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Nematic Structures under Conical Anchoring at Various Director Tilt Angles Specified by Polymethacrylate Compositions
Denis A Kostikov1,2, Mikhail N Krakhalev1,2, Oxana O Prishchepa1
1Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk, Russia.
Polymers
|September 10, 2021
Summary
Altering the polymer mixture ratio precisely controls the director tilt angle in nematic liquid crystals (LCs). This tunability is crucial for developing advanced electro-optical LC devices with conical anchoring.
Area of Science:
- Materials Science
- Physics
- Polymer Chemistry
Background:
- Nematic liquid crystals (LCs) exhibit unique optical properties dependent on director alignment.
- Conical anchoring influences director tilt, critical for LC device performance.
- Polymer mixtures offer tunable surface alignment for LCs.
Purpose of the Study:
- To investigate the relationship between polymer mixture composition and director tilt angle in nematic LCs.
- To explore the impact of varying poly(isobutyl methacrylate) (PiBMA) and poly(methylmethacrylate) (PMMA) ratios on LC alignment.
- To assess the potential of these tunable LC systems for electro-optical applications.
Main Methods:
- Fabrication of polymer films with varying PiBMA:PMMA ratios.
- Utilizing an oblique incidence light technique to measure the director tilt angle.
- Optical microscopy to analyze specific optical textures and orientational structures.
- Investigating the effect of electric fields on the formed LC structures.
Main Results:
- Director tilt angle increased from 0° to 47.7° as the PiBMA:PMMA ratio shifted from 30:70 to 100:0.
- Distinct optical textures and orientational structures were observed for different polymer compositions.
- The study demonstrated a direct correlation between polymer blend composition and achievable tilt angles.
Conclusions:
- The director tilt angle of nematic LCs can be effectively controlled by adjusting the composition of PiBMA:PMMA polymer mixtures.
- These findings are highly relevant for designing electro-optical LC devices requiring precise control over director tilt, such as diffraction gratings and polarization rotators.
- The tunable conical anchoring achieved through polymer mixtures opens avenues for novel LC device functionalities.
Keywords:
conical anchoringdirector tilt angledomain wallelectrically-induced reorientationnematic liquid crystalorientational structurepolymethacrylateMore Related Videos
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