Synthesis of POSS-functionalized liquid crystalline block copolymers via RAFT polymerization for stabilizing blue phase helical soft superstructures

2018 ◽  
Vol 9 (16) ◽  
pp. 2101-2108 ◽  
Author(s):  
Jianqiu Jin ◽  
Mingjie Tang ◽  
Zhenghe Zhang ◽  
Kang Zhou ◽  
Yun Gao ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Block Copolymers ◽  
Liquid Crystalline ◽  
Raft Polymerization ◽  
Phase Liquid ◽  
Blue Phase

A study of the phase transition behaviors of blue phase liquid crystals containing different amounts of POSS-functionalized LC BCPs.

scholarly journals 2-Chloroalkoxy-Substituted Pentafluorinated Bistolanes as Novel Light-Emitting Liquid Crystals

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 195 ◽  
Author(s):  
Shigeyuki Yamada ◽  
Kazuya Miyano ◽  
Tomohiro Agou ◽  
Toshio Kubota ◽  
Tsutomu Konno
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Valuable Insight ◽  
The Novel ◽  
Light Emitting ◽  
Heating And Cooling ◽  
Chiral Nematic ◽  
Blue Phase ◽  
Insight Into

In this study, we designed and synthesized novel pentafluorinated bistolane derivatives with 2-chloropentyl or 2-chlorohexyl flexible units as novel light-emitting liquid crystals (LELCs). By measuring the phase-transition behaviors, all derivatives were found to display liquid-crystalline (LC) phases during both heating and cooling processes. Among the novel bistolanes, the S- and R-configured derivatives exhibited a chiral nematic (N*) phase with a typical Grandjean optical texture. Interestingly, the chiral derivatives also exhibited a blue phase with a typical platelet texture in a narrow temperature range (2–4 °C). Photophysical measurements revealed that the 2-chloroalkoxy-substituted pentafluorinated bistolanes exhibited intense photoluminescence (PL) both in solution and in crystalline phases. The PL characteristics, especially the maximum PL wavelength, were found to switch sensitively during the heating and cooling cycles depending on the molecular aggregates through the crystal (Cr) ⇄ N* phase transition. The 2-chloroalkoxy flexible units induced dynamic changes in the LC and PL properties, providing valuable insight into the potential of various LELCs as PL sensing materials.

Wide-angle lasing from photonic crystal nanostructures of a liquid-crystalline blue phase

2019 ◽  
Vol 7 (21) ◽  
pp. 6433-6439 ◽  
Author(s):  
Guan-Yu Zhuo ◽  
Shu-Wei Huang ◽  
Shih-Hung Lin
Keyword(s):  
Liquid Crystals ◽  
Photonic Crystal ◽  
Photonic Crystals ◽  
Visible Light ◽  
Liquid Crystalline ◽  
Wide Angle ◽  
Phase Liquid ◽  
Blue Phase

Wide-angle lasing emitting dye-doped blue-phase liquid crystals (DDBPLCs), which are analogous to photonic crystals, have been demonstrated to selectively reflect visible light.

scholarly journals Fabrication of the liquid crystalline periodic waveguiding structures by means of the photo-polymerization process

2017 ◽  
Vol 9 (3) ◽  
pp. 82 ◽  
Author(s):  
Bartłomiej Turowski ◽  
Katarzyna Agnieszka Rutkowska
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Polymer Concentration ◽  
Polymerization Process ◽  
Nonlinear Phenomena ◽  
Photo Polymerization ◽  
Photonic Structures ◽  
Phase Liquid ◽  
Blue Phase ◽  
Polymer Stabilized

Photonic structures in a form of the waveguide channels, with periodic spatial changes in refractive index in the wavelength scale, are typically manufactured based on well-developed silica and gallium arsenide technology [1], as well as with use of the high-precision lithography. The main disadvantage related to practical application of such devices is that their optical properties cannot be altered after fabrication. Due to this fact, liquid crystalline periodic waveguiding structures, manufactured with use of the photo-polymerization process, have been proposed in this work. Importantly, propagational characteristic of such photonic structures can be easily adjusted during fabrication procedure, and then may be also dynamically tuned by e.g. applied external voltage, as presented in this communication. Full Text: PDF ReferencesM.J. Ablowitz, Z.H. Musslimani, "Discrete spatial solitons in a diffraction-managed nonlinear waveguide array: a unified approach", Physica D: Nonlinear Phenomena 184(1), 276 (2003). CrossRef L. Vicari, Optical applications of liquid crystals, CRC press, 2016. CrossRef J. Yan, S.-T. Wu, "Effect of Polymer Concentration and Composition on Blue Phase Liquid Crystals", J. Display Technol. 7, 9 (2011). CrossRef J. Schirmer et al., "Birefringence and Refractive Indices Dispersion of Different Liquid Crystalline Structures", Mol. Cryst. Liquid Cryst. 307, 17 (1997). CrossRef D. Xu et al., "Blue phase liquid crystals stabilized by linear photo-polymerization", Appl. Phys. Lett. 105, 8 (2014). CrossRef I. Dierking et al., "Stabilising liquid crystalline Blue Phases", Soft Matter 8, 4355 (2012). CrossRef K. Kang, L.C. Chien, S. Sprunt, "Polymer-stabilized cholesteric liquid crystal microgratings: a comparison of polymer network formation and electro-optic properties for mesogenic and non-mesogenic monomers", Liquid Crystals 29, 9 (2002). CrossRef K.A. Rutkowska, M. Chychłowski, U.A. Laudyn, "Polymer-stabilized periodic waveguiding structures in liquid crystalline materials", Proc. SPIE 10325 (2017). CrossRef

scholarly journals Tunable light beam steering device using polymer stabilized blue phase liquid crystals

2017 ◽  
Vol 9 (1) ◽  
pp. 11 ◽  
Author(s):  
Pankaj Joshi ◽  
Oliver Willekens ◽  
Xiaobing Shang ◽  
Jelle De Smet ◽  
Dieter Cuypers ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Beam Steering ◽  
Polymer Dispersed ◽  
Phase Liquid ◽  
Blue Phase ◽  
Blue Phases ◽  
Polymer Stabilized ◽  
Polarization Independent

A polarization independent and fast electrically switchable beam steering device is presented, based on a surface relief grating combined with polymer stabilized blue phase liquid crystals. Switching on and off times are both less than 2 milliseconds. The prospects of further improvements are discussed. Full Text: PDF ReferencesD.C. Wright, et al., "Crystalline liquids: the blue phases", Rev. Mod. Phys. 61, 385 (1989). CrossRef H. Kikuchi, et al., "Polymer-stabilized liquid crystal blue phases", Nat. Mater. 1, 64 (2002). CrossRef Samsung, Korea, SID exhibition, (2008).J. Yan, et al., "Direct measurement of electric-field-induced birefringence in a polymer-stabilized blue-phase liquid crystal composite", Opt. Express 18, 11450 (2010). CrossRef L. Rao, et al., "A large Kerr constant polymer-stabilized blue phase liquid crystal", Appl. Phys. Lett. 98, 081109 (2011). CrossRef Y. Hisakado, et al., "Large Electro-optic Kerr Effect in Polymer-Stabilized Liquid-Crystalline Blue Phases", Adv. Mater. 17, 96 (2005). CrossRef K. M. et al., "Submillisecond Gray-Level Response Time of a Polymer-Stabilized Blue-Phase Liquid Crystal", J. Disp. Technol. 6, 49 (2010). CrossRef Y. Chen, et al., "Level set based topology optimization for optical cloaks", Appl. Phys. Lett. 102, 251106 (2013). CrossRef H. Choi, et al., "Fast electro-optic switching in liquid crystal blue phase II", Appl. Phys. Lett. 98, 131905 (2011). CrossRef Y.H. Chen, et al., "Polarization independent Fabry-Pérot filter based on polymer-stabilized blue phase liquid crystals with fast response time", Opt. Express 19, 25441 (2011). CrossRef Y. Li, et al., "Polarization independent adaptive microlens with a blue-phase liquid crystal", Opt. Express 19, 8045 (2011). CrossRef C.T. Lee, et al., "Design of polarization-insensitive multi-electrode GRIN lens with a blue-phase liquid crystal", Opt. Express 19, 17402 (2011). CrossRef Y.T. Lin, et al., "Mid-infrared absorptance of silicon hyperdoped with chalcogen via fs-laser irradiation", J. Appl. Phys. 113, (2013). CrossRef J.D. Lin, et al., "Spatially tunable photonic bandgap of wide spectral range and lasing emission based on a blue phase wedge cell", Optics Express 22, 29479 (2014). CrossRef W. Cao, et al., "Lasing in a three-dimensional photonic crystal of the liquid crystal blue phase II", Nat. Mat. 1, 111 (2002). CrossRef S.T. Hur, et al., "Liquid-Crystalline Blue Phase Laser with Widely Tunable Wavelength", Adv. Mater. 25, 3002 (2013). CrossRef A. Mazzulla, et al., "Thermal and electrical laser tuning in liquid crystal blue phase I", Soft. Mater. 8, 4882 (2012). CrossRef C.W. Chen, et al., "Random lasing in blue phase liquid crystals", Opt. Express 20, 23978 (2012). CrossRef O. Willekens, et al., "Ferroelectric thin films with liquid crystal for gradient index applications", Opt. Exp. 24, 8088 (2016). CrossRef O. Willekens, et al., "Reflective liquid crystal hybrid beam-steerer", Opt. Exp. 24, 1541 (2016). CrossRef M. Jazbinšek, et al., "Characterization of holographic polymer dispersed liquid crystal transmission gratings", J. Appl. Phys. 90, 3831 (2001). CrossRef C.C. Bowley, et al., "Variable-wavelength switchable Bragg gratings formed in polymer-dispersed liquid crystals", Appl. Phys. Lett. 79, 9 (2001). CrossRef Y.Q. Lu, et al., "Polarization switch using thick holographic polymer-dispersed liquid crystal grating", Appl. Phys. 95, 810 (2004). CrossRef J.J. Butler et al., "Diffraction properties of highly birefringent liquid-crystal composite gratings", Opt. Lett. 25, 420 (2000). CrossRef R.L. Sutherland et al., "Electrically switchable volume gratings in polymer-dispersed liquid crystals", Appl. Phys. Lett. 64, 1074 (1994). CrossRef X. Shang, et al., "Electrically Controllable Liquid Crystal Component for Efficient Light Steering", IEEE Photo. J. 7, 1 (2015). CrossRef J. Yan, et al., "Extended Kerr effect of polymer-stabilized blue-phase liquid crystals", Appl. Phys. Lett. 96, 071105 (2010). CrossRef H.S. Chen, et al., "Hysteresis-free polymer-stabilized blue phase liquid crystals using thermal recycles", Opt. Mat. Exp. 2, 1149 (2012). CrossRef J. Yan. et al., "Dual-period tunable phase grating using polymer stabilized blue phase liquid crystal", Opt. Lett. 40, 4520 (2015). CrossRef H.S. Chen, et al., "Hysteresis-free polymer-stabilized blue phase liquid crystals using thermal recycles", Opt. Mat. Exp. 2, 1149 (2012). CrossRef H.C. Cheng, et al., "Blue-Phase Liquid Crystal Displays With Vertical Field Switching", J. Disp. Technol. 8, 98 (2012). CrossRef

Textural, phase transition and electro-optic studies of polymer-stabilized blue phase liquid crystals

2019 ◽  
Vol 1188 ◽  
pp. 51-56 ◽  
Author(s):  
Praveen Malik ◽  
Sumit Yadav ◽  
Khushboo
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Electro Optic ◽  
Phase Liquid ◽  
Blue Phase ◽  
Polymer Stabilized

scholarly journals Diffusionless transformation of soft cubic superstructure from amorphous to simple cubic and body-centered cubic phases

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Liu ◽  
Wenzhe Liu ◽  
Bo Guan ◽  
Bo Wang ◽  
Lei Shi ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
X Ray Diffraction ◽  
Photonic Materials ◽  
Simple Cubic ◽  
Cubic Phases ◽  
Transmission Electron ◽  
Phase Liquid ◽  
Blue Phase ◽  
Blue Phases ◽  
Temperature Window

AbstractIn a narrow temperature window in going from the isotropic to highly chiral orders, cholesteric liquid crystals exhibit so-called blue phases, consisting of different morphologies of long, space-filling double twisted cylinders. Those of cubic spatial symmetry have attracted considerable attention in recent years as templates for soft photonic materials. The latter often requires the creation of monodomains of predefined orientation and size, but their engineering is complicated by a lack of comprehensive understanding of how blue phases nucleate and transform into each other at a submicrometer length scale. In this work, we accomplish this by intercepting nucleation processes at intermediate stages with fast cross-linking of a stabilizing polymer matrix. We reveal using transmission electron microscopy, synchrotron small-angle X-ray diffraction, and angle-resolved microspectroscopy that the grid of double-twisted cylinders undergoes highly coordinated, diffusionless transformations. In light of our findings, the implementation of several applications is discussed, such as temperature-switchable QR codes, micro-area lasing, and fabrication of blue phase liquid crystals with large domain sizes.

Thermal phase transition behaviours of the blue phase of bent-core nematogen and chiral dopant mixtures under different boundary conditions

Soft Matter ◽  
2014 ◽  
Vol 10 (41) ◽  
pp. 8224-8228 ◽  
Author(s):  
Min-Jun Gim ◽  
Gohyun Han ◽  
Suk-Won Choi ◽  
Dong Ki Yoon
Keyword(s):  
Phase Transition ◽  
Boundary Conditions ◽  
Liquid Crystalline ◽  
Isotropic Phase ◽  
Different Boundary Conditions ◽  
Various Boundary Conditions ◽  
Thermal Phase Transition ◽  
Thermal Phase ◽  
Blue Phase ◽  
Chiral Dopants

We have investigated dramatic changes in the thermal phase transition of a liquid-crystalline (LC) blue phase (BP) consisting of bent-core nematogen and chiral dopants under various boundary conditions during cooling from the isotropic phase.

Mesophase properties of fluorene-core mesogens and their effects on blue phase liquid crystals

2021 ◽  
pp. 1-11
Author(s):  
Ying Shi ◽  
WanLi He ◽  
YaQian Zhang ◽  
YongFeng Cui ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Phase Liquid ◽  
Blue Phase

Field-induced lattice transformation of blue-phase liquid crystals

2021 ◽  
Author(s):  
Iam-Choon Khoo ◽  
Chun-Wei Chen ◽  
Tsung-Hsien Lin
Keyword(s):  
Liquid Crystals ◽  
Phase Liquid ◽  
Blue Phase

scholarly journals Order Parameters, Orientational Distribution Functions and Heliconical Tilt Angles of Oligomeric Liquid Crystals

2019 ◽  
Author(s):  
Richard Mandle ◽  
John W. Goodby
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Tilt Angle ◽  
Order Parameter ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Thermal Evolution ◽  
Order Parameters ◽  
Distribution Functions ◽  
Orientational Distribution

We compare the order parameters, orientational distribution functions (ODF) and heliconical tilt angles of the TB phase exhibited by a liquid-crystalline dimer (CB7CB) to a tetramer (O47) and hexamer (O67) by SAXS/WAXS. Following the N-TB phase transition we find that all order parameters decrease, and while 〈P2 〉 remains positive 〈P4 〉 becomes negative. For all three materials the order parameter 〈P6 〉 is near zero in both phases. The ODF is sugarloaf-like in the nematic phase and volcano-like in the TB phase, allowing us to estimate the heliconical tilt angle of each material and its thermal evolution. The heliconical tilt angle appears to be largely independent of the material studied despite the differing number of mesogenic units.

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