Characterization, liquid crystallinity and spin-coated films of some metalated 1,4,8,11,15,18,22,25-octaalkyl tetrabenzo [b,g,l,q][5,10,15]triazaporphyrin derivatives

2011 ◽  
Vol 15 (09n10) ◽  
pp. 890-897 ◽  
Author(s):  
Andrew N. Cammidge ◽  
Isabelle Chambrier ◽  
Michael J. Cook ◽  
Ernie H.G. Langner ◽  
Muhibur Rahman ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Bulk Material ◽  
Polarized Light ◽  
Scanning Calorimetry ◽  
Liquid Crystallinity ◽  
Derivatives Of ◽  
Deposited Films

The preparation and characterization of a number of metalated derivatives of 1,4,8,11,15,18,22,25-octahexyl and 1,4,8,11,15,18,22,25-octadecyl tetrabenzotriazaporphyrins (TBTAPs) are reported. The mesophase behavior of the compounds has been characterized by differential scanning calorimetry (DSC) and by polarized light optical microscopy. Mesophase behavior is compared with data for the corresponding phthalocyanine derivatives reported earlier. The temperature range of the mesophase(s) exhibited by the title compounds is generally broader than those of their phthalocyanine analogs. UV-vis data for examples of the TBTAP compounds as spin-coated films reveal differences in the type of molecular packing in the as-deposited films that is largely dependent upon the length of the alkyl chain substituents. On heating, the films undergo molecular reorganizations at temperatures corresponding to the mesophase transitions of bulk material observed by DSC.

scholarly journals THERMAL CHARACTERIZATION OF THE FAVELONE DERIVATIVES (CNIDOSCOLUS QUERCIFOLIUS) BY THERMOGRAVIMETRY AND DIFFERENTIAL SCANNING CALORIMETRY

2006 ◽  
Vol 05 (3) ◽  
pp. 8-20
Author(s):  
José Carlos Oliveira SANTOS ◽  
Lionete Dantas NUNES ◽  
Sylvia Berenice NÓBREGA ◽  
Dantas José Pires PUZINSKI ◽  
Antonio Gouveia SOUZA
Keyword(s):  
Differential Scanning Calorimetry ◽  
Arid Region ◽  
Agricultural Practices ◽  
Thermal Characterization ◽  
Northeastern Brazil ◽  
Scanning Calorimetry ◽  
Semi Arid Region ◽  
Derivatives Of ◽  
Semi Arid

A thermal analysis has been applied to characterization of food and food products. Taking into account the problems of desertification and agricultural practices able to provide income to the population at the semi-arid region of Northeastern Brazil, this work presents the results of the chemical, thermal and kinetic characterization by thermogravimetry and differential scanning calorimetry of the seed derivatives of favelone (cnidoscolus quercifolius), aiming at the application of these materials as an alternative of food source for animals and for the human population at this brazilian region.

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 mesogenic properties of β-tetrabrominated tetraalkyloxyporphyrins

2008 ◽  
Vol 12 (01) ◽  
pp. 54-64 ◽  
Author(s):  
Puttaiah Bhyrappa ◽  
Chellaiah Arunkumar ◽  
Babu Varghese ◽  
Doddamane S. Shankar Rao ◽  
Subbarao K. Prasad
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Scanning Calorimetry ◽  
Point Temperature ◽  
New Class ◽  
Clearing Point

A new class of 2,3,7,8-tetrabromo-5,10,15,20-tetrakis(4'-n-1-alkyloxyphenyl)porphyrins, H 2 T (4'- OC n P ) PBr 4 (n = 4,6,8,10,12,14,16 and 18) and their Cu(II) complexes have been synthesized regioselectively and their mesophase properties explored. The mesogenic properties of the porphyrins were examined by differential scanning calorimetry and optical microscopy. An increase in alkyl chain length of the mesogens, showed an increase in melting point temperature and lowering of their clearing point temperatures with the narrower mesophases. This has been ascribed to the decreased π-π interactions as evidenced from the crystal structure of H 2 T (4'- OC 6 P ) PBr 4· THF derivative. MT (4'- OC n P ) PBr 4 derivatives showed rectangular mesophases in contrast to discotic lamellar mesophases reported for the planar MT (4'- OC n P ) P mesogens.

Synthesis, Electrochemical, and Thermal Properties of [3]Ferrocenophane-Containing Chalcone Derivatives

2015 ◽  
Vol 68 (7) ◽  
pp. 1035 ◽  
Author(s):  
Haiying Zhao ◽  
Xueyou Zhu ◽  
Dong Wang ◽  
Shufeng Chen ◽  
Zhanxi Bian
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Phase Transitions ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Freezing Process ◽  
Naphthalene Ring ◽  
Scanning Calorimetry ◽  
Chalcone Derivatives ◽  
Heating And Cooling

[3]Ferrocenophane-containing chalcone derivatives with benzene ring (3a–3d) or naphthalene ring (3e–3f) were synthesized and characterized. The potentials for [3]ferrocenophane-containing chalcones cathodically shifted ~70–80 mV compared with those of ferrocene-containing chalcones, indicating easier oxidation by loss of an electron for the former. The thermal behaviours of the prepared compounds were studied by differential scanning calorimetry and polarizing optical microscopy. Compound 3f with terminal alkyl chain of 14 carbon atoms displayed mesophases, whereas other compounds were non-mesomorphic and showed either crystal polymorphic phase transitions or simple melting and freezing process in the heating and cooling cycles.

Gelatin and Glycerine-Based Bioadhesive Vaginal Hydrogel

2020 ◽  
Vol 17 (4) ◽  
pp. 303-311
Author(s):  
Roberta Cassano ◽  
Federica Curcio ◽  
Delia Mandracchia ◽  
Adriana Trapani ◽  
Sonia Trombino
Keyword(s):  
Differential Scanning Calorimetry ◽  
Inflammatory Process ◽  
Vaginal Mucosa ◽  
Vaginal Infection ◽  
Scanning Calorimetry ◽  
Time Intervals ◽  
Site Specific ◽  
Release Studies ◽  
Hiv Seropositive

Aim: The work’s aim was the preparation and characterization of a hydrogel based on gelatin and glycerine, useful for site-specific release of benzydamine, an anti-inflammatory drug, able to attenuate the inflammatory process typical of the vaginal infection. Objective: The obtained hydrogel has been characterized by Electronic Scanning Microscopy (SEM) and Differential Scanning Calorimetry (DSC). In addition, due to the precursor properties, the hydrogel exhibits a relevant mucoadhesive activity. Methods: The swelling degree was evaluated at two different pHs and at defined time intervals. In particular, phosphate buffers were used at pH 6.6, in order to mimic the typical conditions of infectious diseases at the vaginal level, particularly for HIV-seropositive pregnant women, and pH 4.6, to simulate the physiological environment. Results: The obtained results revealed that the hydrogel swells up well at both pHs. Conclusion: Release studies conducted at both pathological and physiological pHs have shown that benzydamine is released at the level of the vaginal mucosa in a slow and gradual manner. These data support the hypothesis of the hydrogel use for the site-specific release of benzydamine in the vaginal mucosa.

scholarly journals Identification of LDPE Grades Focusing on Specific CH2 Raman Vibration Modes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Richard Jumeau ◽  
Patrice Bourson ◽  
Michel Ferriol ◽  
François Lahure ◽  
Marc Ponçot ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Vibrational Spectroscopy ◽  
Phenomenological Model ◽  
Low Density ◽  
Vibration Modes ◽  
Scanning Calorimetry ◽  
Lamella Thickness ◽  
Poly Ethylene

The possibilities of applications of vibrational spectroscopy techniques (Raman spectroscopy) in the analysis and characterization of polymers are more and more used and accurate. In this paper, our purpose is to characterize Low Density Poly(Ethylene) (LDPE) grades by Raman spectroscopy and in particular with CH2 Raman vibration modes. With temperature measurements, we determine different amorphous and crystalline Raman assignments. From these results and on the basis of the evolution of CH2 bending Raman vibration modes, we develop a phenomenological model in correlation with Differential Scanning Calorimetry and in particular with crystalline lamella thickness determination.

scholarly journals STRUCTURAL AND MECHANICAL CHARACTERIZATION OF DEFORMED POLYMER USING CONFOCAL RAMAN MICROSCOPY AND DSC

2016 ◽  
Vol 3 ◽  
pp. 47-50
Author(s):  
Birgit Neitzel ◽  
Florian Aschermayer ◽  
Milan Kracalik ◽  
Sabine Hild
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Mechanical Characterization ◽  
Polymer Chains ◽  
Polymer Materials ◽  
Confocal Raman Microscopy ◽  
Micro Structure ◽  
Scanning Calorimetry ◽  
Confocal Raman

Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC) were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.

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