, 12(3), 888-899. https://doi.org/10.1039/c5sm01961c

The phase behaviour of mixtures between two symmetric dimers, CBC9CB and the ether-linked analogue CBOC9OCB was investigated by Polarizing Optical Microscopy (POM), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD) studies. The dime... Read More about The stabilisation of the Nx phase in mixtures.