Synthesis and Properties of Photoisomerizable Derivatives of Isosorbide and Their Use in Cholesteric Filters

Lub, Johan; Nijssen, W. P. M.; Wegh, R. T.; Vogels, Joost P. A.; Ferrer, Ana

doi:10.1002/adfm.200500127

Cited by 46 publications

(38 citation statements)

References 33 publications

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“…During the exposure, the properties of a liquid crystalline phase are altered by E-Z photoisomerization of compounds containing an olefinic moiety, such as derivatives of stilbene or cinnamic acid. Such an E-Z isomerization process has successfully been applied in the manufacturing of cholesteric colour filters [12,13]. In this process the isomerizable compound also comprises a chiral moiety and the isomerized species exhibits a lower helical twisting power than the original species, resulting in an increase in the reflection wavelength of the cholesteric layer.…”

Section: Introductionmentioning

confidence: 99%

Patterned retarders prepared by photoisomerization and photopolymerization of liquid crystalline films

et al. 2006

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Isomerizable diacrylates derived from cinnamic acid are designed, synthesized and mixed with liquid crystalline diacrylates with the aim of making films with alternating birefringent and isotropic domains by applying the E-Z isomerization process at room temperature. The effects of the structure of the isomerizable-mesogenic group on the isotropization efficacy, the efficiency of the E-Z isomerization reaction, and film formation are discussed. Compounds derived from cyclohexyl cinnamate are proved to be good candidates that meet a whole set of parameters related to processing and application. These compounds exhibit a low nematic-toisotropic transition temperature. In addition, they show no yellowing upon irradiation, unlike similar compounds derived from phenyl cinnamate. To elucidate the origin of isotropization of the film by irradiation, the pure Z-isomer is prepared by photolysis of the E-isomer and subsequent chromatographic separation of both isomers. Analysis of reference samples containing the pure isomers reveals that the decrease in transition temperature can be attributed exclusively to the E-Z photoisomerization process. Finally, thin films with alternating birefringent and isotropic parts of 1006100 mm 2 are obtained by using a combination of photoisomerization in air and photopolymerization in a nitrogen atmosphere, which is referred to as photo-patterning.

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Section: Introductionmentioning

confidence: 99%

Patterned retarders prepared by photoisomerization and photopolymerization of liquid crystalline films

et al. 2006

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“…Selective mono‐acetylation of isosorbide ( 1 ) was carried out according to the literature . In a 25 mL round‐bottom flask equipped with a magnetic stirrer, 1 (1.460 g, 10.00 mmol) and lead acetate trihydrate (0.050 g, 0.13 mmol) were placed in 15 mL of acetic anhydride.…”

Section: Methodsmentioning

confidence: 99%

“…The mixture was extracted twice with 15 mL portions of water and twice with 10 mL portions of 5 wt% sodium hydrogen carbonate solution. The organic phase was dried over anhydrous magnesium sulfate, filtered off and distilled under reduced pressure to leave 2.970 g of a colourless viscous liquid (yield: 76%) . FTIR (neat; ν, cm −1 ): 2944 (m), 2872 (m), 1742 (s), 1369 (m), 1242 (s), 1372 (s), 1092 (m).…”

Section: Methodsmentioning

confidence: 99%

Nanocomposite materials based on isosorbide methacrylate/Cloisite 20A

Mansoori¹,

Hemmati²,

Eghbali³

et al. 2012

Polymer International

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This paper reports experiments on grafting of a new polymerizable monomer onto organophilic montmorillonite. The monomer, 5‐methacryloyloxy‐1,4:36‐D‐anhydrosorbitol (MAS), was synthesized by reacting methacryloyl chloride and isosorbide in the presence of Et3N as base. Then, Cloisite 20A was reacted with vinyltrichlorosilane to replace the edge hydroxyl groups of the clay with a vinyl moiety. Because the reaction liberates HCl, it was performed in the presence of sodium hydrogen carbonate to prevent the exchange of quaternary alkylammonium cations with H+ ions. Only the silanol groups on the edge of the clay react with vinyltrichlorosilane. After the reaction, the product maintained the same basal spacing as the precursor. The radical polymerization of the product with MAS as a vinyl monomer led to chemical grafting of the polymer onto the montmorillonite surface. The homopolymer formed during polymerization was separated from the grafted organoclay by Soxhlet extraction. Chemical grafting of the polymer onto Cloisite 20A was confirmed using infrared spectroscopy. The prepared nanocomposite materials and the grafted nanoparticles were studied using X‐ray diffraction and scanning and transmission electron microscopy. Exfoliated nanocomposite was obtained for 1 wt% clay loadings. The nanocomposites were studied using thermogravimetric and dynamic mechanical analyses. Improved thermal properties were observed for nanocomposites with 1–5 wt% clay content. © 2012 Society of Chemical Industry

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“…34 The HTP of a chiral component strongly depends on the molecular structure or stereochemistry of the chiral component. The HTP is the main parameter determining the helix pitch, which is a property of the chiral component that induces cholesteric polymers.…”

Section: Reflection Spectra Analysismentioning

confidence: 99%

Synthesis and optical properties of cholesteric liquid‐crystalline oligomers displaying reversible thermochromism

Wang

Zhang

2013

J of Applied Polymer Sci

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A series of side-chain liquid crystalline oligomers (P 1 -P 7 ) have been synthesized with cyclo(methylhydrogeno)siloxane and two cholesteric liquid crystalline monomers cholesteryl 4-(10-undecylen-1-yloxy)benzoate (M 1 ) and cholesterol 4-{6-[(4-(allyloxyl)benzoyl]-hexanoxocarbonyl}-benzoate (M 2 ). The chemical structures and liquid crystalline properties of the synthesized oligomers were investigated using various experimental techniques such as FTIR, 1 H-NMR, DSC, POM, and XRD. All monomers and chiral oligomers show a cholesteric mesophase with very wide mesophase temperature ranges. They appear highly thermally stable with decomposition temperatures (T d ) at 5% weight loss greater than 300 C. The optical properties of the oligmers have been characterized by reflection spectra and optical rotation analysis. All synthesized oligomers display colors at room temperature, and show reversible thermochromism within a wide temperature range (>120 C). The k max values of the oligomers also nearly coincide during the first, second, and third heating cycles. The specific rotation of each oligomer is very sensitive to temperature, and the specific rotation value of P 3 smoothly changes from 2 21.7 to 2 0.7 when it is heated. The optical properties of the oligomers offer tremendous potential for various optical applications.

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Synthesis and Properties of Photoisomerizable Derivatives of Isosorbide and Their Use in Cholesteric Filters

Cited by 46 publications

References 33 publications

Patterned retarders prepared by photoisomerization and photopolymerization of liquid crystalline films

Patterned retarders prepared by photoisomerization and photopolymerization of liquid crystalline films

Nanocomposite materials based on isosorbide methacrylate/Cloisite 20A

Synthesis and optical properties of cholesteric liquid‐crystalline oligomers displaying reversible thermochromism

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