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Journal articles on the topic 'Nematic hydrogel'

Author: Grafiati

Published: 4 June 2021

Last updated: 16 February 2022

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1

Gwon, So-Jeong, and Soo-Young Park. "General method for the production of hydrogel droplets from uniformly sized smart shell membranes." Polymer Chemistry 11, no. 34 (2020): 5444–54. http://dx.doi.org/10.1039/d0py00679c.

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A smart solid-state liquid crystal shell membrane template prepared by a microfluidic method with a reactive mesogen mixture doped with a nematic liquid crystal of 5CB as a porogen was used for a facile and general method to produce uniformly sized hydrogel droplets.

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2

Bertsch, Pascal, Stéphane Isabettini, and Peter Fischer. "Ion-Induced Hydrogel Formation and Nematic Ordering of Nanocrystalline Cellulose Suspensions." Biomacromolecules 18, no. 12 (October 20, 2017): 4060–66. http://dx.doi.org/10.1021/acs.biomac.7b01119.

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3

Li, Chuang, Garrett C. Lau, Hang Yuan, Aaveg Aggarwal, Victor Lopez Dominguez, Shuangping Liu, Hiroaki Sai, et al. "Fast and programmable locomotion of hydrogel-metal hybrids under light and magnetic fields." Science Robotics 5, no. 49 (December 9, 2020): eabb9822. http://dx.doi.org/10.1126/scirobotics.abb9822.

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The design of soft matter in which internal fuels or an external energy input can generate locomotion and shape transformations observed in living organisms is a key challenge. Such materials could assist in productive functions that may range from robotics to smart management of chemical reactions and communication with cells. In this context, hydrated matter that can function in aqueous media would be of great interest. Here, we report the design of hydrogels containing a scaffold of high–aspect ratio ferromagnetic nanowires with nematic order dispersed in a polymer network that change shape in response to light and experience torques in rotating magnetic fields. The synergistic response enables fast walking motion of macroscopic objects in water on either flat or inclined surfaces and also guides delivery of cargo through rolling motion and light-driven shape changes. The theoretical description of the response to the external energy input allowed us to program specific trajectories of hydrogel objects that were verified experimentally.

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4

Nack, Annemarie, Julian Seifert, Christopher Passow, and Joachim Wagner. "Hindered nematic alignment of hematite spindles in poly(N-isopropylacrylamide) hydrogels: a small-angle X-ray scattering and rheology study." Journal of Applied Crystallography 51, no. 1 (February 1, 2018): 87–96. http://dx.doi.org/10.1107/s1600576717017411.

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Field-induced changes to the mesostructure of ferrogels consisting of spindle-shaped hematite particles and poly(N-isopropylacrylamide) are investigated by means of small-angle X-ray scattering (SAXS). Related field-induced changes to the macroscopic viscoelastic properties of these composites are probed by means of oscillatory shear experiments in an external magnetic field. Because of their magnetic moment and magnetic anisotropy, the hematite spindles align with their long axis perpendicular to the direction of an external magnetic field. The field-induced torque acting on the magnetic particles leads to an elastic deformation of the hydrogel matrix. Thus, the field-dependent orientational distribution functions of anisotropic particles acting as microrheological probes depend on the elastic modulus of the hydrogel matrix. The orientational distribution functions are determined by means of SAXS experiments as a function of the varying flux density of an external magnetic field. With increasing elasticity of the hydrogels, tunedviathe polymer volume fraction and the crosslinking density, the field-induced alignment of these anisotropic magnetic particles is progressively hindered. The microrheological results are in accordance with macrorheological experiments indicating increasing elasticity with increasing flux density of an external field.

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5

Pei, Xiaodong, Tingting Zan, Hengming Li, Yingjun Chen, Linqi Shi, and Zhenkun Zhang. "Pure Anisotropic Hydrogel with an Inherent Chiral Internal Structure Based on the Chiral Nematic Liquid Crystal Phase of Rodlike Viruses." ACS Macro Letters 4, no. 11 (October 21, 2015): 1215–19. http://dx.doi.org/10.1021/acsmacrolett.5b00677.

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6

Walker, Rebecca, Damian Pociecha, Alfonso Martinez-Felipe, John MD Storey, Ewa Gorecka, and Corrie T. Imrie. "Twist-Bend Nematogenic Supramolecular Dimers and Trimers Formed by Hydrogen Bonding." Crystals 10, no. 3 (March 6, 2020): 175. http://dx.doi.org/10.3390/cryst10030175.

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A selection of novel non-symmetric supramolecular liquid crystal dimers and trimers formed by hydrogen-bonding have been prepared and their phase behaviour characterised by polarised optical microscopy, X-ray diffraction and temperature-dependent Fourier-transform infrared spectroscopy. We mix the bent twist-bend nematogen 4-[6-(4’-cyanobiphenyl-4-yl) hexyloxy]-benzoic acid (CB6OBA) with a series of small stilbazole-based compounds 4-[(E)-2-(n-alkoxyphenyl)ethenyl]pyridines (nOS) of varying terminal chain length (n) to obtain the CB6OBA:nOS complexes. Complexes with n ≤ 7 exhibit nematic and twist-bend nematic behaviour, followed on cooling by a smectic C phase for n = 4–7, and finally, a hexatic-type smectic X phase for n = 3–7. Mixtures with n = 8–10 exhibit a smectic A phase below the conventional nematic phase, and on further cooling, a biaxial smectic Ab phase and the same hexatic-type SmX phase. Supramolecular trimers, CB6OBA:CB6OS and CB6OBA:1OB6OS, formed between CB6OBA and dimeric stilbazoles [(E)-2-(4-{[6-(4’-methoxy[1,1’-biphenyl]-4-yl)hexyl]oxy}phenyl)ethenyl]pyridine (1OB6OS) or 4-[(E)-4’-(6-{4-[(E)-2-(pyridin-4-yl)ethenyl]phenoxy}hexyl)[1,1’-biphenyl]-4- carbonitrile (CB6OS), exhibit nematic and twist-bend nematic phases, and are the first hydrogen-bonded trimers consisting of unlike donor and acceptor fragments to do so.

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7

Okumuş, Mustafa. "Investigation of thermal and optical properties of some quartet mixed hydrogen-bonded liquid crystals." International Journal of Modern Physics B 31, no. 29 (November 7, 2017): 1750224. http://dx.doi.org/10.1142/s0217979217502241.

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In this study, the thermal and optical properties of quartet mixtures formed at different weight ratios (1:1:1:1 and 1.5:1:1:1) from liquid crystals 4-octyloxy-4[Formula: see text]-cyanobiphenyl (8OCB), 4-hexylbenzoic acid, 4-(octyloxy)benzoic acid and 4-(decyloxy)benzoic acid were investigated by differential scanning calorimeter (DSC) and polarized optic microscopy (POM). The phase transition temperatures of the novel quartet mixtures measured in the DSC experiments are in line with the POM experiments. The experimental results clearly show that the novel liquid crystal mixtures have displayed pure liquid crystalline properties. According to the phase diagram drawn from DSC results, the nematic range of the novel mixture at the eutectic point is larger than the nematic ranges of the components. The mesomorphic structures of produced homolog complex mixtures are found to be smectic and nematic phases. But the smectic phase cannot be observed in the novel complex 1.5:1:1:1 mixture during continuous cooling. The nematic range of the novel complex 1.5:1:1:1 mixture is bigger than the nematic range of the novel complex 1:1:1:1 mixture with increasing 8OCB. Also, the nematic-to-isotropic phase transition temperature decreases with increasing the weight ratio of 8OCB in the complex quartet mixture. Another interesting result is that the produced mixtures are to be like a medical cream at room temperatures. Furthermore, order parameter and thermal stability factor of the transitions are also calculated.

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8

Hiratani, Takayuki, Osamu Kose, Wadood Y. Hamad, and Mark J. MacLachlan. "Stable and sensitive stimuli-responsive anisotropic hydrogels for sensing ionic strength and pressure." Materials Horizons 5, no. 6 (2018): 1076–81. http://dx.doi.org/10.1039/c8mh00586a.

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9

Fu, Dengwei, Juntao Li, Jie Wei, and Jinbao Guo. "Effects of terminal chain length in hydrogen-bonded chiral switches on phototunable behavior of chiral nematic liquid crystals: helicity inversion and phase transition." Soft Matter 11, no. 15 (2015): 3034–45. http://dx.doi.org/10.1039/c5sm00128e.

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10

Giese, Michael, Tim Krappitz, Ronald Y. Dong, Carl A. Michal, Wadood Y. Hamad, Brian O. Patrick, and Mark J. MacLachlan. "Tuning the photonic properties of chiral nematic mesoporous organosilica with hydrogen-bonded liquid-crystalline assemblies." Journal of Materials Chemistry C 3, no. 7 (2015): 1537–45. http://dx.doi.org/10.1039/c4tc02602k.

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The thermochromic behaviour of chiral nematic mesoporous organosilica hybrids infiltrated with hydrogen-bonded liquid crystals was investigated by polarized optical microscopy, UV-vis and CD-spectroscopy.

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11

Burmistrov, V. A., V. V. Aleksandriiskii, I. V. Novikov, and O. I. Koifman. "Mechanisms of Chiral Transfer in Optically Active Dopant – Nematic Liquid Crystal Systems." Liquid Crystals and their Application 20, no. 4 (December 29, 2020): 6–26. http://dx.doi.org/10.18083/lcappl.2020.4.6.

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Induction of helical mesophases by incorporating chiral dopants into the nematics matrix is the promising modern trends in the chemistry of liquid crystals. This process is associated with a unique phenomenon - an amplification of chirality in liquid-crystalline phases, which ensures the detection of enantiomers by their chiral induction, much more sensitive than other methods. The relevance of this approach is due to the need to create perspective electro-optical devices operating with ultra-low control voltages based on twist effects, chromatographic stationary phases with high chiral selectivity, flexible magnets, photo-sensitive nanostructures, and other smart LC materials. The successful solution of these problems is impossible without experimental research and theoretical comprehension of the mechanisms of third level chiral transfer optically active dopant – nematic liquid crystal. In the last decade, a large number of works have appeared on the solution of these problems. This review is devoted to a generalization of the experimental results and a theoretical description of the transfer of molecular chirality to orientationally ordered systems with the participation of both chiral molecular substituents with an asymmetric carbon atom and planar or quasi-planar fragments chirally distorted relative to each other. The stereochemical aspects of induction associated with the structural correspondences of the dopant and nematic liquid crystal, as well as the main classes of optically active additives, are discussed. Application of metal complexes, both Werner and macroheterocyclic, are presented. Special attention is paid to the results of the mechanisms study of chiral transfer due to various intermolecular interactions: hydrogen bonding, axial coordination, and the formation of inclusion compounds. The high efficiency of induction of spiral mesophases has been demonstrated with a combination of different self-assembly mechanisms in liquid crystal - chiral additive systems.

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12

Mejia, Andres F., Ratna Ng, Peter Nguyen, Min Shuai, Hugo Y. Acosta, M. Sam Mannan, and Zhengdong Cheng. "Thermo-responsive discotic nematic hydrogels." Soft Matter 9, no. 43 (2013): 10257. http://dx.doi.org/10.1039/c3sm51358k.

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13

Ahmed, H. A., M. Hagar, and A. Aljuhani. "Mesophase behavior of new linear supramolecular hydrogen-bonding complexes." RSC Advances 8, no. 61 (2018): 34937–46. http://dx.doi.org/10.1039/c8ra07692h.

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14

Walker, Rebecca, Damian Pociecha, Mirosław Salamończyk, John M. D. Storey, Ewa Gorecka, and Corrie T. Imrie. "Supramolecular liquid crystals exhibiting a chiral twist-bend nematic phase." Materials Advances 1, no. 6 (2020): 1622–30. http://dx.doi.org/10.1039/d0ma00302f.

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The characterisation of a selection of novel, chiral supramolecular liquid crystals formed by hydrogen-bonding is reported; these are the first examples of the chiral twist-bend nematic phase (N*TB) induced by H-bonding through molecular recognition.

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15

Novikov, I. V., V. V. Aleksandriiskii, V. A. Burmistrov, and O. I. Koifman. "Influence of 4-(2-S(+)-Methylbutyloxy)Benzoic Acid on Mesomorphic and Physico-Chemical Properties of 4-Butyl-4'-Octanoyloxyazobenzene." Liquid Crystals and their Application 20, no. 4 (December 29, 2020): 45–53. http://dx.doi.org/10.18083/lcappl.2020.4.45.

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Mesomorphic, optical, dielectric, and orientation properties of nematic liquid crystal 4-butyl-4'-octanoyloxyazobenzene doped with chiral 4-(2-S(+)-methylbutyloxy)benzoic acid have been studied. The clearing temperatures of the mixtures were measured by polarizing microscopy. An estimation of the mesophase destabilization with the introduction of the dopant was carried out. The helix pitch of the induced chiral nematic mesophase was measured. The effect of the chiral dopant on anisotropic characteristics of the mesophase has been studied. An insignificant increase in the optical and dielectric anisotropy is associated with the formation of liquid crystal – dopant supermolecules due to hydrogen bonds –COOH…OCO–.

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16

Trang, Châu Thể Liễu, Đặng Thị Thanh Nhàn, Lê Thị Hòa, and Nguyễn Đức Cường. "CHITIN LIQUID CRYSTAL- DERIVED SPONGE- LIKE AEROGEL." Hue University Journal of Science: Natural Science 127, no. 1A (June 6, 2018): 83. http://dx.doi.org/10.26459/hueuni-jns.v127i1a.4509.

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<p class="RSCB01COMAbstract"><span class="06CHeading"><span lang="EN-GB">Abstract: </span></span><span lang="EN-GB">Chitin nanocrystals in anisotropic liquid crystals have been used as a colloidal precursor to fabricate hydrogels and aerogels. Native chitin nanofibrils are deacetylated and hydrolyzed to generate rod-shaped chitin nanocrystals that are dispersible in water to form colloidal aqueous suspensions. Chitin nanocolloids self-organize into anisotropic liquid crystals that can solidify into layered nematic films. Chitin liquid crystals are hydrothermally gelatinized with formaldehyde crosslinkers to form homogeneous chitin hydrogels. The removal of water in the hydrogels by freeze-drying recovers ultralight chitin sponge-like aerogels with morphological retention of layered nematic chitin structure. These biocompatible chitin aerogels hold promise for developing advanced functional materials such as fabrics for antibacterial bandages and tissue engineering and hydrophobic absorbents for oil/water separation. Potentially, chitin nanocrystals assembled in the aerogels may be functionalized into hydrophobic sponges for oil/water separation or carbonized into nitrogen-doped carbon foams for supercapacitors.</span></p>

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17

Kornreich, M., E. Malka-Gibor, A. Laser-Azogui, O. Doron, H. Herrmann, and R. Beck. "Composite bottlebrush mechanics: α-internexin fine-tunes neurofilament network properties." Soft Matter 11, no. 29 (2015): 5839–49. http://dx.doi.org/10.1039/c5sm00662g.

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We measure the mechano-elastic properties of composite bottlebrush nematic hydrogels consisting of proteins originated from the central nervous system. We show that intra-brush interactions fine-tunes the network structure which may serve as a structural-regulatory mechanism in neuronal early developmental stages.

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18

Ramya, A., V. Balasubramanian, R. Jayaprakasam, and V. N. Vijayakumar. "Observation of Induced Luminescence and Thermochromism in Achiral Hydrogen Bonded Liquid Crystal Complexes." Zeitschrift für Physikalische Chemie 234, no. 10 (October 25, 2020): 1709–33. http://dx.doi.org/10.1515/zpch-2020-1602.

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AbstractA novel hydrogen bonded liquid crystal (HBLC) complexes are obtained from the non-mesogenic (benzylmalonic acid) and mesogenic (p-n-alkyloxybenzoic acid, where n = 6, 7 and 8) compound via intermolecular hydrogen bonds (H-bond). H-bonds are experimentally confirmed by the Fourier transform infrared spectroscopic (FT-IR) studies and the same is validated using density functional theory (DFT). Induced thermochromism is observed by the polarizing optical microscope (POM) and its possible applications are reported. Phase transition temperature and their analogous enthalpy values, stability factor and span width are determined by the differential scanning calorimetry (DSC) studies. Band gap energy is calculated using UV-visible and photoluminescence spectrum. Hyper conjugative stabilization energy and atomic charge distribution is studied by the natural bond orbital (NBO) studies. Mulliken analysis clearly reveals the intermolecular interaction and steric effect of the HBLC complexes. An interesting phenomenon is that the observation of luminescence and thermochromism in the highly fluidity nematic phase. This peculiar behavior is attributed due to the intermolecular H-bonding interaction between the BMA and nOBA compounds and the effect of rotatory motion of the molecules in nematic phase. Luminescence increases when the spacer moiety decreases in the present complexes is also reported. In nematic phase, the molecules are in different degrees of the excited state which is correlated with the hyper conjugative energy through NBO studies.

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19

Ahmed, Hoda, Mohamed Hagar, and Omaima Alhaddad. "Phase Behavior and DFT Calculations of Laterally Methyl Supramolecular Hydrogen-Bonding Complexes." Crystals 9, no. 3 (March 6, 2019): 133. http://dx.doi.org/10.3390/cryst9030133.

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Four new series of laterally methyl-substituted hydrogen-bonded supramolecular complexes were prepared. The prepared complexes were thermally investigated by differential scanning calorimetry (DSC) and phases identified by polarized light microscopy (PLM). Supramolecular hydrogen-bonded complexes formed from a 1:1 mixture of any two derivatives, bearing different alkoxy chains, of 4-alkoxyphenylazobenzoic acid and 4-(2-(pyridin-4-yl)diazenyl-(2-(or 3-)methylphenyl) 4-alkoxybenzoate. The investigated 1:1 mixture made by introducing a lateral methyl group by different spatial orientation angles into pyridine-based components. All new complexes were confirmed by Fourier-transform infrared spectroscopy (FTIR) and computational calculations used to study their stabilities. It is found that the prepared complexes are dimorphic, exhibiting smectic C and enhanced nematic phases. A comparison was made between the new series and previously investigated simpler complexes, revealed that the incorporation of the phenylazo group elongate the mesogenic part and hence broad nematic phases were obtained with high stability.

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20

Li, Ying, Liang Zhang, and Meng Jie Chang. "Cholesteric Cyclohexane-Containing Side-Chain Liquid-Crystalline Polysiloxanes." Materials Science Forum 809-810 (December 2014): 308–12. http://dx.doi.org/10.4028/www.scientific.net/msf.809-810.308.

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Two new kinds of Cholesteric cyclohexane-Containing Side-Chain Liquid-Crystalline Polysiloxanes (PAand PB) were synthesized via hydrosilylation reaction of polymethyl hydrogen siloxane with cyclohexane mesogenic monomers (MAand MB). The yield of PA, PBwere 71.6%, 82.5% and 81.0%, respectively. The molecular structures of MAand MB, PAand PBwere investigated by Fourier transform infrared spectroscopy (FTIR) and hydrogen-nuclear magnetic resonance spectra (1H-NMR). The corresponding liquid crystalline phase type was also observed by polarizing optical microscopy (POM) and X-ray diffraction (XRD). The liquid crystalline phase behavior and thermal properties of the polymers were analyzed by differential scanning calorimetry (DSC). Results showed that MAand MBexhibited multicolor platelet texture of a blue phase and cholesteric phase, and the Tmand Tiof MAand MBincreased with the increasing flexible chain length. The mesophase temperature range of PAand PBwas broader than that of MAand MB. PAexhibited a rare nematic phase----spherulite texture of polymeric smectic A phase. PBwere of cholesteric and nematic---- cholesteric phase. The Tmand Tiof PAand PBincreased with the increasing flexible spacer groups.

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21

Ahmed, H. A., M. Hagar, M. Alaasar, and M. Naoum. "Wide nematic phases induced by hydrogen-bonding." Liquid Crystals 46, no. 4 (September 4, 2018): 550–59. http://dx.doi.org/10.1080/02678292.2018.1512664.

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22

Sear, Richard P., and George Jackson. "Theory for hydrogen-bonding nematic liquid crystals." Molecular Physics 82, no. 3 (June 20, 1994): 473–85. http://dx.doi.org/10.1080/00268979400100354.

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23

Mallia, V. Ajay, P. K. Sudhadevi Antharjanam, and Suresh Das. "Chiral Nematic Glasses from Novel Hydrogen-Bonded Mesogens." Chemistry Letters 30, no. 8 (August 2001): 752–53. http://dx.doi.org/10.1246/cl.2001.752.

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24

Jansze, Suzanne M., Alfonso Martínez-Felipe, John M. D. Storey, Antonius T. M. Marcelis, and Corrie T. Imrie. "A Twist-Bend Nematic Phase Driven by Hydrogen Bonding." Angewandte Chemie 127, no. 2 (November 17, 2014): 653–56. http://dx.doi.org/10.1002/ange.201409738.

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25

Aggeli, Amalia, Mark Bell, Neville Boden, Lisa M. Carrick, and Andrew E. Strong. "Self-Assembling Peptide Polyelectrolyteβ-Sheet Complexes Form Nematic Hydrogels." Angewandte Chemie 115, no. 45 (November 24, 2003): 5761–64. http://dx.doi.org/10.1002/ange.200352207.

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26

Nguyen, Thanh-Dinh, Bernardo U. Peres, Ricardo M. Carvalho, and Mark J. MacLachlan. "Photonic Hydrogels from Chiral Nematic Mesoporous Chitosan Nanofibril Assemblies." Advanced Functional Materials 26, no. 17 (March 15, 2016): 2875–81. http://dx.doi.org/10.1002/adfm.201505032.

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27

Aggeli, Amalia, Mark Bell, Neville Boden, Lisa M. Carrick, and Andrew E. Strong. "Self-Assembling Peptide Polyelectrolyteβ-Sheet Complexes Form Nematic Hydrogels." Angewandte Chemie International Edition 42, no. 45 (November 24, 2003): 5603–6. http://dx.doi.org/10.1002/anie.200352207.

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28

van der Est, Arthur J., E. Elliot Burnell, and Juhani Lounila. "Molecular hydrogen in nematic liquid crystals. Unusual isotope effects." Journal of the Chemical Society, Faraday Transactions 2 84, no. 8 (1988): 1095. http://dx.doi.org/10.1039/f29888401095.

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29

Wu, Zhen, and Zheng Zhong. "A theoretical model for striped patterns in nematic hydrogels." Chinese Science Bulletin 56, no. 17 (May 25, 2011): 1778–81. http://dx.doi.org/10.1007/s11434-011-4495-y.

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30

Yu, Huaizhe, Kunlun Wang, Tibor Szilvási, Karthik Nayani, Nanqi Bao, Robert J. Twieg, Manos Mavrikakis, and Nicholas L. Abbott. "Design of Chemoresponsive Soft Matter Using Hydrogen-Bonded Liquid Crystals." Materials 14, no. 5 (February 24, 2021): 1055. http://dx.doi.org/10.3390/ma14051055.

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Soft matter that undergoes programmed macroscopic responses to molecular analytes has potential utility in a range of health and safety-related contexts. In this study, we report the design of a nematic liquid crystal (LC) composition that forms through dimerization of carboxylic acids and responds to the presence of vapors of organoamines by undergoing a visually distinct phase transition to an isotropic phase. Specifically, we screened mixtures of two carboxylic acids, 4-butylbenzoic acid and trans-4-pentylcyclohexanecarboxylic acid, and found select compositions that exhibited a nematic phase from 30.6 to 111.7 °C during heating and 110.6 to 3.1 °C during cooling. The metastable nematic phase formed at ambient temperatures was found to be long-lived (>5 days), thus enabling the use of the LC as a chemoresponsive optical material. By comparing experimental infrared (IR) spectra of the LC phase with vibrational frequencies calculated using density functional theory (DFT), we show that it is possible to distinguish between the presence of monomers, homodimers and heterodimers in the mixture, leading us to conclude that a one-to-one heterodimer is the dominant species within this LC composition. Further support for this conclusion is obtained by using differential scanning calorimetry. Exposure of the LC to 12 ppm triethylamine (TEA) triggers a phase transition to an isotropic phase, which we show by IR spectroscopy to be driven by an acid-base reaction, leading to the formation of ammonium carboxylate salts. We characterized the dynamics of the phase transition and found that it proceeds via a characteristic spatiotemporal pathway involving the nucleation, growth, and coalescence of isotropic domains, thus amplifying the atomic-scale acid-base reaction into an information-rich optical output. In contrast to TEA, we determined via both experiment and computation that neither hydrogen bonding donor or acceptor molecules, such as water, dimethyl methylphosphonate, ethylene oxide or formaldehyde, disrupt the heterodimers formed in the LC, hinting that the phase transition (including spatial-temporal characteristics of the pathway) induced in this class of hydrogen bonded LC may offer the basis of a facile and chemically selective way of reporting the presence of volatile amines. This proposal is supported by exploratory experiments in which we show that it is possible to trigger a phase transition in the LC by exposure to volatile amines emitted from rotting fish. Overall, these results provide new principles for the design of chemoresponsive soft matter based on hydrogen bonded LCs that may find use as the basis of low-cost visual indicators of chemical environments.

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31

Vanakaras, A. G., S. C. Mcgrother, G. Jackson, and D. J. Photinos. "Hydrogen-bonding and Phase Biaxiality in Nematic Rod-Plate Mixtures." Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 323, no. 1 (December 1998): 199–209. http://dx.doi.org/10.1080/10587259808048442.

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32

Yoshida, Shingo, Takatomo Narui, Kazunori Asaba, Junichi Kawata, and Shunsuke Kobinata. "Phase Behavior of Nematic-Nonnematic Binary Systems–Effects of Hydrogen Bonding–." Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 301, no. 1 (August 1997): 425–30. http://dx.doi.org/10.1080/10587259708041798.

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33

Alaasar, Mohamed, and Carsten Tschierske. "Nematic phases driven by hydrogen-bonding in liquid crystalline nonsymmetric dimers." Liquid Crystals 46, no. 1 (May 21, 2018): 124–30. http://dx.doi.org/10.1080/02678292.2018.1476740.

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34

Sundaram, S., P. Subhasri, R. Jayaprakasam, and V. N. Vijayakumar. "Thermal and optical characterization of multiple hydrogen bonded liquid crystals derived from mesogenic and non-mesogenic compounds: experimental and theoretical (DFT) studies." Canadian Journal of Physics 98, no. 5 (May 2020): 413–24. http://dx.doi.org/10.1139/cjp-2018-0624.

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A set of new cyclic multiple hydrogen bonded liquid crystals (HBLCs) have been designed and synthesized from citric acid (CA) and 4-dodecyloxybenzoic acid (12OBA). The presence of intermolecular hydrogen bonds (H-bonds) between non-mesogenic and mesogenic compounds has been confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) studies. The hydrogen bonding interactions were explained from natural bond orbital (NBO) analysis using B3LYP/6-311G(d,p) level of theory. Additionally, the Mulliken atomic charges reveal the nature of charge distribution in the HBLC complex. The dynamics of phase transitions and the corresponding stability factor have been evaluated using polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and electrostatic potential (ESP) analysis. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of the CA+12OBA complex is theoretically calculated and experimentally verified. It is found that the variation in the mole ratio in mesogenic with non-mesogenic compound induces the stabilized nematic (N) and smectic X (Sm X) phases. Photocatalytic activity of the CA+12OBA HBLC complex reveals the usage of its optical applications.

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35

Herman, Jakub, Piotr Harmata, Michał Czerwiński, Olga Strzeżysz, Marta Pytlarczyk, Monika Zając, and Przemysław Kula. "Synthesis, Mesomorphism and the Optical Properties of Alkyl-deuterated Nematogenic 4-[(2,6-Difluorophenyl)ethynyl]biphenyls." Materials 14, no. 16 (August 18, 2021): 4653. http://dx.doi.org/10.3390/ma14164653.

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The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.

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36

Veytsman, Boris A. "Theory of nematic phases in solutions of rodlike molecules with hydrogen bonds." Journal of Chemical Physics 103, no. 6 (August 8, 1995): 2237–46. http://dx.doi.org/10.1063/1.469699.

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37

Jber, Nasreen R., Nisreen H. Karam, and Ammar H. Al-Dujaili. "Supramolecular columnar discotic nematic liquid crystal by hydrogen bonding: Synthesis and characterization." Molecular Crystals and Liquid Crystals 675, no. 1 (November 2, 2018): 29–38. http://dx.doi.org/10.1080/15421406.2019.1612158.

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38

Mawer, Peter J., Thomas A. Waigh, Richard Harding, Tom C. B. McLeish, Stephen M. King, Mark Bell, and Neville Boden. "Small-Angle Neutron Scattering from Peptide Nematic Fluids and Hydrogels under Shear." Langmuir 19, no. 12 (June 2003): 4940–49. http://dx.doi.org/10.1021/la0267342.

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Vijayakumar, V. N., and M. L. N. Madhu Mohan. "Dielectric Relaxations in Nematic Phase of Hydrogen Bonded Liquid Crystal Homologous Series." Ferroelectrics 413, no. 1 (January 2011): 156–69. http://dx.doi.org/10.1080/00150193.2011.554142.

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Vijayakumar, V. N., and M. L. N. Madhu Mohan. "Optical modulation in nematic phase of halogen substituted hydrogen bonded liquid crystals." Phase Transitions 85, no. 1-2 (January 2012): 113–30. http://dx.doi.org/10.1080/01411594.2011.594371.

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41

Antonova, K., M. Petrov, N. Kirov, T. Tenev, H. Ratajczak, and J. Baran. "Far-IR spectroscopic investigations of nematic liquid crystals with hydrogen-bonded molecules." Journal of Molecular Structure 325 (September 1994): 189–201. http://dx.doi.org/10.1016/0022-2860(94)80035-9.

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42

Asaba, Kazunori, Akira S. T. Kubota, Hideki F. Tanaka, Atsuko Igarashi, and Shunsuke Kobinata. "Phase Behavior of Nematic-Nonnematic Binary Systems II - The Effect of Hydrogen Bonding -." Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 318, no. 1 (August 1998): 243–52. http://dx.doi.org/10.1080/10587259808045387.

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43

Nandi, Rajib, Varsha Jain, Manisha Devi, Tarang Gupta, and Santanu Kumar Pal. "Hydrogen bond assisted anchoring transitions in nematic liquid crystals at the aqueous interface." Colloids and Surfaces A: Physicochemical and Engineering Aspects 625 (September 2021): 126952. http://dx.doi.org/10.1016/j.colsurfa.2021.126952.

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Lee, Jong Baek, and Byung Won Kang. "Synthesis and Properties of Thermotropic Main-Chain Type Liquid Crystalline Polyurethanes Containing Biphenyl Mesogen." Key Engineering Materials 342-343 (July 2007): 729–32. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.729.

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A new type of thermotropic main-chain liquid crystalline polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 1,4-phenylene diisocyanate, with 4,4′-Bis(8-hydroxyoctoxy)biphenyl (BP8). The structure of the monomer and the corresponding polymers were confirmed using FT-IR and 1H-NMR spectroscopic methods. BP8 exhibited a smectic type mesophase, however, nematic phases were found for all synthesized liquid crystalline polyurethanes except for 1,4-phenylene diisocyanate/BP8 based polyurethane. For example, polyurethane 2,5-TDI/BP8 exhibited monotropic liquid crystallinity in the temperature ranging from 172 to 160 °C on the cooling stage. Properties of these polyurethanes were studied by differential scanning calorimetry (DSC), and optical polarizing microscopy. The FT-IR study indicated that the hydrogen bonding among urethane linkages attributed to the mesomorphism.

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45

LEE, JONG BACK, SANG PILL LEE, and JIN KYUNG LEE. "SYNTHESIS AND CHARACTERIZATION OF NEW THERMOTROPIC LIQUID CRYSTALLINE POLYURETHANES WITH BIPHENYL MOIETY." International Journal of Modern Physics B 20, no. 25n27 (October 30, 2006): 4487–92. http://dx.doi.org/10.1142/s0217979206041562.

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A new series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 1,4-phenylene diisocyanate, with 4,4□-bis(9-hydroxynonoxy)biphenyl (BP9). Structures of the monomer and the corresponding polymers were identified using FT-IR and 1 H NMR spectroscopic methods. BP9 exhibited a smectic type mesophase, however, nematic phase was found for all synthesized liquid crystalline polyurethanes except for 1,4-phenylene diisocyanate/BP9 based polyurethane. Their phase transition temperatures and thermal stability were investigated by differential scanning calorimetry (DSC), optical polarizing microscopy, and X-ray scattering. The infrared study indicated that the hydrogen bonding among urethane linkages attributed to the mesomorphism. Thermal gravimetric analysis (TGA) of synthesized polyurethanes showed that no weight loss of the polymers observed up to 280°C.

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Walker, R., D. Pociecha, J. P. Abberley, A. Martinez-Felipe, D. A. Paterson, E. Forsyth, G. B. Lawrence, et al. "Spontaneous chirality through mixing achiral components: a twist-bend nematic phase driven by hydrogen-bonding between unlike components." Chemical Communications 54, no. 27 (2018): 3383–86. http://dx.doi.org/10.1039/c8cc00525g.

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Arakawa, Yuki, Yukito Sasaki, Kazunobu Igawa, and Hideto Tsuji. "Hydrogen bonding liquid crystalline benzoic acids with alkylthio groups: phase transition behavior and insights into the cybotactic nematic phase." New Journal of Chemistry 41, no. 14 (2017): 6514–22. http://dx.doi.org/10.1039/c7nj00282c.

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Syrbu, S. A., M. S. Fedorov, E. A. Lapykina, and V. V. Novikov. "Dielectric properties of the system: 4-n-pentyloxybenzoic acid– N-(4-n-butyloxybenzylidene)-4᾽-methylaniline." Fine Chemical Technologies 16, no. 2 (May 25, 2021): 138–47. http://dx.doi.org/10.32362/2410-6593-2021-16-2-138-147.

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Objectives. Our aim was to study the dielectric properties of the 4-n-pentyloxybenzoic acid– N-(4-n-butyloxybenzylidene)-4’-methylaniline system and reveal how different concentrations of N-(4-n-butyloxybenzylidene)-4’-methylaniline additives affect the dielectric properties of 4-n-pentyloxybenzoic acid.Methods. System properties were investigated using polarization thermomicroscopy and dielcometry.Results. We found that dielectric anisotropy changes its sign from positive to negative at the transition temperature of the high-temperature nematic subphase to the low-temperature one. The anisotropy of the dielectric constant of N-4-n-butoxybenzylidene-4’-methylaniline has a positive value and increases as to the system approaches the crystalline phase. The crystal structure of the 4-n-pentyloxybenzoic acid contains dimers formed by two independent molecules due to a pair of hydrogen bonds. The crystal structure of N-(4-n-butoxybenzylidene)-4’-methylaniline contains associates formed by orientational interactions of two independent molecules. 4-n-Pentyloxybenzoic acid dimers (270 nm) and associates of N-4-n-butoxybenzylidene-4’- methylaniline (250 nm) proved to have approximately the identical length. Considering the close length values of the structural units of both compounds and the dielectric anisotropy sign, we assume that the N-4-n-butoxybenzylidene-4’-methylaniline associates are incorporated into the supramolecular structure of the 4-n-pentyloxybenzoic acid. The specific electrical conductivity of the compounds under study lies between 10−7 and 10−12 S∙cm−1. The relationship between the specific electrical conductivity anisotropy and the system composition in the nematic phase at the identical reduced temperature, obtained between 100 and 1000 Hz is symbatic. However, the electrical conductivity anisotropy values of the system obtained at 1000 Hz are lower compared to those obtained at 100 Hz. At N-(4-n-butoxybenzylidene)-4’-methylaniline concentrations between 30 and 60 mol %, the electrical conductivity anisotropy values are higher than those of the individual component.Conclusions. A change in the sign of the dielectric constant anisotropy of the 4-n-pentyloxybenzoic acid during nematic subphase transitions was established. We showed that the system has the highest dielectric constant anisotropy value when components have an equal number of moles. Highest electrical conductivity anisotropy values are observed when the concentration of the N-4-n-butoxybenzylidene-4᾽-methylaniline system lies between 30 and 60 mol %.

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Kim, Jongyoon, Jahyeon Koo, Jimin Park, Kwang-Un Jeong, and Ji-Hoon Lee. "Enhancement of flexoelastic ratio of nematic liquid crystal doped with hydrogen-bonded bimesogen molecules." Journal of Molecular Liquids 277 (March 2019): 541–45. http://dx.doi.org/10.1016/j.molliq.2018.12.150.

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Missaoui, Tayssir, Ines Ben Amor, Taoufik Soltani, Hafedh Ben Ouada, Erwann Jeanneau, and Yves Chevalier. "Dielectric and electro-optic properties of cybotactic nematic phase in hydrogen-bonded liquid crystals." Journal of Molecular Liquids 304 (April 2020): 112726. http://dx.doi.org/10.1016/j.molliq.2020.112726.

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