Microphase separation in thermotropic liquid‐crystalline polysiloxanes with paired mesogens

Westphal, Steffi; Diele, Siegmar; Mädicke, A.; Kuschel, Frank; Scheim, U.; Rühlmann, Klaus; Hisgen, Bernd; Ringsdorf, Helmut

doi:10.1002/marc.1988.030090707

Cited by 34 publications

(11 citation statements)

References 12 publications

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“…In contrast to POSS, ODMS is a flexible silicon‐containing moiety, which makes it a favorable “coil” moiety in LC design . Due to the chemical incompatibility and large surface tension mismatch of ODMS with most organic materials, nanophase segregation is promoted, which leads to the formation of highly ordered nanostructured morphologies . In the case of rod‐coil motifs, smectic discotic, or more complex LC phases phases are observed, rather than nematic phases, which is a requirement for the preparation of sub‐5 nm hybrid organic/inorganic patterns.…”

Section: Fabrication Of Inorganic Sub‐5 Nm Patternsmentioning

confidence: 99%

Directed Self‐Assembly of Liquid‐Crystalline Molecular Building Blocks for Sub‐5 nm Nanopatterning

Nickmans

Schenning

2017

Advanced Materials

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The thin‐film directed self‐assembly of molecular building blocks into oriented nanostructure arrays enables next‐generation lithography at the sub‐5 nm scale. Currently, the fabrication of inorganic arrays from molecular building blocks is restricted by the limited long‐range order and orientation of the materials, as well as suitable methodologies for creating lithographic templates at sub‐5 nm dimensions. In recent years, higher‐order liquid crystals have emerged as functional thin films for organic electronics, nanoporous membranes, and templated synthesis, which provide opportunities for their use as lithographic templates. By choosing examples from these fields, recent progress toward the design of molecular building blocks is highlighted, with an emphasis on liquid crystals, to access sub‐5 nm features, their directed self‐assembly into oriented thin films, and, importantly, the fabrication of inorganic arrays. Finally, future challenges regarding sub‐5 nm patterning with liquid crystals are discussed.

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Section: Fabrication Of Inorganic Sub‐5 Nm Patternsmentioning

confidence: 99%

Directed Self‐Assembly of Liquid‐Crystalline Molecular Building Blocks for Sub‐5 nm Nanopatterning

Nickmans

Schenning

2017

Advanced Materials

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“…Recrystallization from ethanol and freeze-drying from benzene yielded the pure monomer 6. Yield: 0,75 g (37%) of a yellow solid; Rf: = 0,60 (petroleum ethedethyl acetate 2: l ) , DSC-behaviour see Tab ,7,58 [m;8Har0,,,_H2,T,6,7,23 [m;6Har0,.,4_H3,,6,96 [d;4Har0,,, -Hy,,,-biphenyl; 3J = 9 Hz], 5,82 [m;l H ,CH,5,14 [m;2H,C_H,4,67 …”

Section: Bis-ii-[4'-(4-(i-methylheptyloxy)-3-nitro Benzoyloxy)biphenymentioning

confidence: 99%

Dimesogenic ferroelectric polysiloxanes

Poths¹,

Zentel²

1994

Macromol. Rapid Commun.

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“…The backbone chains give the material polymeric properties and the flexible spacers groups to decouple the mesogenic units and allow them to form layer structures essentially unaffected by the motions of the backbone 12. In addition to what has been said above, when the main chains are very flexible as may be poly(siloxanes), liquid crystal copolymers are obtained where the lateral mesogen groups and the main chain form separated or segregated microphases2, 13–25 depending on spacer length.…”

Section: Introductionmentioning

confidence: 96%

“…In some cases, it has been found that the introduction of non‐mesogenic units in SCLCPs did not change the type of mesophase. However, in some cases, an increase of the number of phases was reported, that is, polymorphic mesophases, specially in the case of poly(siloxanes) 4–8. The incorporation of non‐mesogenic units can also hinder progressively the formation of a mesophase in a range, which depends on their chemical nature and length.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and properties of N‐maleimide side‐chain liquid crystalline copolymers

Ojeda

Quijada‐Garrido

Barrales‐Rienda

2010

J. Polym. Sci. A Polym. Chem.

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A homologous series of side‐chain liquid crystalline (SCLC) poly{[N‐[10‐((4‐(((4′‐n‐hexyloxy)benzoyl)oxy)phenoxy)carbonyl)‐n‐decyl]maleimide]‐co‐[N‐(n‐octadecyl)maleimide]} [(ME6)‐co‐(MI‐18)] random copolymers with various MI‐18 contents have been synthesized and their properties studied. The high content in threo‐disyndiotactic sequences of the maleimide main chain seems responsible for the stability of the highly ordered smectic mesophase. The relationship between structure and composition on thermotropic mesophase was investigated by polarizing optical microscopy, differential scanning calorimetry, and X‐ray diffraction. For copolymers with mesogenic unit contents less than ∼0.655 molar fraction the transition from (SA) texture to isotropic (I) is maintained, as shown by the TCl, ΔHCl and ΔSCl amounts and intermolecular spacing 4.42–4.53 Å and intralayer correlation lengths of 44.2–45.2 Å. The layer thickness does not appreciably depend on copolymer composition. However, copolymers with non‐mesogenic comonomer MI‐18 molar contents larger than >0.655 molar fraction X(M), are no longer liquid crystalline materials, despite its packing is preserved without any detectable appearance of birefringence. Thermodynamic boundaries of the liquid crystalline state have been established through a phase diagram. The properties of this n‐hexyloxy pendant group‐based series are compared to those of the analogous materials containing methoxy pendant groups (ME1), and differences are accounted for in terms of the local side‐chain packing within the mesophase. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

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Microphase separation in thermotropic liquid‐crystalline polysiloxanes with paired mesogens

Cited by 34 publications

References 12 publications

Directed Self‐Assembly of Liquid‐Crystalline Molecular Building Blocks for Sub‐5 nm Nanopatterning

Directed Self‐Assembly of Liquid‐Crystalline Molecular Building Blocks for Sub‐5 nm Nanopatterning

Dimesogenic ferroelectric polysiloxanes

Synthesis, characterization and properties of N‐maleimide side‐chain liquid crystalline copolymers

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