Distinctive dielectric properties of nematic liquid crystal dimers

References

• Goodby JW, Collings PJ, Kato T, et al., editors. Handbook of liquid crystals. Nematic and chiral nematic liquid crystals. Vol. 3. Weinheim: Wiley-VCH Verlag; 2014.
   Google Scholar
• Goodby JW, Collings PJ, Kato T, et al., editors. Handbook of liquid crystals. Smectic and columnar liquid crystals. Vol. 4. Weinheim: Wiley-VCH Verlag; 2014.
   Google Scholar
• Chandrasekhar S. Discotic liquid crystals. A brief review. Liq Cryst. 1993;14:3–14. doi:10.1080/02678299308027301.
   Web of Science ®Google Scholar
• Reddy RA, Tschierske C. Bent-core liquid crystals: polar order, superstructural chirality and spontaneous desymmetrisation in soft matter systems. J Mater Chem. 2006;16:907–961. doi:10.1039/B504400F.
   Web of Science ®Google Scholar
• Takezoe H, Takanishi Y. Bent-core liquid crystals: their mysterious and attractive world. Jpn J Appl Phys. 2006;45:597–625. doi:10.1143/JJAP.45.597.
   Web of Science ®Google Scholar
• Boden N, Bushby RJ, Cammidge AN, et al. The creation of long-lasting glassy columnar discotic liquid crystals using “dimeric” discogens. J Mater Chem. 1999;9:1391–1402. doi:10.1039/a810045d.
   Web of Science ®Google Scholar
• Diez S, Dunmur DA, de la Fuente MR, et al. Dielectric studies of a laterally-linked siloxane ester dimer. Liq Cryst. 2003;30:1021–1030. doi:10.1080/0267829031000152969.
   Web of Science ®Google Scholar
• Lagerwall JPF, Giesselmann F, Wand MD, et al. A chameleon chiral polar liquid crystal: rod-shaped when nematic, bent-shaped when smectic. Chem Mater. 2004;16:3606–3615. doi:10.1021/cm035294c.
   Web of Science ®Google Scholar
• Yelamaggad CV, Prasad SK, Nair GG, et al. A low-molar-mass, monodispersive, bent-rod dimer exhibiting biaxial nematic and smectic A phases. Angew Chem Int Ed. 2004;43:3429–3432. doi:10.1002/anie.200453908.
   PubMed Web of Science ®Google Scholar
• Tamba MG, Kosata B, Pelz K, et al. Mesogenic dimers composed of a calamitic and a bent-core mesogenic unit. Soft Matter. 2006;2:60–65. doi:10.1039/b511140d.
   PubMed Web of Science ®Google Scholar
• Imrie CT, Henderson PA. Liquid crystal dimers and higher oligomers: between monomers and polymers. Chem Soc Rev. 2007;36:2096. doi:10.1039/b714102e.
   PubMed Web of Science ®Google Scholar
• Tamba MG, Baumeister U, Pelzl G, et al. Banana-calamitic dimers: unexpected mesophase behaviour by variation of the direction of ester linking groups in the bent-core unit. Liq Cryst. 2010;37:853–874. doi:10.1080/02678291003798172.
   Web of Science ®Google Scholar
• Horčic M, Svoboda J, Seidler A, et al. W-shaped liquid crystalline dimers. RSC Adv. 2016;6:41972–41981. doi:10.1039/C6RA06268G.
   Web of Science ®Google Scholar
• Emsley JW, Luckhurst GR, Shilstone GN, et al. The preparation and properties of the α,ω-bis(4,4′-Cyanobiphenyloxy)alkanes: nematogenic molecules with a flexible core. Mol Cryst Liq Cryst. 1984;102:223–233. doi:10.1080/01406568408070532.
   Web of Science ®Google Scholar
• Barnes PJ, Douglass AG, Heeks SK, et al. An enhanced odd-even effect of liquid crystal dimers: orientational order in the α,ω -bis(4’-cyanobiphenyl-4-yl)alkanes. Liq Cryst. 1993;13:603–613. doi:10.1080/02678299308026332.
   Web of Science ®Google Scholar
• Ferrarini A, Luckhurst GR, Nordio PL, et al. Understanding the unusual transitional behaviour of liquid crystal dimers. Chem Phys Lett. 1993;214:409–417. doi:10.1016/0009-2614(93)85658-B.
   Web of Science ®Google Scholar
• Morris SM, Clarke MJ, Blatch AE, et al. Structure-flexoelastic properties of bimesogenic liquid crystals. Phys Rev E. 2007;75:041701. doi:10.1103/PhysRevE.75.041701.
   Web of Science ®Google Scholar
• Atkinson KL, Morris SM, Castles F, et al. Flexoelectric and elastic coefficients of odd and even homologous bimesogens. Phys Rev E. 2012;85:12701. doi:10.1103/PhysRevE.85.012701.
   Web of Science ®Google Scholar
• Cestari M, Frezza E, Ferrarini A, et al. Crucial role of molecular curvature for the bend elastic and flexoelectric properties of liquid crystals: mesogenic dimers as a case study. J Mater Chem. 2011;21:12303–12308. doi:10.1039/C1JM12233A.
   Web of Science ®Google Scholar
• Imrie CT, Luckhurst GR. Liquid crystal dimers and oligomers. In: Goodby JW, Collings PJ, Kato T, et al., editors. Handbook of liquid crsytals. Vol. 7. Weinheim: Wiley-VCH Verlag; 2014.
   Google Scholar
• Adlem K, Čopič M, Luckhurst GR, et al. Chemically induced twist-bend nematic liquid crystals, liquid crystal dimers, and negative elastic constants. Phys Rev E. 2013;88:22503. doi:10.1103/PhysRevE.88.022503.
   PubMed Web of Science ®Google Scholar
• Balachandran R, Panov VP, Vij JK, et al. Elastic properties of bimesogenic liquid crystals. Liq Cryst. 2013;40:681–688. doi:10.1080/02678292.2013.765973.
   Web of Science ®Google Scholar
• Borshch V, Kim Y-K, Xiang J, et al. Nematic twist-bend phase with nanoscale modulation of molecular orientation. Nat Commun. 2013;4:2635. doi:10.1038/ncomms3635.
   PubMed Web of Science ®Google Scholar
• Sebastián N, López DO, Robles-Hernández B, et al. Dielectric, calorimetric and mesophase properties of 1”-(2’,4-difluorobiphenyl-4’-yloxy)-9”-(4-cyanobiphenyl-4’-yloxy) nonane: an odd liquid crystal dimer with a monotropic mesophase having the characteristics of a twist-bend nematic phase. Phys Chem Chem Phys. 2014;16:21391–21406. doi:10.1039/c4cp03462g.
   PubMed Web of Science ®Google Scholar
• Yun C-J, Vengatesan MR, Vij JK, et al. Hierarchical elasticity of bimesogenic liquid crystals with twist-bend nematic phase. Appl Phys Lett. 2015;106:173102. doi:10.1063/1.4919065.
   Web of Science ®Google Scholar
• Cestari M, Diez-Berart S, Dunmur DA, et al. Phase behavior and properties of the liquid-crystal dimer 1′′,7′′-bis(4-cyanobiphenyl-4′-yl) heptane: A twist-bend nematic liquid crystal. Phys Rev E. 2011;84:031704. doi:10.1103/PhysRevE.84.031704.
   PubMed Web of Science ®Google Scholar
• Tripathi CSP, Losada-Pérez P, Glorieux C, et al. Nematic-nematic phase transition in the liquid crystal dimer CBC9CB and its mixtures with 5CB: A high-resolution adiabatic scanning calorimetric study. Phys Rev E. 2011;84:41707. doi:10.1103/PhysRevE.84.041707.
   PubMed Web of Science ®Google Scholar
• Šepelj M, Lesac A, Baumeister U, et al. Intercalated liquid-crystalline phases formed by symmetric dimers with an α,ω -diiminoalkylene spacer. J Mater Chem. 2007;17:1154. doi:10.1039/b612517d.
   Web of Science ®Google Scholar
• Chen D, Porada JH, Hooper JB, et al. Chiral heliconical ground state of nanoscale pitch in a nematic liquid crystal of achiral molecular dimers. PNAS. 2013;110:15931–15936. doi:10.1073/pnas.1314654110.
   PubMed Web of Science ®Google Scholar
• Memmer R. Liquid crystal phases of achiral banana-shaped molecules: a computer simulation study. Liq Cryst. 2002;29:483–496. doi:10.1080/02678290110104586.
   Web of Science ®Google Scholar
• Dozov I. On the spontaneous symmetry breaking in the mesophases of achiral banana-shaped molecules. Eur Lett. 2001;56:247–253. doi:10.1209/epl/i2001-00513-x.
   Google Scholar
• Meyer C, Luckhurst GR, Dozov I. Flexoelectrically driven electroclinic effect in the twist-bend nematic phase of achiral molecules with bent shapes. Phys Rev Lett. 2013;111:067801. doi:10.1103/PhysRevLett.111.067801.
   PubMed Web of Science ®Google Scholar
• Flory PJ. Statistical mechanics of chain molecules. New York (NY): Wiley-Interscience; 1969.
   Google Scholar
• Ferrarini A, Luckhurst GR, Nordio PL, et al. Prediction of the transitional properties of liquid crystal dimers. A molecular field calculation based on the surface tensor parametrization. J Chem Phys. 1994;100:1460. doi:10.1063/1.466625.
   Web of Science ®Google Scholar
• Ferrarini A, Luckhurst GR, Nordio PL. Even-odd effects in liquid crystal dimers with flexible spacers: a test of the rotational isomeric state approximation? Mol Phys. 1995;85:131–143. doi:10.1080/00268979500100991.
   Web of Science ®Google Scholar
• Ferrarini A, Luckhurst GR, Nordio PL, et al. Understanding the dependence of the transitional properties of liquid crystal dimers on their molecular geometry. Liq Cryst. 1996;21:373–382. doi:10.1080/02678299608032846.
   Web of Science ®Google Scholar
• Luckhurst GR. Liquid crystals: a chemical physicist’s view. Liq Cryst. 2005;32:1335–1364. doi:10.1080/02678290500423128.
   Web of Science ®Google Scholar
• Stocchero M, Ferrarini A, Moro GJ, et al. Molecular theory of dielectric relaxation in nematic dimers. J Chem Phys. 2004;121:8079. doi:10.1063/1.1794071.
   PubMed Web of Science ®Google Scholar
• Mandle RJ, Voll CCA, Lewis DJ, et al. Etheric bimesogens and the twist-bend nematic phase. Liq Cryst. 2016;43:13–21. doi:10.1080/02678292.2015.1091095.
   Web of Science ®Google Scholar
• Jansze SM, Martínez-Felipe A, Storey JMD, et al. A twist-bend nematic phase driven by hydrogen bonding. Angew Chemie Int Ed. 2015;54:643–646. doi:10.1002/anie.201409738.
   PubMed Web of Science ®Google Scholar
• Gorecka E, Vaupotič N, Zep A, et al. A twist-bend nematic (NTB) phase of chiral materials. Angew Chemie Int Ed. 2015;54:10155–10159. doi:10.1002/anie.201502440.
   PubMed Web of Science ®Google Scholar
• Zep A, Aya S, Aihara K, et al. Multiple nematic phases observed in chiral mesogenic dimers. J Mater Chem C. 2013;1:46–49. doi:10.1039/C2TC00163B.
   Web of Science ®Google Scholar
• Dunmur DA, de la Fuente MR, Perez Jubindo MA, et al. Dielectric studies of liquid crystals: the influence of molecular shape. Liq Cryst. 2010;37:723–736. doi:10.1080/02678292.2010.484913.
   Web of Science ®Google Scholar
• Robles-Hernández B, Sebastián N, de la Fuente MR, et al. Twist, tilt, and orientational order at the nematic to twist-bend nematic phase transition of 1″,9″-bis(4-cyanobiphenyl-4′-yl) nonane: A dielectric, 2HNMR, and calorimetric study. Phys Rev E. 2015;92:062505. doi:10.1103/PhysRevE.92.062505.
   PubMed Web of Science ®Google Scholar
• Hoffmann A, Vanakaras AG, Kohlmeier A, et al. On the structure of the Nx phase of symmetric dimers: inferences from NMR. Soft Matter. 2015;11:850–855. doi:10.1039/c4sm02480j.
   PubMed Web of Science ®Google Scholar
• López DO, Sebastian N, de la Fuente MR, et al. Disentangling molecular motions involved in the glass transition of a twist-bend nematic liquid crystal through dielectric studies. J Chem Phys. 2012;137:034502. doi:10.1063/1.4733561.
   PubMed Web of Science ®Google Scholar
• López DO, Robles-Hernández B, Salud J, et al. Miscibility studies of two twist-bend nematic liquid crystal dimers with different average molecular curvatures. A comparison between experimental data and predictions of a Landau mean-field theory for the NTB –N phase transition. Phys Chem Chem Phys. 2016;18:4394–4404. doi:10.1039/C5CP07605F.
   PubMed Web of Science ®Google Scholar
• Robles-Hernández B, Sebastián N, Salud J, et al. Molecular dynamics of a binary mixture of twist-bend nematic liquid crystal dimers studied by dielectric spectroscopy. Phys Rev E. 2016;93(6):062705. doi:10.1103/PhysRevE.93.062705.
   PubMed Web of Science ®Google Scholar
• Attard GS, Imrie CT, Karasz FE. Low molar mass liquid-crystalline glasses: preparation and properties of the α-(4-cyanobiphenyl-4’-oxy)- ω-(1-pyreniminebenzylidene-4’-oxy)alkanes. Chem Mater. 1992;4:1246–1253. doi:10.1021/cm00024a025.
   Web of Science ®Google Scholar
• Sebastián N, López DO, Diez-Berart S, et al. Effect of molecular flexibility on the nematic-to-isotropic phase transition for highly biaxial molecular non-symmetric liquid crystal dimers. Materials. 2011;4:1632–1647. doi:10.3390/ma4101632.
   PubMed Web of Science ®Google Scholar
• Sebastián N, de la Fuente MR, López DO, et al. Dielectric and thermodynamic study on the liquid crystal dimer α-(4-Cyanobiphenyl-4′-oxy)-ω-(1-pyreniminebenzylidene-4′-oxy)undecane (CBO11O·Py). J Phys Chem B. 2011;115:9766–9775. doi:10.1021/jp202796y.
   PubMed Web of Science ®Google Scholar
• Sebastián N, de la Fuente MR, López DO, et al. Overall dielectric study on the odd members of a highly nonsymmetric pyrene-based series of liquid crystal dimers. J Phys Chem B. 2013;117:14486–14496. doi:10.1021/jp406085r.
   PubMed Web of Science ®Google Scholar
• Diez-Berart S, López D, Salud J, et al. Two glass transitions associated to different dynamic disorders in the nematic glassy state of a non-symmetric liquid crystal dimer dopped with g-Alumina nanoparticles. Materials. 2015;8:3334–3351. doi:10.3390/ma8063334.
   Web of Science ®Google Scholar
• Salud J, López DO, Sebastián N, et al. Influence of the chain length on the nematic-to-isotropic phase transition for the odd members of a highly non-symmetric pyrene-based series of liquid crystal dimers. Liq Cryst. 2016;43:102–111. doi:10.1080/02678292.2015.1066890.
   Web of Science ®Google Scholar
• Cestari M. Atomistic modelling of liquid crystal materials properties: a theoretical and computational methodology. Padua: Universita degli studi di Padova; 2008.
   Google Scholar
• Maier W, Meier G. Eine einfache theorie der dielektrischen eigenschaften homogen orientierter kristallinflussiger phasen des nematischen typs. Z Naturforsch. 1961;16:262–267.
   Google Scholar
• Dunmur DA, Luckhurst GR, de la Fuente MR, et al. Dielectric relaxation in liquid crystalline dimers. J Chem Phys. 2001;115:8681–8691. doi:10.1063/1.1409365.
   Web of Science ®Google Scholar
• Nordio PL, Rigatti G, Segre U. Dielectric relaxation theory in nematic liquids. Mol Phys. 1973;25:129–136. doi:10.1080/00268977300100141.
   Web of Science ®Google Scholar
• Maier W, Saupe A. Eine einfache molecular-statistische theorie der nematischen kristallinflussigen phase. 1. Z Naturforsch. 1959;14:882–889.
   Google Scholar
• Maier W, Saupe A. Eine einfache molecular-statistische theorie der nematischen kristallinflussigen phase 2. Z Naturforsch. 1960;15:287–292.
   Web of Science ®Google Scholar
• Greco C, Luckhurst GR, Ferrarini A. Enantiotopic discrimination and director organization in the twist-bend nematic phase. Phys Chem Chem Phys. 2013;15:14961–14965. doi:10.1039/C3CP52222A.
   PubMed Web of Science ®Google Scholar
• Challa PK, Borshch V, Parri O, et al. Twist-bend nematic liquid crystals in high magnetic fields. Phys Rev E. 2014;89:060501. doi:10.1103/PhysRevE.89.060501.
   PubMed Web of Science ®Google Scholar
• Meyer C, Luckhurst GR, Dozov I. The temperature dependence of the heliconical tilt angle in the twist-bend nematic phase of the odd dimer CB7CB. J Mater Chem C. 2015;3:318–328. doi:10.1039/C4TC01927J.
   Web of Science ®Google Scholar
• Jokisaari JP, Luckhurst GR, Timimi BA, et al. Twist-bend nematic phase of the liquid crystal dimer CB7CB: orientational order and conical angle determined by 129 Xe and 2 H NMR spectroscopy. Liq Cryst. 2015;42:708–721. doi:10.1080/02678292.2015.1037576.
   Web of Science ®Google Scholar
• Urban S, Würflinger A. Relaxation phenomena: liquid crystals, magnetic systems, polymers, high-Tc superconductors, metallic glasses. In: Haase W, Wróbel S, editors. Berlin: Springer; 2003.
   Google Scholar
• Ramou E, Ahmed Z, Welch C, et al. The stabilisation of the Nx phase in mixtures. Soft Matter. 2016;12:888–899. doi:10.1039/c5sm01961c.
   PubMed Web of Science ®Google Scholar
• Ribeiro de Almeida RR, Zhang C, Parri O, et al. Nanostructure and dielectric properties of a twist-bend nematic liquid crystal mixture. Liq Cryst. 2014;41:1661–1667. doi:10.1080/02678292.2014.947346.
   Web of Science ®Google Scholar