One-Step Synthesis of a Liquid Crystal TB4A at Room Temperature

2011 ◽  
Vol 181-182 ◽  
pp. 168-172
Author(s):  
Qing Lan Ma ◽  
Bao Gai Zhai ◽  
Yuan Ming Huang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Liquid Crystal ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
Smectic A ◽  
Smectic C ◽  
Infrared Spectrometer ◽  
One Step

A rod-like liquid crystal (LC) N,N-(terephthalylidene) bis (4-n-butylaniline) (TB4A) was synthesized by one step at room temperature. The synthesized TB4A were investigated with nuclear magnetic resonance, fourier transform infrared spectrometer and ultraviolet-visible spectrophotometry, differential scanning calorimetry and polarizing optical microscopy. Our results demonstrated that the TB4A can form nematic, smectic A, smectic C, smectic F and smectic G LC phases.

Synthesis and Characterizations of a Rod-Like Liquid Crystal TBO16A

2011 ◽  
Vol 181-182 ◽  
pp. 135-138
Author(s):  
Qing Lan Ma ◽  
Bao Gai Zhai ◽  
Rui Xiong ◽  
Yuan Ming Huang
Keyword(s):  
Molecular Structure ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Liquid Crystal ◽  
Scanning Calorimetry ◽  
Absorption Data ◽  
H Nmr ◽  
Smectic A ◽  
Smectic A Phase

A rod-like liquid crystal (LC) N,N-(terephthalaldehyde) bis (4-n-hexadecyloxyaniline) (TBO16A) was synthesized and investigated by nuclear magnetic resonance (NMR), fourier transform infrared (FTIR), differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and ultraviolet-visible (UV-vis) spectrophotometry. The FTIR,1H NMR and UV-vis absorption data confirmed the molecular structure of TBO16A. Our results demonstrated that the TBO16A can form enantiotropic smectic A phase.

Evidence for room temperature mesomorphism in a mixed-valent diruthenium(II,III) quintapalmitoleate polymer

1998 ◽  
Vol 76 (11) ◽  
pp. 1520-1523
Author(s):  
Jennifer F Caplan ◽  
Christopher A Murphy ◽  
Susan Swansburg ◽  
Robert P Lemieux ◽  
T Stanley Cameron ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Powder Diffraction ◽  
Strong Evidence ◽  
Room Temperature ◽  
Variable Temperature ◽  
Mixed Valence ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystal Transition

The synthesis of Ru2(μ-O2CR)4(μ´-O2CR) (1), R = -CH2(CH2)6CH=CH(CH2)5CH3, has been achieved and characterization using elemental analysis and FTIR and UV-Vis spectroscopies undertaken. Strong evidence for a hexagonal discotic mesophase has been found using differential scanning calorimetry, variable-temperature polarizing optical microscopy, and X-ray powder diffraction. A solid to liquid crystal transition was found upon heating at 128°C and the mesophase is found to persist to room temperature upon cooling from 150°C. This is the first report of room temperature mesomorphism in a mixed-valent metallomesogen. Key words: ruthenium carboxylate, liquid crystal, metallomesogen, mixed valence, polymer.

Deep-Blue Photoluminescent Properties of a Liquid Crystal TB10A

2011 ◽  
Vol 181-182 ◽  
pp. 33-38 ◽  
Author(s):  
Qing Lan Ma ◽  
Rui Xiong ◽  
Yuan Ming Huang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Electronic Structures ◽  
Room Temperature ◽  
Tight Binding ◽  
Electronic Structure Calculations ◽  
Scanning Calorimetry ◽  
Deep Blue ◽  
Tight Binding Method ◽  
Structure Calculations

A typical liquid crystal (LC) N,N-(terephthalylidene) bis (4-decylbenzenamine) (TB10A) was firstly synthesized at room temperature. The synthesized LC TB10A were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), ultraviolet-visible (UV-vis) spectrophotometry, photoluminecence (PL) spectroscopy and electronic structure calculations. Upon the 325 nm excitation, the dilute tetrahydrofuran solutions of TB10A could give off blue PL. With Hückel tight-binding method, the electronic structures of the TB10A were calculated. Our results demonstrated that the deep-blue PL observed at about 489 nm (2.54 eV) can be assigned to theπ* →ntransition for the TB10A.

Optical Properties of Cholesteric Liquid Crystal Elastomer Film

2021 ◽  
Vol 888 ◽  
pp. 49-55
Author(s):  
Hong Yu Liu ◽  
Xiao Yan Wang ◽  
Xiang Yu Zang ◽  
Mei Tian
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Cholesteric Liquid Crystal ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Liquid Crystal Elastomer ◽  
Chemical Structures ◽  
Optical Micrograph ◽  
Infrared Spectrometer

A series of liquid crystal elastomer (LCE) films (ABC films) were prepared by polymerization of polymethylhydrosiloxane (PMHS), liquid crystal (LC) monomer cholesterol 4-(allyloxy) benzoate (MB) and cross-linking agent 4'-(undec-10-enoyloxy)-[1,1'-biphenyl]-4-yl dodec-11-enoate (MC) . The chemical structures and LC properties of the monomers and polymers were characterised by Fourier Transform Infrared Spectrometer (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), polarized optical micrograph (POM) and X-ray diffractometer (XRD). MB is a cholesteric LC and MC is a smectic LC. The ABC films are cholesteric LCEs. The temperature at which 5% weight loss occurred for the ABC films are around 300 °C. The glass transition temperature of ABC films increases with the increase of LC monomer MB content. The ABC films have a strong absorption around 200-330nm in the ultraviolet (UV) region, and the absorption range does not change with temperature.

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.

scholarly journals Thermotropic Liquid-Crystalline Properties of Viologens Containing 4-n-alkylbenzenesulfonates

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 77 ◽  
Author(s):  
Pradip Bhowmik ◽  
Anthony Chang ◽  
Jongin Kim ◽  
Erenz Dizon ◽  
Ronald Principe ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Liquid Crystalline ◽  
Metathesis Reaction ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Nuclear Magnetic Resonance Spectra ◽  
13C Nuclear Magnetic Resonance ◽  
Melting Transitions

A series of viologens containing 4-n-alkylbenzenesulfonates were synthesized by the metathesis reaction of 4-n-alkylbenzenesulfonic acids or sodium 4-n-alkylbezenesulfonates with the respective viologen dibromide in alcohols. Their chemical structures were characterized by Fourier Transform Infrared, 1H and 13C Nuclear Magnetic Resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry and polarizing optical microscopy. They formed LC phases above their melting transitions and showed isotropic transitions. As expected, all the viologen salts had excellent stabilities in the temperature range of 278–295 °C as determined by thermogravimetric analysis.

scholarly journals Progressive Steps of Polymorphic Transformation of Gabapentin Polymorphs Studied by Hot-stage FTIR Microspectroscopy

2010 ◽  
Vol 13 (1) ◽  
pp. 67 ◽  
Author(s):  
Cheng-Hung Hsu ◽  
Wen-Ting Ke ◽  
Shan-Yang Lin
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Solid State ◽  
Polymorphic Transformation ◽  
Three Dimensional ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ftir Microspectroscopy ◽  
Peak Intensity ◽  
One Step

Purpose. The aim of this study was to determine the progressive processes of polymorphic transformation of different gabapentin (GBP) polymorphs by using hot-stage Fourier transform infrared (FTIR) microspectroscopy. Methods. Four polymorphs of GBP were previously prepared and then identified by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, FTIR microspectroscopy and X-ray powder diffractometry. A novel hot-stage FTIR microspectroscopic technique was used to investigate the progressive steps of polymorphic transformation of each GBP polymorph sealed within two pieces of KBr plates. Results. Four polymorphs (Forms I, II, III and IV) of GBP were well characterized. The GBP form I was proven to be a monohydrate, but other GBP forms II-IV were anhydrous. Different thermal-induced progressive processes and steps of polymorphic interconversion of GBP polymorphs were clearly found from the changes in the three-dimensional IR spectral contour and peak intensity by using hot-stage FTIR microspectroscopy. The results also indicate that GBP form I was dehydrated and transformed to form III, and then converted to form IV; whereas GBP forms II and III directly transformed to form IV during heating. The GBP form IV was the last polymorph before the intramolecular lactamization of GBP. Conclusion. A one-step novel hot-stage FTIR microspectroscopy was successfully applied to simultaneously and continuously investigate the progressive processes and steps of thermal-induced polymorphic interconversion of GBP polymorph in the solid state.

scholarly journals Extraction of Lignin from Empty Fruit Bunch Fiber via Microwave-Assisted Acid Hydrotrope Solvent

2021 ◽  
Vol 1 (2) ◽  
pp. 26-33
Author(s):  
Rasidi Roslan ◽  
Muhammad Nor Arifin Yaakob ◽  
Ms Fathihah
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Reaction Time ◽  
Thermogravimetric Analysis ◽  
Empty Fruit Bunch ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Microwave Assisted

Lignin is a sub-product from lignocellulose apart from cellulose and hemicellulose that produced from empty fruit bunch fiber (EFB). Lignin has low solubility and reactivity due to its bulky macromolecule structre. Being one of the wastes that being generated in massive amount, many alternatives has been taken to transform lignin into valuable products. To do so, many reactions are needed for the lignin to go through. In this study, lignin will be extracted from empty fruit bunch (EFB) with the aid of acid hydrotrope concentration of 30 % and microwave assisted with various extraction heating time and temperature. Characterization of lignin is done using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Nuclear magnetic resonance (NMR) while Scanning Electron Microscopy (SEM) and X-ray Powder Diffraction (XRD) used to characterize residues. The highest percentage of lignin yield and its purity obtained are 19.47 % and 96.63 % with the reaction time and temperature of the microwave is 30 minutes and 90 °C. From Fourier Transform Infrared Spectroscopy (FTIR), a wide band at 3430.09 cm-1 and 3413.45 cm-1 are observed due to O-H stretching vibration. As for peak at 1123.17 cm-1 and 1051.26 cm-1, it correspond to syringyl and guaicyl unit in both lignin and raw EFB. As for Thermogravimetric analysis (TGA), it shows that lignin decomposes slowly compared to raw EFB due to the aromatic structure of lignin that is very stable, therefore leading to difficulty of decomposing while from Differential Scanning Calorimetry (DSC), after removing cellulose and hemicellulose, glass transition temperature (Tg) obtained from lignin DSC spectroscopy is 193.05 °C at heat flow of 1.15 mW/mg. Next, from Nuclear magnetic resonance (NMR) spectroscopy, the signals observed around 6.5 – 8.0 ppm indicate aromatic H in syringyl and guaiacyl unit only at lignin spectra while at 3.3 – 4.0 ppm, raw EFB has an intense peak compared to lignin which attribute to methoxyl group. When the residue of the lignin as well as the raw EFB powder is characterized using X-ray Powder Diffraction (XRD), the crystallinity index of the lignin with reaction time and temperature of the microwave 30 minutes and 90 °C is the highest, 69.28 %. As a conclusion, an admissible percent of lignin yield and purity is able to be obtained with addition of acid hydrotrope depending on the variables. From the spectroscopies characterization, it is proved that lignin characteristics and properties are compatible for the production of new and value added products.

Sign in / Sign up

Export Citation Format

Share Document