scholarly journals Synthesis and Characterization of Lateral Fluoro-substituents Liquid Crystals

2021 ◽  
Vol 11 (5) ◽  
pp. 12495-12505
Keyword(s):  
Molecular Structure ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Linkage Group ◽  
Optical Microscope ◽  
Synthesis And Characterization ◽  
Spectroscopic Techniques ◽  
Dielectric Measurements ◽  
Scanning Calorimetry

Lateral difluoro substituent liquid crystal based on a three-aromatic core has been synthesized. It has been designed to correlate the molecular structure and mesomorphism with reference to the difluoro substituent and -COO- linkage group. This compound was characterized by elementary analyses and spectroscopic techniques such as FTIR and 1H-NMR. The synthesis compound's mesomorphic behavior was studied by polarizing optical microscope, differential scanning calorimetry, and dielectric measurements. The recent investigation reveals only SmB phase.

scholarly journals Synthesis, Mesomorphism and the Optical Properties of Alkyl-deuterated Nematogenic 4-[(2,6-difluorophenyl)ethynyl]biphenyls

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4653
Author(s):  
Jakub Herman ◽  
Piotr Harmata ◽  
Michał Czerwiński ◽  
Olga Strzeżysz ◽  
Marta Pytlarczyk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Optical Properties ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
Synthesis And Characterization ◽  
Molecular Approach ◽  
Scanning Calorimetry

The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.

scholarly journals Synthesis and characterization of solid 2-methoxycinnamylidenepyruvic acid

2008 ◽  
Vol 33 (4) ◽  
pp. 61-68 ◽  
Author(s):  
C. T. de Carvalho ◽  
A. B. Siqueira ◽  
E. Y. Ionashiro ◽  
M. Pivatto ◽  
M. Ionashiro
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Molecular Geometry ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Purity Determination

The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized and characterized for nuclear magnetic resonance (¹H and 13C NMR), mass spectrometry (MS), Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The application of DSC for purity determination is well documented in literature and is used in the analysis of pure organic compounds. The molecular geometry and vibrational frequencies of 2-MeO-HCP have been calculated.

Characterization of Process Induced Contamination and Residues on Semiconductor Components Via FTIR and Raman Microanalysis

2001 ◽  
Vol 7 (S2) ◽  
pp. 152-153
Author(s):  
H. Gotts
Keyword(s):  
Molecular Structure ◽  
Yield Enhancement ◽  
Spectroscopic Techniques ◽  
Bulk Materials ◽  
Scanning Calorimetry ◽  
Vis Spectroscopy ◽  
Classical Technique ◽  
Raman Microprobe ◽  
Scanning Electron

FTIR and Raman microanalysis may be used as a powerful combination to determine the identity, and hence infer the source, of contaminant particles which diminish yields of semiconductor components and devices. The complimentarity of these techniques arises from the underlying spectroscopic selection rules.Vibrational spectroscopic techniques are commonly used to characterize the molecular structure of bulk organic materials. These bulk materials typically represent purified fractions of components which may be further investigated with various classical instrumental techniques such as Differential Scanning Calorimetry (DSC), Nuclear Magnetic Resonance (NMR) spectroscopy, UV-Vis spectroscopy. However, these classical technique may have limited value for the interrogation of small impure particles or materials of limited quantity(ng.).Elemental techniques such as Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy are enhanced by the specificity of FTIR Microprobe Spectroscopy and Raman Microprobe Spectroscopy which are now used in process laboratories to characterize and identify particulate and thin film residues with the intent of device yield enhancement.

Synthesis and Characterization of Stilbene Derivatives for Possible Incorporation as Smart Additives in Polymers Used as Packaging Films.

1997 ◽  
Vol 50 (4) ◽  
pp. 425 ◽  
Author(s):  
Gary M. Day ◽  
Owen T. Howell ◽  
Michael R. Metzler ◽  
Paul D. Woodgate
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Packaging Films ◽  
Multiple Phase ◽  
Liquid Crystalline Phases ◽  
Crystal Properties ◽  
Stilbene Derivatives

Several series of stilbene derivatives for possible use as smart additives in polymers used as packaging films have been prepared and characterized. Differential scanning calorimetry was performed on some of the stilbenes in order to determine any liquid crystal properties. Those compounds which had multiple phase transitions were also shown to have two liquid crystalline phases according to optical microscopy.

Synthesis and Characterization of Smectic Polymorphism in Higher Homologues of N-(p-n-Alkoxybenzylidene)-p-n-(Alkylanilines)

2003 ◽  
Vol 58 (2-3) ◽  
pp. 103-108 ◽  
Author(s):  
Venkata G. K. M. Pisipati ◽  
A. K. George ◽  
Ch. Srinivasu ◽  
P. N. Murty
Keyword(s):  
Differential Scanning Calorimetry ◽  
Alkyl Chain ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Phase Variants ◽  
Miscibility Studies

Higher homologues of N-(p-n-alkoxybenzylidene)-p-n-alkylanilines (nO.m) compounds with n = 15 and 18 and m = 4 to 10, 12, 14, and 16 have been synthesized and the smectic polymesomorphism is studied. The transition temperatures were obtained both from thermal polarizing microscopy and differential scanning calorimetry. The compounds exhibit a smectic-F phase from the isotropic melt, their amount increasing with the number of the alkoxy chain. This implies that with the alkoxy chain number the manifestation of smectic-F occurs with shorter alkyl chain. The phase variants were confirmed with miscibility studies

Synthesis and characterization of novel tetrakis (3-hydroxypropylmercapto)-substituted phthalocyanines

2013 ◽  
Vol 17 (06n07) ◽  
pp. 573-586 ◽  
Author(s):  
Çiğdem Yağcı ◽  
Ahmet Bilgin
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Synthesis And Characterization ◽  
The Novel ◽  
Scanning Calorimetry ◽  
Metal Free ◽  
Visible Spectra ◽  
Ft Ir ◽  
Aromatic Nitro

A phthalonitrile precursor 4-(3-hydroxypropylmercapto)phthalonitrile (3) was synthesized via a base-catalyzed nucleophilic aromatic nitro displacement of 4-nitrophthalonitrile with the 3-mercapto-1-propanol. A novel tetrasubstituted metal-free phthalocyanine (4) ( M = 2 H ) and its metal complexes (5–8) ( M = Zn , Ni , Cu and Co ) bearing 3-hydroxypropylmercapto moieties were prepared by the cyclotetramerization reaction of (3) with the appropriate materials. The visible spectra of the zinc(II) phthalocyanine (5) was recorded with different concentrations and different ions as Ag +, Hg 2+ and Pb 2+ in DMF and also with different solvents as dimethylformamide and pyridine. Fluorescence spectrum of the compound (5) was also studied. Temperature and frequency dependence of AC conductivity for (4–8) was investigated in air and under vacuum and were found to be ~10-8–10-5 S.m-1. Thermal properties of the phthalocyanines were examined by differential scanning calorimetry. All the novel compounds have been characterized by elemental analysis, UV-vis, FT-IR, NMR and MS spectral data and DSC techniques.

Characterization of Main-Chain Liquid Crystal Elastomers by Using Differential Scanning Calorimetry (DSC) Method

2015 ◽  
Vol 1123 ◽  
pp. 69-72 ◽  
Author(s):  
Supardi ◽  
Y. Yusuf ◽  
Harsoyo
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Basic Principle ◽  
Main Chain ◽  
Scanning Calorimetry ◽  
Mechanical Effects ◽  
Liquid Crystal Elastomers ◽  
Dsc Method

We performed an experiment to characterize the four samples of main chain liquid crystal elastomers (MCLCEs) by using differential scanning calorimetry (DSC) method. Basic principle of this method is that difference in the amount of heat required to increase the temperature of the sample and reference is measured as a function of temperature. The temperature between the sample and reference is maintained nearly the same throughout the experiment. There were four samples with different concentrations of crosslinker we have taken, namely 8%, 12%, 14%, and 16%. The results showed that the phase transition from nematic to isotropic obtained by this method had correlation with their thermo-mechanical effects.

Synthesis and Characterization of Segmented Copolymers of a Methylated Polyamide and a Thermotropic Liquid Crystalline Polyester

1989 ◽  
Vol 171 ◽  
Author(s):  
Gregory T. Pawlikowski ◽  
R. A. Weiss ◽  
S. J. Huang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Composite Material ◽  
Block Copolymer ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Segmented Copolymers ◽  
Liquid Crystalline Polyester ◽  
Solution Polycondensation

ABSTRACTA block copolymer consisting of liquid crystalline polyester segments and methylated polyamide segments has been synthesized. Solution polycondensation of acid chloride end-capped poly(terephthaloyl phenylhydroquinone) (LCP portion) with an amine terminated poly(N,N'-dimethylethylene sebacamide) was utilized to prepare the block copolymer. Characterization by differential scanning calorimetry, infrared spectroscopy, thermogravimetric analysis, optical microscopy and elemental analysis has been performed to verify the existence of the block copolymer that may have potential as a molecular composite material or self-reinforcing thermoplastic.

Synthesis and Characterization of a Cholesteric Liquid Crystal Cholesteryl Nonanoate

2010 ◽  
Vol 428-429 ◽  
pp. 94-97 ◽  
Author(s):  
Yuan Ming Huang ◽  
Ye Tang Guo ◽  
Qing Lan Ma ◽  
Wei Wei Liu
Keyword(s):  
Liquid Crystal ◽  
Cholesteric Liquid Crystal ◽  
Synthesis And Characterization ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Selective Reflection ◽  
Cholesteric Phase ◽  
Polarized Optical Microscopy ◽  
Clearing Point

A cholesteric liquid crystal cholesteryl nonanoate was synthesized and then characterized by means of differential scanning calorimetry and polarized optical microscopy. As temperature decreased from its clearing point, cholesteric phase was formed for cholesteryl nonanoate and accompanied by continuous evolution of colors in the focal conic textures. Furthermore, beautiful spherulite crystals were observed to grow out of the cholesteric phase as the crystallization continued. The evolution of the colors in recorded textures was contributed to temperature-dependent selective reflection of the liquid crystal.

Unprecedented transformation of [I−·I3−] to [I42−] polyiodides in the solid state: structures, phase transitions and characterization of dipyrazolium iodide triiodide

2015 ◽  
Vol 44 (42) ◽  
pp. 18447-18458 ◽  
Author(s):  
M. Węcławik ◽  
P. Szklarz ◽  
W. Medycki ◽  
R. Janicki ◽  
A. Piecha-Bisiorek ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Solid State ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Solid State Structures

Dipyrazolium iodide triiodide, [C3N2H5+]2[I−·I3−], has been synthesized and studied by means of X-ray diffraction, differential scanning calorimetry, dielectric measurements, and UV-Vis spectroscopy.

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