Direkt zum Inhalt
Merck
  • Hierarchical superstructures from a star-shaped molecule consisting of a cyclic oligosiloxane with cyanobiphenyl moieties.

Hierarchical superstructures from a star-shaped molecule consisting of a cyclic oligosiloxane with cyanobiphenyl moieties.

Soft matter (2014-11-20)
Dae-Yoon Kim, Minwook Park, Sang-A Lee, Soeun Kim, Chih-Hao Hsu, Namil Kim, Shiao-Wei Kuo, Tae-Ho Yoon, Kwang-Un Jeong
ZUSAMMENFASSUNG

Unconventional star-shaped liquid crystals (abbreviated as SiLCs) were successfully synthesized by chemically connecting four cyanobiphenyl anisotropic mesogens to the periphery of a super-hydrophobic and ultra-flexible cyclic tetramethyltetrasiloxane ring with flexible hexyl chains. Based on the combined experimental techniques of differential scanning calorimetry (DSC), cross-polarized optical microscopy (POM), solid-state carbon-13 ((13)C) nuclear magnetic resonance (NMR) spectroscopy and one-dimensional (1D) wide-angle X-ray diffraction (WAXD), it was found that the SiLC molecule exhibited the monotropic phase transition from a LC phase to a crystalline phase. The crystalline phase was only detected during slow heating processes above its glass transition temperature, while a LC phase was formed both during cooling and during heating processes. The hierarchical superstructures were identified from the structure-sensitive 2D WAXD of the macroscopically oriented SiLC film and confirmed by selected area electron diffraction (SAED) of the SiLC single crystals. The molecular packing symmetry in the monoclinic unit cell was further investigated by computer simulations on the real and reciprocal spaces. Macroscopically oriented SiLC hierarchical superstructures on the different length scales may provide the targeted physical properties, which can allow us to apply SiLC molecules in the fields of electro-optical devices and nonlinear optics.

MATERIALIEN
Produktnummer
Marke
Produktbeschreibung

Sigma-Aldrich
N,N-Dimethylformamid, ACS reagent, ≥99.8%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
N,N-Dimethylformamid, suitable for HPLC, ≥99.9%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Toluol, ACS reagent, ≥99.5%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, ACS reagent, ≥99.0%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, anhydrous, free-flowing, Redi-Dri, ACS reagent, ≥99%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, puriss. p.a., ACS reagent, anhydrous, ≥99.0% (T)
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, reagent grade, ≥98%, powder, −325 mesh
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
N,N-Dimethylformamid, ReagentPlus®, ≥99%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
N,N-Dimethylformamid, for molecular biology, ≥99%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
N,N-Dimethylformamid, biotech. grade, ≥99.9%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, ReagentPlus®, 99%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, 99.995% trace metals basis
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, anhydrous, powder, 99.99% trace metals basis
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, BioXtra, ≥99.0%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
6-Brom-1-hexen, 95%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
2,4,6,8-Tetramethylcyclotetrasiloxan, ≥98.5%, ≥99.999% trace metals basis
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Supelco
Dimethylformamid, Pharmaceutical Secondary Standard; Certified Reference Material
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
4,4′-Bis(N-carbazolyl)-1,1′-Biphenyl, 97%
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
4,4′-Bis(N-carbazolyl)-1,1′-Biphenyl, sublimed grade, 99.9% trace metals basis
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, BioUltra, anhydrous, ≥99.0% (T)
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Sigma-Aldrich
Kaliumcarbonat, meets USP testing specifications
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge
Supelco
N,N-Dimethylformamid, analytical standard
SKU
Packungsgröße
Verfügbarkeit
Preis
Menge