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Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers

Six novel bent-shaped monomers viz. substituted 1,3-phenylene bis-{ 4-[ 4-(n-allyloxyalkyloxy) phenylazo ]benzoate} 5a-c and substituted 1,3-phenylene bis-{ 4-[ 4-(n-allyloxyalkyloxy)-3- fluorophenylazo]benzoate} 5d-f in which azobenzene moiety in the periphery and resorcinol as central unit and po...

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Main Author: Lutfor Rahman
Format: Research Report
Language:English
English
Published: Universiti Malaysia Sabah 2009
Subjects:
QD Chemistry
Online Access:https://eprints.ums.edu.my/id/eprint/23644/1/Synthesis%20and%20Electro-Optical%20investigation%20of%20Fluorine%20substituted%20Banana-Shaped%20Liquid%20Crystals%20Monomers.pdf
https://eprints.ums.edu.my/id/eprint/23644/7/Synthesis%2C%20purification%20and%20characterization%20of%20new%20Chitosan%20Derivatives.pdf
https://eprints.ums.edu.my/id/eprint/23644/
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spelling my.ums.eprints.236442020-09-30T02:54:37Z https://eprints.ums.edu.my/id/eprint/23644/ Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers Lutfor Rahman QD Chemistry Six novel bent-shaped monomers viz. substituted 1,3-phenylene bis-{ 4-[ 4-(n-allyloxyalkyloxy) phenylazo ]benzoate} 5a-c and substituted 1,3-phenylene bis-{ 4-[ 4-(n-allyloxyalkyloxy)-3- fluorophenylazo]benzoate} 5d-f in which azobenzene moiety in the periphery and resorcinol as central unit and polymerizable double bonds at both ends of all the molecules were synthesized and characterized. Mesophase behavior was investigated using polarizing optical microscopy, DSC and XRD measurements. All six members of the family show an intercalated smectic (Smintercal) phase. One of these azo dyes has been Investigated for guest host effect in which liquid crystal is the guest and bent core azo dye is the host, 5% of this azo dye is mixed with 95 % of liquid crystal E7. The absorbance study as a function of wavelength at different time intervals with fixed UV intensity (intensity lmW/cm2). When the radiation is switched off and the sample is left In the dark, reverse isomerization takes place with the sample transforming in to the nematic phase from isotropic phase and consequently absorbance increases. Absorbance spectrum has been recorded at certain Intervals to check the thermal back relaxation process. After 50000 seconds (around 13 hours), system fully transforms to original nematic state. It takes very long time (almost 13 hours) to convert back to trans state which is useful for creation of optical image storage devices. Thus, one of azo dye is mixed with liquid crystal as a guest, showed greater increase in thermal back relaxation time which is useful for creation of optical image storage devices. Universiti Malaysia Sabah 2009 Research Report NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/23644/1/Synthesis%20and%20Electro-Optical%20investigation%20of%20Fluorine%20substituted%20Banana-Shaped%20Liquid%20Crystals%20Monomers.pdf text en https://eprints.ums.edu.my/id/eprint/23644/7/Synthesis%2C%20purification%20and%20characterization%20of%20new%20Chitosan%20Derivatives.pdf Lutfor Rahman (2009) Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers. (Unpublished)
institution Universiti Malaysia Sabah
building UMS Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Sabah
content_source UMS Institutional Repository
url_provider http://eprints.ums.edu.my/
language English
English
topic QD Chemistry
spellingShingle QD Chemistry
Lutfor Rahman
Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers
description Six novel bent-shaped monomers viz. substituted 1,3-phenylene bis-{ 4-[ 4-(n-allyloxyalkyloxy) phenylazo ]benzoate} 5a-c and substituted 1,3-phenylene bis-{ 4-[ 4-(n-allyloxyalkyloxy)-3- fluorophenylazo]benzoate} 5d-f in which azobenzene moiety in the periphery and resorcinol as central unit and polymerizable double bonds at both ends of all the molecules were synthesized and characterized. Mesophase behavior was investigated using polarizing optical microscopy, DSC and XRD measurements. All six members of the family show an intercalated smectic (Smintercal) phase. One of these azo dyes has been Investigated for guest host effect in which liquid crystal is the guest and bent core azo dye is the host, 5% of this azo dye is mixed with 95 % of liquid crystal E7. The absorbance study as a function of wavelength at different time intervals with fixed UV intensity (intensity lmW/cm2). When the radiation is switched off and the sample is left In the dark, reverse isomerization takes place with the sample transforming in to the nematic phase from isotropic phase and consequently absorbance increases. Absorbance spectrum has been recorded at certain Intervals to check the thermal back relaxation process. After 50000 seconds (around 13 hours), system fully transforms to original nematic state. It takes very long time (almost 13 hours) to convert back to trans state which is useful for creation of optical image storage devices. Thus, one of azo dye is mixed with liquid crystal as a guest, showed greater increase in thermal back relaxation time which is useful for creation of optical image storage devices.
format Research Report
author Lutfor Rahman
author_facet Lutfor Rahman
author_sort Lutfor Rahman
title Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers
title_short Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers
title_full Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers
title_fullStr Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers
title_full_unstemmed Synthesis and Electro-Optical investigation of Fluorine substituted Banana-Shaped Liquid Crystals Monomers
title_sort synthesis and electro-optical investigation of fluorine substituted banana-shaped liquid crystals monomers
publisher Universiti Malaysia Sabah
publishDate 2009
url https://eprints.ums.edu.my/id/eprint/23644/1/Synthesis%20and%20Electro-Optical%20investigation%20of%20Fluorine%20substituted%20Banana-Shaped%20Liquid%20Crystals%20Monomers.pdf
https://eprints.ums.edu.my/id/eprint/23644/7/Synthesis%2C%20purification%20and%20characterization%20of%20new%20Chitosan%20Derivatives.pdf
https://eprints.ums.edu.my/id/eprint/23644/
_version_ 1760230135148052480
score 13.211869

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