Influence of Cooling Rates on Phase Transitions of Bent-Core Liquid Crystal 1,3-Phenylene-bis[4-(hexylcarboyloxyl)benzylideneamine]

2010 ◽  
Vol 428-429 ◽  
pp. 247-250 ◽  
Author(s):  
Yuan Ming Huang ◽  
Qing Lan Ma ◽  
Bao Gai Zhai
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Cooling Rate ◽  
Scanning Calorimetry ◽  
Slow Cooling ◽  
Cooling Rates ◽  
Polarized Optical Microscopy ◽  
Fast Cooling

The influence of cooling rate on the phase transitions of a three-benzene-ring containing bent-core liquid crystal 1,3-phenylene-bis[4-(hexylcarboyloxyl)benzylideneamine] has been investigated by means of differential scanning calorimetry and polarized optical microscopy. Our results show that the cooling rates in the second cooling run pose significant effects on the phase transitions of the bent-core liquid crystal despite the cooling rates in the first cooling run pose little effects on the phase transitions. In the second cooling run, the banana phases survived only when the cooling rates were in the range of 14~15oC/min whereas both slow cooling rates which were less than 13oC/min and fast cooling rates which were higher than 16oC/min made the banana phases disappeared.

Dependence of Phase Transition of a Bent-Core Liquid Crystal on the Heating Rate

2010 ◽  
Vol 663-665 ◽  
pp. 787-790 ◽  
Author(s):  
Qing Lan Ma ◽  
Yuan Ming Huang
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Heating Rate ◽  
Broad Peak ◽  
Crystal Phase ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Crystal Compound

A bent-core liquid crystal compound N,N-bis (4-propoxybenzylidene)benzene- 1,3-diamine was synthesized. Phase transition properties of the synthesized compound with the deferent heating rate were characterized with differential scanning calorimetry and polarized optical microscopy. , respectively. Our results demonstrated that the bent-core compound exhibited the completely undivided multi-phases in heating-rate ranges from 1oC/min to 6oC/min while it showed a broad-peak crystal phase in higher heating-rate ranges of 7-10oC/min for the first heating.

Synthesis and Mesomorphic Properties of a Series of Cholesteric Liquid Crystals

2010 ◽  
Vol 663-665 ◽  
pp. 759-762 ◽  
Author(s):  
Qing Lan Ma ◽  
Yuan Ming Huang
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Optical Microscopy ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Phase Transition Temperatures ◽  
Second Category ◽  
Mesomorphic Properties

A series of cholesterol liquid crystal compounds was synthesized. Phase-transition temperatures and mesomorphic textures of these synthesized compounds were characterized with differential scanning calorimetry and polarized optical microscopy, respectively. In these molecules the terminal ester chains CnH2n-1COO-, where n was the number of carbon atoms in the terminal ester chains, were linked to the cholesterol core. All of the synthesized cholesterol compounds exhibited mesophases for the first heating. However, as temperature decreased from their clearing points, their micrographs can also be divided into two categories, the first category exhibits branch-like mesophase textures for n in the range of 1-10 while the second category exhibits branch-like crystal textures for n in the range of 11-18.

scholarly journals New cholesteryl containing bent core liquid crystals

2013 ◽  
Vol 78 (5) ◽  
pp. 669-680 ◽  
Author(s):  
Cosmin-Constantin Huzum ◽  
Irina Carlescu ◽  
Gabriela Lisa ◽  
Dan Scutaru
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Optical Microscopy ◽  
Liquid Crystalline ◽  
Benzoic Acids ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Acyl Chlorides ◽  
Esterification Reactions

The paper presents the synthesis and mesomorphic behavior of two new series of bent core liquid crystalline compounds based on a 1,3-dihydroxybezene core and containing a cholesteryl 6-oxyhexanoate wing. The two series were obtained by the esterification of the cholesteryl 6-(3-hydroxyphenoxy)hexanoate core with some 4-((4-(n-alkyloxy)phenyl)azo)benzoic acids (n-alkyl = n-hexyl ? n-dodecyl) or 4-(4-(n-alkyloxy)benzoyloxy)benzoic acids (n-alkyl = n-hexyl ? n-decyl). The esterification reactions were performed via the corresponding acyl chlorides or with the DCC / DMAP system. All the synthesized compounds evidenced enantiotropic liquid crystalline properties, with smectic type textures, when investigated by means of differential scanning calorimetry and polarized optical microscopy. Isotropisation and isotropic to liquid crystal transitions were relatively low (between 89 ? 1460C). The compounds containing the azo-aromatic linking group presented the largest range of stability of the mesophases (between 42 and 870C). All the investigated compounds were thermally stable in the existence range of the mesophases.

Synthesis and Mesomorphic Properties of Three-Ring Containing Bent-Core Liquid Crystal 1,3-Phenylene-bis(4-butoxybenzylideneamine)

2010 ◽  
Vol 428-429 ◽  
pp. 167-170
Author(s):  
Yuan Ming Huang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Cyclic Heating ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Temperature Range ◽  
Heating And Cooling ◽  
Mesomorphic Properties

A three-ring containing bent-core compound 1,3-phenylene-bis(4-butoxybenzylidene amine) was synthesized and characterized with differential scanning calorimetry and polarized optical microscopy. It exhibited mesophases in the temperature range of 48-54oC for the first cyclic heating and cooling. Our results demonstrated that three-ring containing bent-core molecules can form mesophases.

scholarly journals 2-{3,5-Bis-[5-(3,4-didodecyloxyphenyl)thien-2-yl]phenyl}-5-(3,4-didodecyloxyphenyl)thiophene

Molbank ◽  
10.3390/m1225 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1225
Author(s):  
Matthias Jochem ◽  
Heiner Detert
Keyword(s):  
Liquid Crystal ◽  
Optical Microscopy ◽  
Boronic Acid ◽  
Suzuki Coupling ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
The Core ◽  
Discotic Liquid Crystal ◽  
Acid Catalyzed

Star-shaped compounds are widely recognized as emerging materials for optical and electrical applications and as scaffolds of discotic liquid crystal. While the C3-symmetrical tri(phenylthienyl)benzene is the core for several electroopotical materials, no liquid crystal with this scaffold has yet been reported. Acid-catalyzed cyclocondensation of bromoacetylthiophene gives a C3-symmetrical star, threefold Suzuki coupling results in extension of the conjugated system. With 3,4-didodecylocyphenyl boronic acid, a star with a large rigid conjugated system and flexible aliphatic periphery is obtained. Differentials scanning calorimetry and polarized optical microscopy reveal an enantiotropic mesophase from 66 °C to 106 °C.

Mesophase Studies and Charge Transportation Properties of 3,6-dicarbethoxy-2,7,10,11-tetra-pentyloxytriphenylene

2011 ◽  
Vol 181-182 ◽  
pp. 193-196
Author(s):  
Chun Xiu Zhang ◽  
Jia Ling Pu ◽  
Hao Wu ◽  
Ao Zhang ◽  
Ming Xia Zhang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Chemical Structure ◽  
Room Temperature ◽  
Time Of Flight ◽  
Scanning Calorimetry ◽  
Columnar Phase ◽  
Discotic Liquid Crystal ◽  
Time Of Flight Method

In this study, a triphenylene-based discotic liquid crystal 3,6-dicarbethoxy-2,7,10,11-tetra-pentyloxytriphenylene was synthesized. The chemical structure was characterized by FTIR, 1HNMR.The mesophases of the material synthesized here was characterized by using polarizing optical microscopy (POM), differential scanning calorimetry (DSC). It was found that the compound displayed columnar phase during cooling at 164.7 °C and the columnar phase can be preserved even at room temperature. The charge transportation properties of the compound were measured by using time-of-flight method.

Synthesis and Application of a Novel Liquid Crystal Monomer 1,4-di-[4-(3-acryloyloxyhexyloxy)benzoyloxy]-2-methyl Benzene

2014 ◽  
Vol 875-877 ◽  
pp. 3-8
Author(s):  
Gui Yu Zhang ◽  
Hong Bo Lu ◽  
Wei Bing Xu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Polymer Network ◽  
Liquid Crystal Phase ◽  
3D Display ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Polymer Stabilized ◽  
Methyl Benzene ◽  
Scanning Electron

A novel liquid crystal monomer 1, 4-Di-[4-(3-acryloyloxyhexyloxy) benzoyloxy]-2-methyl benzene (LCM) was synthesized and characterized by 1H NMR, differential scanning calorimetry (DSC) and polarized optical microscopy (POM). LCM possesses liquid crystal phase between 68 to 124 °C. A f-ast response polymer stabilized cholesteric texture (PSCT) film was prepared based on LCM, and t-he response time was less than 1 ms, which can be applied in true 3D display. In addition, the morp-hology of the polymer network was investigated by scanning electron microscope (SEM).

Sign in / Sign up

Export Citation Format

Share Document