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Artículos de revistas sobre el tema "Mesogenic materials"

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Autor: Grafiati

Publicado: 18 de mayo de 2024

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1

Paul, Saurav, Bimal Bhushan Chakraborty, Kuheli Deb y Sudip Choudhury. "Synthesis of mesogen-nanoparticle composites by doping 4-decyloxybenzoic acid with substrate-functionalized ZnO nanoparticle". Communications in Science and Technology 8, n.º 1 (8 de julio de 2023): 38–42. http://dx.doi.org/10.21924/cst.8.1.2023.1125.

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Nanomaterials and Mesogenic materials are two important pillars of today’s science and technology, in the fields of both material and biological applications. Mesogens or liquid crystals (LC) are self-aggregated anisotropic fluids with long range order, and the nature of self-aggregation largely controls their physical and material properties. Doping of nanomaterials over liquid crystalline matrix can provide valuable tools for development of materials with new or improved properties. In the present work 4-decyloxybenzoic acid is taken as the mesogenic matrix. It is observed that, composite prepared by doping of 4-decyloxybenzoic acid mesogen matrix by ZnO nanoparticle pre-functionalized with the same mesogen, caused a marked alteration in the mesogenic behavior. With 3% doping of matrix pre-functionalized ZnO NP on 4- decyloxy benzoic acid, we could achieve a shift of about 31ºC in the N-Iso transition temperature and, a decrease of >10ºC for the onset of liquid crystallinity by this method without quenching any of the mesophases exhibited by the pure mesogen. The synthesized materials have been characterized by variable temperature Polarised optical microscopy (POM), DSC, FTIR, XRD, EDX, and TEM This process may be considered for preparation other nanoparticle-mesogen composites as well. It was observed that, the effect of doping on the transition temperature and enthalpy of 4-Decyloxybenzoic Acid can be significantly enhanced by pre-functionalizing the dopant (ZnO NP) with the substrate molecules and then mixing this substrate functionalized ZnO nanoparticle with the bulk substrate.

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2

Gorbachev, Stanislav A. y yacheslav V. Zuev. "Synthesis and Mesomorphic Properties of Biphenyl Derivatives with Central Unit Based on 1,6-Hexamethylene Diisocyanate Oligomers". Liquid Crystals and their Application 22, n.º 4 (22 de diciembre de 2022): 27–36. http://dx.doi.org/10.18083/lcappl.2022.4.27.

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A number of compounds with biphenyl as a mesogenic fragment and a structure simulating LC dimers, polymers with mesogenic side chain groups and a star-shaped structure have been synthesized. An approach for the synthesis of such compounds under mild conditions and without a complex purification procedure with a quantitative yield, has been developed. The approach is the implementation of “click chemistry” methods for the synthesis of LC compounds. It has been shown that the LC state is observed only if there are three biphenyls in one molecule, i.e., the compounds appear to be similar to polyesters with biphenyl as a mesogenic moiety. The determining factor in the formation of the LC state and particularly smectic mesomorphism of compounds with such a potentially “weak” mesogen as biphenyl is the formation of intermolecular hydrogen bonds.

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3

Goodby, J. W. "Mesogenic molecular crystalline materials". Current Opinion in Solid State and Materials Science 4, n.º 4 (agosto de 1999): 361–68. http://dx.doi.org/10.1016/s1359-0286(99)00035-2.

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4

Dolden, J. G. y P. T. Alder. "The Mesogenic Index: An Empirical Method for Predicting Polymeric Liquid Crystallinity". High Performance Polymers 10, n.º 3 (septiembre de 1998): 249–72. http://dx.doi.org/10.1088/0954-0083/10/3/004.

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An empirical method for predicting the chemical compositions of random or partially ordered copolymers that exhibit mesophases was devised by the authors in 1989, while working on liquid crystal copolymer synthesis for BP Chemicals. A brief description of the method and its application to the chemical synthesis of amorphous thermotropic polyamides was given by the authors in a previous paper. Thermotropic polyimides were also synthesized by the authors as a result of the use of the predictive method. Subsequently, the method has been updated and applied to polycarbonates and polyimides. The new approach has been termed ‘the mesogenic index’ (MI) and has successfully been applied to 23 copolymer systems in which the critical compositions for mesophase formation have been established by means of varying constituent monomer concentrations. It is also consistent in predicting liquid crystalline behaviour in several hundred main-chain polymer systems containing amide, ester, carbonate, ether and urethane groups. It is inherent in the MI system that the mesogenic length is defined in terms of the number of monomer units for a given polymer class. From published work in the literature, it was first established that ester and amide groups need at least two and three aromatic rings in the mesogen respectively. Using these values to define mesogen length in polyester and polyamide copolymers, the condition MI > 10 has been determined for mesophase formation. This rule has been applied to other linking groups, such as carbonate or imide, with the surprising result that the corresponding mesogen lengths for these condensation polymers are simple numbers. Moreover, the rule has been applied successfully to mixed systems, by simply averaging the contributions of the different groups to the mesogen length in strictly molar proportions. The mesogenic index is based upon summing functional group contributions towards rigidity and/or resonance stabilization of the mesogen. To the best of our knowledge, this is the first simple method to be published that successfully correlates chemical composition with mesophase formation.

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5

Malthête, Jacques. "Mesogenic calixarenes". Advanced Materials 6, n.º 4 (abril de 1994): 315. http://dx.doi.org/10.1002/adma.19940060414.

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6

Guo, Fei y Robert Hurt. "Supramolecular Synthesis of Graphenic Mesogenic Materials". Macromolecular Chemistry and Physics 213, n.º 10-11 (27 de marzo de 2012): 1164–74. http://dx.doi.org/10.1002/macp.201100600.

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7

Hakemi, H. "The effect of a compatible liquid crystal polymer on homogeneous reinforcement of mesogenic and nonmesogenic rigid-rod monomers". Material Science & Engineering International Journal 6, n.º 1 (31 de enero de 2022): 1–4. http://dx.doi.org/10.15406/mseij.2022.06.00172.

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Discrete amount of main-chain Liquid Crystal Polymers (LCP) could mechanically reinforce the mesophase of rigid-rod monomers to form a supramolecular homogeneous composite for Liquid Crystal Display (LCD) materials. Moreover, a homogeneously dispersed LCP may induce an enantiotropic transition in monotropic or non-mesogenic rigid-rod compounds. In this work, we studied the blends of a flexible main-chain nematic LCP with an enantiotropic nematic, a monotropic nematic, and two non-mesogenic rigid-rod compounds as model systems. The results indicate that homogenous reinforcement of thermotropic LCP in these monomers is a valid concept and could lead to improvement of mesogenic stability, orienational and mechanical properties of rigid-rod materials for various applications.

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8

Rabie, Feras, Lenka Poláková, Sebastian Fallas, Zdenka Sedlakova, Eva Marand y Stephen M. Martin. "Temperature-Dependent Gas Transport Behavior in Cross-Linked Liquid Crystalline Polyacrylate Membranes". Membranes 9, n.º 8 (20 de agosto de 2019): 104. http://dx.doi.org/10.3390/membranes9080104.

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Stable, cross-linked, liquid crystalline polymer (LCP) films for membrane separation applications have been fabricated from the mesogenic monomer 11-(4-cyanobiphenyl-4′-yloxy) undecyl methacrylate (CNBPh), non-mesogenic monomer 2-ethylhexyl acrylate (2-EHA), and cross-linker ethylene glycol dimethacrylate (EGDMA) using an in-situ free radical polymerization technique with UV initiation. The phase behavior of the LCP membranes was characterized using differential scanning calorimetry (DSC) and X-ray scattering, and indicated the formation of a nematic liquid crystalline (LC) phase above the glass transition temperature. The single gas transport behavior of CO2, CH4, propane, and propylene in the cross-linked LCP membranes was investigated for a range of temperatures in the LC mesophase and the isotropic phase. Solubility of the gases was dependent not only on the condensability in the LC mesophase, but also on favorable molecular interactions of penetrant gas molecules exhibiting a charge separation, such as CO2 and propylene, with the ordered polar mesogenic side chains of the LCP. Selectivities for various gas pairs generally decreased with increasing temperature and were discontinuous across the nematic–sotropic transition. Sorption behavior of CO2 and propylene exhibited a significant change due to a decrease in favorable intermolecular interactions in the disordered isotropic phase. Higher cross-link densities in the membrane generally led to decreased selectivity at low temperatures when the main chain motion was limited by the lack of mesogen mobility in the ordered nematic phase. However, at higher temperatures, increasing the cross-link density increased selectivity as the cross-links acted to limit chain mobility. Mixed gas permeation measurements for propylene and propane showed close agreement with the results of the single gas permeation experiments.

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9

Lu, Yao-Chih, Yu-Tsz Hsu, Tsung-Yen Yang, I.-Chun Liou, Sheng-Wei Wang, Po-Chia Huang, Jey-Jau Lee, Long-Li Lai y Hsiu-Fu Hsu. "Converting non-Mesogenic to Mesogenic Stacking of Amino-s-Triazine-Based Dendrons with p-CN Phenyl Unit by Eliminating Peripheral Dipole". Nanomaterials 12, n.º 2 (6 de enero de 2022): 185. http://dx.doi.org/10.3390/nano12020185.

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Three new amino-s-triazine-based dendrons, 1a, 1b, and 1c, containing an aryl-CN moiety in the dendritic skeleton were prepared in 72–81% yields (1a: R1 = − N(n-C8H17)2, R2 = n-OC8H17, 1b: R1 = R2 = − N(n-C8H17)2, 1c: R1 = − N(n-C8H17)2, R2 = − N(n-C4H9)2). Dendrons 1a with N(n-C8H17)2 and n-OC8H17 peripheral substituents, surprisingly, did not show any mesogenic phase during the thermal process. However, non-mesogenic 1a can be converted to mesogenic 1b or 1c by eliminating the peripheral dipole arising from the alkoxy substituent; dendron 1b only comprising the same N(n-C8H17)2 peripheral groups showed a ~25 °C mesogenic range on heating and ~108 °C mesogenic range on cooling. In contrast, dendron 1c possessing different N(n-CmH2m+1)2 (m = 8 versus m = 4) peripheral units, having similar stacking as 1b, exhibited a columnar phase on thermal treatment, but its mesogenic range (~9 and ~66 °C on heating and cooling, respectively) was much narrower than that of 1b, attributed to 1c’s less flexible alkyl chains in the peripheral part of dendron. Dendron 1a with the alkoxy substituent in the peripheral skeleton, creating additional dipole correspondingly, thus, leads to the dendritic molecules having a non-mesogenic stacking. Without the peripheral dipole for intermolecular side-by-side interaction, dendrons 1b and 1c exhibit a columnar phase on thermal treatment because of the vibration from the peripheral alkyl chain.

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10

Ono, H., T. Kawamura, N. M. Frias, K. Kitamura, N. Kawatsuki y H. Norisada. "Photorefractive Mesogenic Composites". Advanced Materials 12, n.º 2 (enero de 2000): 143–46. http://dx.doi.org/10.1002/(sici)1521-4095(200001)12:2<143::aid-adma143>3.0.co;2-9.

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11

Nagase, Yu, Yuriko Takamura y Eiichi Akiyama. "Side chain liquid crystalline polymers containing siloxane spacer: 7. Syntheses and properties of polyimides and polyamides containing a mesogenic side chain connected with a disiloxane linkage". High Performance Polymers 7, n.º 3 (junio de 1995): 255–66. http://dx.doi.org/10.1088/0954-0083/7/3/002.

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Preparations of polyimides and polyamides containing a mesogenic group in the side chain connected with a siloxane bond in the spacer component were carried out. A 3,5-diaminobenzyloxy-type monomer having a mesogen consisting of a p'-substituted biphenyl benzoate group was prepared by means of hydrosilylation of 1-[3-43,5-dinitrobenzyloxy)propyl]-1,1,3,3-tetramethyldisiloxane with a mesogenic allyloxy compound, followed by catalytic reduction of the two nitro groups. The polyimides were synthesized by polycondensation of the diamine monomers with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), followed by chemical imidization. The polyamides were also synthesized by polycondensation of the diamine monomers with dicarboxylic dichloride compounds, i.e., terephthaloyl dichloride, oxalyl dichloride, malonyl dichlonride, succinyl dichloride, glutaryI dichloride, adipoyl dichloride, pimeloyI dichloride and azelaoyl dichloride. The structural effects on the thermal properties of the polymers were investigated. The obtained polyamides having an aliphatic group in the main chain exhibited an enantiotropic smectic mesophase at around 100-150C, while no mesophase was observed for the polyimides and a polyamide having an aromatic backbone.

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12

Romiszewski, Jerzy, Zita Puterová-Tokarová, Jozef Mieczkowski y Ewa Gorecka. "Optical properties of thiophene-containing liquid crystalline and hybrid liquid crystalline materials". New J. Chem. 38, n.º 7 (2014): 2927–34. http://dx.doi.org/10.1039/c4nj00298a.

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13

Bubnov, Alexej, Martin Cigl, Deyvid Penkov, Marek Otruba, Damian Pociecha, Hsiu-Hui Chen y Věra Hamplová. "Design and Self-Assembling Behaviour of Calamitic Reactive Mesogens with Lateral Methyl and Methoxy Substituents and Vinyl Terminal Group". Polymers 13, n.º 13 (30 de junio de 2021): 2156. http://dx.doi.org/10.3390/polym13132156.

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Smart self-organising systems attract considerable attention in the scientific community. In order to control and stabilise the liquid crystalline behaviour, and hence the self-organisation, the polymerisation process can be effectively used. Mesogenic units incorporated into the backbones as functional side chains of weakly cross-linked macromolecules can become orientationally ordered. Several new calamitic reactive mesogens possessing the vinyl terminal group with varying flexible chain lengths and with/without lateral substitution by the methyl (methoxy) groups have been designed and studied. Depending on the molecular structure, namely, the type and position of the lateral substituents, the resulting materials form the nematic, the orthogonal SmA and the tilted SmC phases in a reasonably broad temperature range, and the structure of the mesophases was confirmed by X-ray diffraction experiments. The main objective of this work is to contribute to better understanding of the molecular structure–mesomorphic property relationship for new functional reactive mesogens, aiming at further design of smart self-assembling macromolecular materials for novel sensor systems.

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14

Sannaninganavar, F. M., N. H. Ayachit y D. K. Deshpande. "Dielectric studies on some mesogenic, non-mesogenic and organic molecules". Physics and Chemistry of Liquids 47, n.º 3 (junio de 2009): 259–66. http://dx.doi.org/10.1080/00319100701198560.

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15

Lu, Yao-Chih, Hsiu-Fu Hsu y Long-Li Lai. "Unconventional Approaches to Prepare Triazine-Based Liquid Crystal Dendrimers". Nanomaterials 11, n.º 8 (19 de agosto de 2021): 2112. http://dx.doi.org/10.3390/nano11082112.

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Most triazine-based liquid crystalline (LC) dendrimers reported thus far are the main-chain LC macromolecules with long flexible chains at their periphery and attached to internal rigid or semi-rigid frameworks. Their formation of mesogenic phases often depends on the intermolecular face-to-face π–π interactions between dendritic molecules, which are unusual. Their mesogenic phases can also be formed by incorporation of mesogenic units to the dendritic skeletons through long flexible chains, as most side-chain LC dendrimers, in which the peripheral mesogenic units generally play the important roles. For main-chain triazine-based dendrimers, their morphology is maintained by restricted freedom of rigid or semi-rigid connecting units, and their formations of LC phases are therefore not straightforward to be controlled. In this review, we thus describe modulating of the intermolecular face-to-face π–π interactions between the triazine-based dendritic molecules, with the aim of forming LC phases through molecular design.

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16

H, Hakemi. "Metallomesogens as potential materials for improvement of electro-optical properties of commercial liquid crystals". Material Science & Engineering International Journal 7, n.º 2 (19 de junio de 2023): 108–11. http://dx.doi.org/10.15406/mseij.2023.07.00213.

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We present a new approach to utilize the eutectic metallomesogen (MOM) mixtures to improve the electro-optical properties of commercial nematic liquid crystal (NLC) materials. Accordingly, we studied the phase diagrams of rod-like MOM models structures, including alkyl/alkoxy-azobenzene with Pd complex and salicylal-diaminates with Cu, Ni and Pd complexes. These phase diagrams we utilized the eutectic MOM mixtures and mixed them with few commercial NLC hosts. The results showed a complete mesogenic miscibility and wide mesogenic range. Although the studied MOM model materials are not the optimum structures and we did not study the electro-optical properties of MOM-NLC mixtures, the present results indicate the potential application of MOMs to improve the performance of commercial NLC, which require further future studies.

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17

Kong, Xiangfei, Hongkang Gong, Peng Liu, Wei Yao, Zheng Liu, Guixia Wang, Shufen Zhang y Zhiqun He. "Synthesis and investigation on optoelectronic properties of mesogenic triphenylene–perylene dyads linked by ethynylphenyl bridges". New Journal of Chemistry 42, n.º 5 (2018): 3211–21. http://dx.doi.org/10.1039/c7nj04328g.

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18

Soto Bustamante, E. A., R. Werner, T. Weyrauch, P. A. Navarrete-Encina y W. Haase. "Antiferroelectricity in achiral mesogenic mixtures of organic materials". Chemical Physics Letters 322, n.º 1-2 (mayo de 2000): 45–50. http://dx.doi.org/10.1016/s0009-2614(00)00403-6.

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19

Patel, H. N. y A. K. Prajapati. "Mesogenic naphthyl derivatives". Molecular Crystals and Liquid Crystals 643, n.º 1 (22 de enero de 2017): 106–15. http://dx.doi.org/10.1080/15421406.2016.1262712.

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20

Vasan, S. T., F. M. Sannaninganavar, N. H. Ayachit y D. K. Deshpande. "Dielectric behavior of some mesogenic-, non-mesogenic- and organic molecules". Journal of Molecular Liquids 135, n.º 1-3 (julio de 2007): 38–41. http://dx.doi.org/10.1016/j.molliq.2006.10.001.

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21

Ghode, Archana, Uma Shivkumar y B. K. Sadashiva. "Mesogenic β-diketones and metallonematogens". Bulletin of Materials Science 17, n.º 3 (junio de 1994): 283–97. http://dx.doi.org/10.1007/bf02745179.

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22

Ghanadzadeh, A. "Dielectric investigations and molecular association in non-mesogenic and mesogenic solutions". Journal of Molecular Liquids 102, n.º 1-3 (enero de 2003): 365–77. http://dx.doi.org/10.1016/s0167-7322(02)00161-7.

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23

Shanks, Robert A. y Daniel Staszczyk. "Thermal and Optical Characterization of Polymer-Dispersed Liquid Crystals". International Journal of Polymer Science 2012 (2012): 1–13. http://dx.doi.org/10.1155/2012/767581.

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Liquid crystals are compounds that display order in the liquid state above the melting temperature and below the mesogenic isotropic temperature. Polymer-dispersed liquid crystals (PDLCs) are composite materials in which liquid crystalline material is dispersed within a polymer matrix to form micron-sized droplets. The aim was to prepare several cholesteryl esters or alkoxybenzoic acid PDLCs and characterise thermal and optical properties. Differential scanning calorimetry and polarized optical microscopy were employed. The matrix polymer was a one-component UV-curable epoxy-acrylate resin. PDLCs were formed through entropy controlled phase separation resulting from UV-initiated crosslinking. The liquid crystals, both as mesogenic moieties and as dispersed droplets, exhibited various textures according to their molecular order and orientation. These textures formed in constrained regions separated by phase boundaries that occurred at temperatures characteristic of each liquid crystal used. The PDLC phase transitions occurred at temperatures lower than those exhibited by the mesogenic components in the neat state.

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24

Alonso, Pablo J., Jesús I. Martínez, Luis Oriol, Milagros Piñol y José Luis Serrano. "Paramagnetic metal-containing mesogenic polyazomethines". Advanced Materials 6, n.º 9 (septiembre de 1994): 663–67. http://dx.doi.org/10.1002/adma.19940060909.

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25

Orlandi, Silvia, Luca Muccioli, Matteo Ricci y Claudio Zannoni. "Self assembled fullerene walls in di-mesogenic-C60 materials". Soft Matter 5, n.º 22 (2009): 4484. http://dx.doi.org/10.1039/b911336c.

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26

Haßheider, T., S. A. Benning, M. W. Lauhof, H. S. Kitzerow, H. Bock, M. D. Watson y K. Müllen. "ORGANIC HETEROJUNCTION PHOTOVOLTAIC CELLS MADE OF DISCOTIC, MESOGENIC MATERIALS". Molecular Crystals and Liquid Crystals 413, n.º 1 (enero de 2004): 461–72. http://dx.doi.org/10.1080/15421400490439103.

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27

Govindaiah, T. N., Nagappa, P. M. Sathyanarayana, J. Mahadeva y H. R. Sreepad. "Induced Chiral Smectic Phase in Mixtures of Mesogenic and Non-Mesogenic Compounds". Molecular Crystals and Liquid Crystals 548, n.º 1 (7 de octubre de 2011): 55–60. http://dx.doi.org/10.1080/15421406.2011.590358.

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28

Itahara, Toshio, Akihiro Nishino, Shushi Furukawa y Kaoru Kubota. "Mesogenic behaviour ofp-nitrophenyl group linked with biphenyl mesogens via flexible spacers". Liquid Crystals 40, n.º 9 (septiembre de 2013): 1167–73. http://dx.doi.org/10.1080/02678292.2013.817619.

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29

Erdoğan, Buket S., Devrim Atilla, Ayşe G. Gürek y Vefa Ahsen. "Liquid crystalline alkylthia-substituted novel phthalocyanines: synthesis and characterization". Journal of Porphyrins and Phthalocyanines 18, n.º 01n02 (enero de 2014): 139–48. http://dx.doi.org/10.1142/s1088424613501149.

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Methylene-bridged tetra- and octa-alkylthia substituted metal free- and Ni ( II ) phthalocyanines were synthesized from the corresponding phthalonitrile derivatives in the presence of the anhydrous metal salt ( NiCl 2) or a strong organic base. The new compounds were fully characterized by elemental analyses, UV-vis, IR, NMR and mass spectra. The mesogenic properties of these materials were studied by differential scanning calorimetry, optical microscopy and X-ray diffraction investigations. X-ray diffraction patterns of the mesophase confirmed that the tetra- and the octa-substituted compounds formed hexagonal columnar mesophases (Colh). The mesogenic properties of these compounds were compared to that of their octa alkythia substituted phthalocyanine derivatives in the literature.

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Alder, P., J. G. Dolden y P. Smith. "The synthesis and characterization of liquid crystalline oligoimides and polyimides". High Performance Polymers 7, n.º 4 (agosto de 1995): 421–31. http://dx.doi.org/10.1088/0954-0083/7/4/004.

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There are few examples of thermotropic polyimides reported in the literature. In the present article the authors report the synthesis and characterization of some novel oligoand poly-imides which exhibit mesogenic behaviour. The solution method of Yamazaki et al (Yamazaki N, Higashi F and Kawasaki J 1974 J. Polym. Sci., Polym. Chem. Ed. 12 2149) for the preparation of polyamides was successfully applied to the formation of imide compounds and oligomers. Liquid crystal phases were characterized by optical polarizing microscopy and by differential scanning calorimetry. Two anhydrides were employed which were considered to be suitable building blocks for preparing potentially mesogenic polyimides, namely biphenyl tetracarboxytic dianhydride and pyromellitic dianhydride. Low-molar-mass materials were first synthesized with monoanhydride units to endcap the chains. using nadic and maleic anhydrides. Nematic phases Awere observed in several nadic diimide compounds containing multicyclic cores and in some low-molar-mass diimides and polyimides which contained a biphenylene unit in conjunction with at least one other unsaturated ring When the nadlmldes were heated above 220 C cross-linking and decomposition occurred with loss of mesogenic properties. A fusible polyimide was synthesized containing a flexible chain which exhibited thermotropic behaviour below its decomposition temperature.

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31

Plate', N. A. y R. V. Talroze. "Self-assembling with formation of mesogenic polymer structures in non-mesogenic species". Macromolecular Symposia 106, n.º 1 (abril de 1996): 425–27. http://dx.doi.org/10.1002/masy.19961060141.

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32

Lee, Cheng-Hua, Chun-Chi Huang, Chia-Ying Li, Long-Li Lai, Jey-Jau Lee y Hsiu-Fu Hsu. "Both increasing the Iso-to-Col transition and lowering the solidifying temperatures of a triazine-based dendrimer by introducing CN polar groups in the dendritic core". Journal of Materials Chemistry C 7, n.º 45 (2019): 14232–38. http://dx.doi.org/10.1039/c9tc04004h.

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33

Romanova, Kseniya A. y Yuriy G. Galyametdinov. "Luminescence Efficiency of Mesogenic Europium(III) Complexes and their Composites with Polymers According to Quantum-Chemical Simulation". Liquid Crystals and their Application 22, n.º 4 (22 de diciembre de 2022): 6–15. http://dx.doi.org/10.18083/lcappl.2022.4.6.

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The results of quantum-chemical simulation of the molecular structure and excited states of some mesogenic europium(III) (Eu(III)) complexes and liquid-crystalline (LC) (co)polymers are provided. These objects represent the components of currently relevant composites with a hybrid structure, unique optical and magnetic properties for optoelectronic devices. The relationships between the geometric parameters, LC properties, and luminescence efficiency of the mesogenic Eu(III) complexes with &beta-diketones and Lewis bases have been studied. The calculated values of the lowest singlet and triplet excited states were used to determine the channels of inter- and intramolecular energy transfer between the excited levels of polymers and Eu(III) complexes. The data of quantum-chemical simulation allowed to select components for the subsequent synthesis and creation of effective optoelectronic materials.

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34

Skopalová, Helena, Petr Špaček, Václav Kozmík, Jiří Svoboda, Vladimíra Novotná, Damian Pociecha y Michal Kohout. "The Role of Substitution in the Apex Position of the Bent-Core on Mesomorphic Properties of New Series of Liquid Crystalline Materials". Crystals 10, n.º 9 (21 de agosto de 2020): 735. http://dx.doi.org/10.3390/cryst10090735.

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We present the synthesis and mesomorphic properties of the new series of bent-core liquid crystals based on 3-hydroxybenzoic acid bearing a lateral substituent in the apex position. Four different substituents of various sizes and electronic properties have been used. We have found that only compounds substituted with fluorine are mesogenic and exhibit one mesophase, whose type differs when prolonging the terminal alkyl chain. For homologues with shorter alkyl chains (octyl, decyl), a columnar B1-type of a mesophase was observed, while materials with longer terminal chains (dodecyl, tetradecyl) exhibited a switchable lamellar SmCAPA phase. Calorimetric measurements, texture observations under a polarizing microscope were performed and electro-optical properties studied. Additionally, dielectric measurements were realized to characterize the molecular dynamics in the SmCAPA phase. All mesogenic compounds were further studied by X-ray measurements to confirm phase identification and obtain more information about their structural parameters.

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35

Romanova, Kseniya A. y Yuriy G. Galyametdinov. "Simulation of Energy Transfer Processes in Mesogenic Binuclear Complexes of Lanthanides(III)". Liquid Crystals and their Application 24, n.º 1 (28 de marzo de 2024): 22–35. http://dx.doi.org/10.18083/lcappl.2024.1.22.

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Quantum-chemical simulation of the molecular structure and excited state energies of some mesogenic binuclear complexes of lanthanides(III) with substituted β-diketones and Lewis bases have been performed. Correlations between geometric parameters, structural features of the complexes' coordination polyhedra, potential liquid-crystalline properties, and luminescence efficiency were analyzed. According to the calculated values of the lowest singlet and triplet excited states of the ligands, energy level diagrams were constructed and the main channels of intramolecular energy transfer between the excited levels of the ligands and lanthanide(III) ions were defined. The process of interionic energy transfer was elucidated and the ligand environment for the creation of mesogenic binuclear lanthanide(III) complexes with intense luminescence was proposed.

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36

Furue, Hirokazu, Ryosuke Hara y Yusuke Nagata. "Blue Phase in Photocurable Mesogenic Monomers for Nano-structured Materials". Molecular Crystals and Liquid Crystals 608, n.º 1 (11 de febrero de 2015): 239–45. http://dx.doi.org/10.1080/15421406.2014.989041.

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37

Ono, Hiroshi y Nobuhiro Kawatsuki. "Strong beam coupling in mesogenic materials with photorefractive Bragg gratings". Optics Letters 24, n.º 3 (1 de febrero de 1999): 130. http://dx.doi.org/10.1364/ol.24.000130.

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38

Mohana, K. y S. Umadevi. "Side-chain polysiloxane liquid crystalline elastomers from non-mesogenic components". New Journal of Chemistry 43, n.º 40 (2019): 15968–78. http://dx.doi.org/10.1039/c9nj03482j.

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39

Hussain, Zakir, Henning Hopf y S. Holger Eichhorn. "Perhydroazulene-based liquid-crystalline materials with smectic phases". Beilstein Journal of Organic Chemistry 8 (16 de marzo de 2012): 403–10. http://dx.doi.org/10.3762/bjoc.8.44.

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New liquid-crystalline materials with a perhydroazulene core were synthesized and the stereochemistry of these compounds was investigated. The mesomorphic properties of the new LC compounds were investigated by differential scanning colorimetry, polarizing optical microscopy and X-ray diffraction. We report here on the LC properties of nonchiral materials, which predominantly exhibit smectic phases and display nematic phases only within narrow temperature ranges. The dependence of the mesogenic behavior of the new materials on the stereochemistry of the core system was also investigated. All newly synthesized compounds were fully characterized by the usual spectroscopic and analytical methods.

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40

Pozhidaev, E. P., V. V. Vashchenko, V. V. Mikhailenko, A. I. Krivoshey, V. A. Barbashov, L. Shi, A. K. Srivastava, V. G. Chigrinov y H. S. Kwok. "Ultrashort helix pitch antiferroelectric liquid crystals based on chiral esters of terphenyldicarboxylic acid". Journal of Materials Chemistry C 4, n.º 43 (2016): 10339–46. http://dx.doi.org/10.1039/c6tc04087j.

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Antiferroelectric liquid crystals (AFLCs) with a nanoscale helix pitch (<100 nm) were revealed in a composition containing achiral smectic-C biphenylpyrimidines and two non-mesogenic chiral dopants.

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41

Girdziunaite, Dalia, Carsten Tschierske, Eva Novotna, Horst Kresse y Annemarie Hetzheim. "New mesogenic 1,3,4-oxadiazole derivatives". Liquid Crystals 10, n.º 3 (septiembre de 1991): 397–407. http://dx.doi.org/10.1080/02678299108026286.

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42

Belloni, Maura, M. Manickam, Zehn-He Wang y Jon A. Preece. "TOWARD BORONATE ESTER MESOGENIC STRUCTURES". Molecular Crystals and Liquid Crystals 399, n.º 1 (1 de enero de 2003): 93–114. http://dx.doi.org/10.1080/15421400390223158.

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43

Tandel, R. C. y R. A. Vora. "Mesogenic amido ester with cholesteryl moiety". Phase Transitions 81, n.º 5 (mayo de 2008): 421–29. http://dx.doi.org/10.1080/01411590701785512.

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44

Katranchev, Boyko y Minko Petrov. "Phase transitions in nanocomposites of hydrogen-bonded dimeric liquid crystals with mesogenic and non-mesogenic components". Phase Transitions 89, n.º 2 (11 de septiembre de 2015): 115–32. http://dx.doi.org/10.1080/01411594.2015.1075242.

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45

Wang, Qing, Chang-an Yang, Helou Xie, Xingzhu Wang y Hailiang Zhang. "Effect of mesogenic density on liquid-crystalline behaviours of polymethacrylates bearing azobenzene mesogen". Liquid Crystals 37, n.º 4 (22 de abril de 2010): 435–43. http://dx.doi.org/10.1080/02678291003642578.

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46

Pecyna, Jacek, Aleksandra Jankowiak, Damian Pociecha y Piotr Kaszyński. "o-Carborane derivatives for probing molecular polarity effects on liquid crystal phase stability and dielectric behavior". Journal of Materials Chemistry C 3, n.º 43 (2015): 11412–22. http://dx.doi.org/10.1039/c5tc02046h.

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A series of mesogenic derivatives ofo-carborane was synthesized, their properties were analyzed by thermal, optical and XRD methods, and results were compared with those of isostructuralp-carborane and benzene analogues.

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47

Chen, Si, Long-Cheng Gao, Xiao-Dong Zhao, Xiao-Fang Chen, Xing-He Fan, Pei-Ying Xie y Qi-Feng Zhou. "Synthesis and Properties of Mesogen-Jacketed Liquid Crystalline Polymers with Asymmetry Mesogenic Core". Macromolecules 40, n.º 16 (agosto de 2007): 5718–25. http://dx.doi.org/10.1021/ma0703554.

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48

Kawano, Shin-ichiro, Kazutaka Narita, Yuka Ikemoto, Ako Sasaki y Kentaro Tanaka. "Mesogenic discrete metallofoldamer for columnar liquid crystal". Chemical Communications 58, n.º 20 (2022): 3274–77. http://dx.doi.org/10.1039/d2cc00310d.

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49

GONIN, D., B. GUICHARD, M. C. J. LARGE, T. DANTAS DE MORAIS, C. NOËL y F. KAJZAR. "SIDE CHAIN LIQUID CRYSTAL POLYMERS FOR QUADRATIC NONLINEAR OPTICS". Journal of Nonlinear Optical Physics & Materials 05, n.º 04 (octubre de 1996): 735–55. http://dx.doi.org/10.1142/s0218863596000520.

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In this paper we consider the behavior of a number of side chain liquid crystal polymers having the same mesogenic group and relate their liquid crystalline behavior to their polarization and nonlinear optical properties. We show that the liquid crystallinity of the materials results in an enhancement of the polar order over that of isotropic materials, in qualitative agreement with molecular statistical models.

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50

Henrissat, B., G. K. Hamer, M. G. Taylor y R. H. Marchessault. "Characterization of some mesogenic alkyl 1-thioglycosides". Canadian Journal of Chemistry 80, n.º 8 (1 de agosto de 2002): 1162–65. http://dx.doi.org/10.1139/v02-157.

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A series of dodecyl 1-thio-β-D-glycosides has been synthesized and characterized (DSC, NMR, CP MAS, X-ray diffraction) as possible new marking materials with liquid-crystalline properties. These compounds undergo solid to liquid crystal phase transitions at various temperatures, which depend on the nature of the carbohydrate part of the structure. Their liquid-crystalline phases show extreme shear thinning behaviour.Key words: liquid crystal, powder X-ray diffraction, phase transition, thioglycoside, solid-state NMR, marking material

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