Recently several fluorinated molecules have been investigated by many means [1]. We investigated ... more Recently several fluorinated molecules have been investigated by many means [1]. We investigated in details physical properties of two antiferroelectric liquid crystals [2]: MHPB(H)PBC and MHPB(F)PBC. In MHPB(H)PBC paraelectric SmA∗ phase neighbours antiferroelectric SmCA∗ phase, while in MHPB(F)PBC the substitution of fluorine for hydrogen leads to formation of additional narrow ferroelectric phase SmC∗ phase, placed between the mentioned above phases.
The compounds from the fluorinated nF6B (n = 1,2,3,4,5,6,7) homologous series were investigated b... more The compounds from the fluorinated nF6B (n = 1,2,3,4,5,6,7) homologous series were investigated by means of optical, electrooptical, refractometrical, dielectric, densytometric, X-ray and IR spectroscopy methods. For some compounds being a subject of investigations a computer simulation of molecular properties were done. In our opinion high value of optical tilt Θo angle in comparison with a tilt angle obtained from X-ray measurements
In the present work the usefulness of photoalignment as a nematic liquid crystal aligning techniq... more In the present work the usefulness of photoalignment as a nematic liquid crystal aligning technique has been evaluated. A photocrosslinking mechanism of photosensitive polymer material has been used to cause anisotropy in the layer. The influence of the UV dose on the LC alignment of liquid crystal material in the TN-type cell has been examined.
ABSTRACT Optical properties of a nematic liquid crystal with small refractive index and small bir... more ABSTRACT Optical properties of a nematic liquid crystal with small refractive index and small birefringence were studied. The ordinary and extraordinary refractive indices and birefringence were measured as functions of temperature by using an Abbe refractometer and wedge nematic cells. From values of these indices the nematic orientational order parameter was calculated by using several methods and corresponding mathematical models. Kuczyński et al. method was found to be suitable for determining the order parameter also for materials featuring small ordinary refractive index, with unknown density.
The phenomenon of an induction of the chiral anticlinic phase is described. The ability for induc... more The phenomenon of an induction of the chiral anticlinic phase is described. The ability for induction of the antiferroelectric phase of compounds with cyano and fluorinated groups in terminal positions is tested by the comparison of phase diagrams of their mixtures. The results of DSC, electrooptic and X-ray measurements for two systems are presented. The induction of the antiferroelectric phase
Recently several fluorinated molecules have been investigated by many means [1]. We investigated ... more Recently several fluorinated molecules have been investigated by many means [1]. We investigated in details physical properties of two antiferroelectric liquid crystals [2]: MHPB(H)PBC and MHPB(F)PBC. In MHPB(H)PBC paraelectric SmA∗ phase neighbours antiferroelectric SmCA∗ phase, while in MHPB(F)PBC the substitution of fluorine for hydrogen leads to formation of additional narrow ferroelectric phase SmC∗ phase, placed between the mentioned above phases.
The compounds from the fluorinated nF6B (n = 1,2,3,4,5,6,7) homologous series were investigated b... more The compounds from the fluorinated nF6B (n = 1,2,3,4,5,6,7) homologous series were investigated by means of optical, electrooptical, refractometrical, dielectric, densytometric, X-ray and IR spectroscopy methods. For some compounds being a subject of investigations a computer simulation of molecular properties were done. In our opinion high value of optical tilt Θo angle in comparison with a tilt angle obtained from X-ray measurements
In the present work the usefulness of photoalignment as a nematic liquid crystal aligning techniq... more In the present work the usefulness of photoalignment as a nematic liquid crystal aligning technique has been evaluated. A photocrosslinking mechanism of photosensitive polymer material has been used to cause anisotropy in the layer. The influence of the UV dose on the LC alignment of liquid crystal material in the TN-type cell has been examined.
ABSTRACT Optical properties of a nematic liquid crystal with small refractive index and small bir... more ABSTRACT Optical properties of a nematic liquid crystal with small refractive index and small birefringence were studied. The ordinary and extraordinary refractive indices and birefringence were measured as functions of temperature by using an Abbe refractometer and wedge nematic cells. From values of these indices the nematic orientational order parameter was calculated by using several methods and corresponding mathematical models. Kuczyński et al. method was found to be suitable for determining the order parameter also for materials featuring small ordinary refractive index, with unknown density.
The phenomenon of an induction of the chiral anticlinic phase is described. The ability for induc... more The phenomenon of an induction of the chiral anticlinic phase is described. The ability for induction of the antiferroelectric phase of compounds with cyano and fluorinated groups in terminal positions is tested by the comparison of phase diagrams of their mixtures. The results of DSC, electrooptic and X-ray measurements for two systems are presented. The induction of the antiferroelectric phase
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