Syntheses and Characterization of Chitosan Oligosaccharide-Graft-Polycaprolactone Copolymer I Thermal and Spherulite Morphology Studies

2011 ◽  
Vol 183-185 ◽  
pp. 155-160 ◽  
Author(s):  
Feng Hong Li ◽  
San Xi Li ◽  
Tao Jiang ◽  
Yong Sun
Keyword(s):  
Ring Opening ◽  
Optical Microscope ◽  
Chitosan Oligosaccharide ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Spherulite Morphology ◽  
Thermal Stable

The thermoplastic graft copolymers of chitosan oligosaccharide (PHCSO-g-PCL) were successfully synthesized via ring-opening polymerization (ROP) of ε-caprolactone (CL) through an amino group protection route using phthaloyl chitosan oligosaccharide (PHCSO) as intermediate. The graft reaction was carried out in Pyridine at 120 °C with a chitosan oligosaccharide (CSO) initiator and a tin 2-ethylhexanoate (Sn (Oct)2) catalyst. The prepared copolymer was characterized by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD). DSC analysis of PHCSO-g-PCL showed higher melting point at 54.8 °C than linear PCL. The TGA analysis showed that PHCSO-g-PCL was more thermal stable than original CSO. The banded spherulite structure of PHCSO-g-PCL and the growth of spherulite were observed by polarized optical microscope (POM); this was further proven by WAXD results.

Synthesis and Characterization of Thermoplastic Biomaterial Based on Acylated Chitosan Oligosaccharide

2011 ◽  
Vol 117-119 ◽  
pp. 1433-1436 ◽  
Author(s):  
Feng Hong Li ◽  
Yong Sun ◽  
San Xi Li ◽  
Shao Jun Ma
Keyword(s):  
Optical Microscope ◽  
Chitosan Oligosaccharide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
X Ray ◽  
Chemical Structures ◽  
Chitosan Oligosaccharides ◽  
Diffraction Peaks

A series of acylated chitosan oligosaccharides (LCSOs) were synthesized by reacting chitosan oligosaccharide (CSO) with lauroyl chloride in methane sulfonic acid. The chemical structures of LCSOs were characterized by Fourier transform infrared. Differential scanning calorimetry (DSC) showed that LCSOs had two phase transitions during heating. Thermoplastic chitosan oligosaccharide (LCSO-4) has distinct melting temperature (Tm) at 64 °C and 110°C. X-ray diffraction (XRD) analyses indicated that the crystal structure of CSO was changed through acylation and had created new crystal domains of lauroyl side chains. New strong diffraction peaks were observed around 2θ values of 20.0°, 21.5° and 26.3° for thermoplastic acylated chitosan oligosaccharide (LCSO-4). The melting and crystallization properties of thermoplastic acylated chitosan oligosaccharide were observed by polarized optical microscope (POM).

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

scholarly journals Stacking Control by Molecular Symmetry of Sterically Protected Phthalocyanines

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5552
Author(s):  
Ryota Kudo ◽  
Masahiro Sonobe ◽  
Yoshiaki Chino ◽  
Yu Kitazawa ◽  
Mutsumi Kimura
Keyword(s):  
Lamellar Structure ◽  
Synthesis And Characterization ◽  
Molecular Symmetry ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Structural Isomers ◽  
X Ray ◽  
Temperature Controlled

The synthesis and characterization of two phthalocyanine (Pc) structural isomers, 1 and 2, in which four 2,6-di(hexyloxy)phenyl units were attached directly to the 1,8,15,22- or 1,4,15,18-positions of the Pc rings, are described. Both Pcs 1 and 2 exhibited low melting points, i.e., 120 and 130 °C respectively, due to the reduction in intermolecular π-π interaction among the Pc rings caused by the steric hindrance of 2,6-dihexyloxybenzene units. The thermal behaviors were investigated with temperature-controlled polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and absorption spectral analyses. Pc 1, having C4h molecular symmetry, organized into a lamellar structure containing lateral assemblies of Pc rings. In contrast, the other Pc 2 revealed the formation of metastable crystalline phases, including disordered stacks of Pcs due to rapid cooling from a melted liquid.

scholarly journals Formation of metal oxide-based hydroxysodalite by alkali-activation of kaolinite

Chemija ◽  
2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Ehab AlShamaileh ◽  
Muayad Esaifan ◽  
Qusay Abu-Afifeh
Keyword(s):  
Activation Energy ◽  
Metal Oxide ◽  
Alkali Activation ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Study ◽  
Dsc Curves

The formation of metal oxide-based hydroxysodalite by alkali-activation of kaolinite is studied using X-ray diffraction (XRD) study and differential scanning calorimetry (DSC) analysis. Different metal oxides (CoO, MgO, FeO and SiO2) were used to form the metal oxide-based hydroxysodalite. The transformation from kaolinite into hydroxysodalite is confirmed by XRD. In the thermodynamic study, the maximum peak temperatures for DSC curves at various heating rates were used to determine the activation energy (Ea) of the hydroxysodalite formation. With magnesium oxide and cobalt oxide, the formation process was found to be exothermic while it was endothermic with iron oxide.

scholarly journals Characterization of the Interface Between the Bulk Glass Forming Alloy Zr41Ti14Cu12Ni10Be23 with Pure Metals and Ceramics

2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson
Keyword(s):  
Sessile Drop ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Processing Times ◽  
Thermal Stability Of

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

scholarly journals Synthesis and Ring-Opening Metathesis Polymerization of a New Norbornene Dicarboximide with a Pendant Carbazole Moiety

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Stefania Pragliola ◽  
Antonio Botta ◽  
Rubina Troiano ◽  
Veronica Paradiso ◽  
Fabia Grisi
Keyword(s):  
Ring Opening ◽  
Microstructural Analysis ◽  
Fluorescence Analysis ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
X Ray ◽  
Excimer Formation ◽  
Film Polymer

A new norbornene dicarboximide presenting a pendant carbazole moiety linked by a p-methylene benzyl spacer is synthesized. This carbazole-functionalized monomer is polymerized via ring-opening metathesis polymerization using Grubbs third-generation catalyst. Microstructural analysis of resulting polymers performed by Nuclear Magnetic Resonance (NMR) shows that they are stereoirregular. Wide-angle X-ray diffraction (WAXD) and thermal (DSC) analysis indicate that polymers are also amorphous. With respect to the fluorescence analysis, both solution and film polymer samples exhibit only “normal structured” carbazole fluorescence, while excimer formation by overlap of carbazole groups is not detected.

scholarly journals The Preparation and Characterization of Polyacrylonitrile-Polyaniline (PAN/PANI) Fibers

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 664 ◽  
Author(s):  
Iwona Karbownik ◽  
Olga Rac-Rumijowska ◽  
Marta Fiedot-Toboła ◽  
Tomasz Rybicki ◽  
Helena Teterycz
Keyword(s):  
Specific Resistance ◽  
Strong Interactions ◽  
Mechanical Parameters ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Strength Tests ◽  
Pan Fibers

The paper presents a method of modifying polyacrylonitrile (PAN) fibers using polyaniline (PANI). The PAN fibers were doped with polyaniline that was obtained in two different ways. The first consisted of doping a spinning solution with polyaniline that was synthesized in an aqueous solution (PAN/PANI blended), and the second involved the synthesis of polyaniline directly in the spinning solution (PAN/PANI in situ). The obtained fibers were characterized by the methods: X-ray powder diffraction (XRD), scanning electron microscope (SEM), fourier-transform infrared spectroscopy (FTIR), thermogravimetry (TG) and differential scanning calorimetry (DSC). Analysis of the results showed strong interactions between the nitrile groups of polyacrylonitrile and polyaniline in the PAN/PANI in situ fibers. The results of mechanical strength tests indicated that the performance of the PAN/PANI mixture significantly improved the mechanical parameters of polyaniline, although these fibers had a weaker strength than the unmodified PAN fibers. The fibers obtained as a result of the addition of PANI to PAN were dielectric, whereas the PANI-synthesized in situ were characterized by a mass-specific resistance of 5.47 kΩg/cm2.

The Synthesis and Characterization of Oxide Free Tin Nanoparticles

2014 ◽  
Vol 670-671 ◽  
pp. 26-29
Author(s):  
Zhi Long Pan ◽  
Shi Liang Ao ◽  
Jian Ping Jia
Keyword(s):  
Reduction Method ◽  
Chemical Reduction ◽  
Thermal Characterization ◽  
X Ray Diffraction ◽  
Chemical Reduction Method ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Study ◽  
Tin Nanoparticles

Oxide free Tin nanoparticles were synthesized from a chemical reduction method. Their morphological and thermal characterizations were studied in this paper. The X-ray diffraction (XRD) study showed that no oxides of Tin nanoparticles were formed. The thermal characterization by differential scanning calorimetry (DSC) exhibited the size dependency of the melting points. The melting point was as low as 202.16°C.

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