Preparation and Characterization of Y3Al5O12 (YAG) from An Alkoxide-Derived Polymer

1992 ◽  
Vol 286 ◽  
Author(s):  
Zhiping Jiang ◽  
Wendell E. Rhine
Keyword(s):  
Infrared Spectroscopy ◽  
Yttrium Aluminum Garnet ◽  
Polymeric Materials ◽  
Pyrolysis Products ◽  
Elemental Analyses ◽  
Yttrium Aluminum ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

ABSTRACTThe controlled hydrolysis of Al(O-sec-Bu)3 and Y(O-iso-Pr)3 or the reaction of Y(OOCCH)3 with partially hydrolyzed Al(O-sec-Bu)3 [AlO0.75(O-sec-Bu)1.5] resulted in the formation of soluble polymeric materials. Pyrolysis of these materials under a flow of oxygen led to the formation of yttrium aluminum garnet (YAG) at 650-1500°C. YAG was the only crystalline phase observed during pyrolysis, and the Al/Y ratio of the pyrolysis products and the starting material was identical. However, infrared spectroscopy indicated that carbonate groups and entrained CO2 existed in the products at temperatures up to 1250°C. The pyrolysis chemistry of the precursors and the microstructure of the products were studied by FT-IR, TGA, XRD, SEM and elemental analyses.

Hyphenated On-The-Spot TG/FT-IR Technique

1992 ◽  
Vol 46 (1) ◽  
pp. 88-92 ◽  
Author(s):  
J. A. J. Jansen ◽  
J. H. Van Der Maas ◽  
A. Posthuma De Boer
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermal Behavior ◽  
Condensed Phase ◽  
Direct Detection ◽  
Polymeric Materials ◽  
Experimental Setup ◽  
Ir Detector ◽  
Ft Ir

By the coupling of thermogravimetry (TG) and Fourier transform infrared spectroscopy (FT-IR), the thermal behavior of polymeric materials can be elucidated from their mass loss combined with characterization of the evolved components. A hyphenated TG/FT-IR technique is presented, which enables the direct detection and characterization of evolving components in TG experiments, i.e., without transferring these components from the TG to the FT-IR equipment. In this on-the-spot TG/FT-IR technique, the IR beam of the FT-IR spectrometer is led directly into the TG equipment. The IR beam is reflected by a mirror mounted inside the TG equipment and subsequently detected by a standard FT-IR detector. In this way, the evolved components are detected both in gas and condensed phase directly in the TG equipment. The detection limits are in the sub µg/s range. The experimental setup and conditions are presented together with advantages and applications in the field of polymeric research.

scholarly journals Characterization of Glycoside Hydrolase Family 5 Proteins in Schizosaccharomyces pombe

2010 ◽  
Vol 9 (11) ◽  
pp. 1650-1660 ◽  
Author(s):  
Encarnación Dueñas-Santero ◽  
Ana Belén Martín-Cuadrado ◽  
Thierry Fontaine ◽  
Jean-Paul Latgé ◽  
Francisco del Rey ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Protein Characterization ◽  
Wall Material ◽  
Glycoside Hydrolase Family ◽  
Content Type ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis ◽  
Hydrolase Family

ABSTRACT In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1 + (locus SPBC1105.05), exg2 + (SPAC12B10.11), and exg3 + (SPBC2D10.05). The three proteins have different localizations: Exg1 is secreted to the periplasmic space, Exg2 is a membrane protein, and Exg3 is a cytoplasmic protein. Characterization of the biochemical activity of the proteins indicated that Exg1 and Exg3 are active only against β(1,6)-glucans while no activity was detected for Exg2. Interestingly, Exg1 cleaves the glucans with an endohydrolytic mode of action. exg1 + showed periodic expression during the cell cycle, with a maximum coinciding with the septation process, and its expression was dependent on the transcription factor Sep1. The Exg1 protein localizes to the septum region in a pattern that was different from that of the endo-β(1,3)-glucanase Eng1. Overexpression of Exg2 resulted in an increase in cell wall material at the poles and in the septum, but the putative catalytic activity of the protein was not required for this effect.

Characterization of Catalytic Supports by Infrared Spectroscopy and ESCA

1982 ◽  
Vol 36 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Larry F. Wieserman ◽  
David M. Hercules
Keyword(s):  
Infrared Spectroscopy ◽  
Surface Area ◽  
Elevated Temperatures ◽  
Silica Alumina ◽  
Free Hydroxyl ◽  
Ft Ir ◽  
Catalytic Supports ◽  
Silica And Titania

This study compares the properties of γ-alumina, silica, and titania using ESCA and in situ FT-IR. The FWHM's of the O1s and metal 2p ESCA peaks increased systematically from titania to γ alumina; the O1s/metal 2p ESCA peak area ratios were nearly equal for γ-alumina and silica. For titania, however, the value was half that obtained for γ-alumina. In situ FT-IR showed hydroxyl bands with increasing frequencies from titania to silica. Alumina and titania form carbonate-type structures after exposure to CO at elevated temperatures. Silica exhibited no additional bands after CO treatment that could be assigned to physically adsorbed CO or carbonate-type structures. At 100°C, there is a direct correlation between the specific surface area and the intensity of infrared absorbance of the free-hydroxyl and the hydrogen-bonded hydroxyl bands for silica. The intensities of the infrared bands due to matrix modes were not affected by surface area.

scholarly journals Synthesis and Characterization of Trivalent Cerium Complexes of p-tert-Butylcalix[4,6,8]Arenes: Effect of Organic Solvents

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Md. Hasan Zahir
Keyword(s):  
Organic Solvents ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
H Nmr ◽  
Protic Solvents ◽  
Elemental Analyses ◽  
Ft Ir ◽  
X Ray Absorption ◽  
Molar Extinction Coefficients

Reaction of Ce3+with p-tert-butylcalix[n]arene (n=4,6,8) yields purple crystalline complexes structurally as [Ce(p-tert-butylcalix[4]arene-3H)2(NO3)(DMF)x](2 −x)DMF (1), [Ce(p-tert-butylcalix[6]arene-4H)2(NO3)(DMF)x](3 −x)DMF (2), and [Ce(p-tert-butylcalix[8]arene-7H)2(NO3)(DMF)6] (3), whereDMF=N,N-dimethylformamide. The properties and coordination characteristics of the three calixarene complexes were determined by elemental analyses, electronic absorption, X-ray absorption spectroscopy (EXAFS), TG-DTA, FT-IR, SEM, and1H-NMR spectroscopy. The effect of various organic solvents on complexes1,2, and3has been discussed based on results from electronic absorption spectra. The polar protic solvents showed the most significant molar extinction coefficients in comparison with those of nonpolar and polar aprotic solvents. The Ce3+ions in the complexes are proved to combine with the ligand phenolic groups, oxygen atoms of DMF molecules, and/or OH−ions.

The Preparation and Characterization of the Solid Acid Catalyst for the Esterification of the Gutter Oil

2014 ◽  
Vol 881-883 ◽  
pp. 297-301 ◽  
Author(s):  
Yan Zhi Liu ◽  
Shun Ping Wang ◽  
Kun Yuan ◽  
Huian Tang
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Active Carbon ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Raw Material ◽  
Ft Ir

The solid acid catalyst (ACSA) for the gutter oil esterification to biodiesel was prepared via active carbon as raw material by introducing the-SO3H group onto the surface of it. The ACSA were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and elemental analysis (EA), respectively. And the results showed that the-SO3H groups were successfully introduced onto the surface of the active carbon and the containing of the-SO3H groups are higher than 0.017g per gram of ACSA.

Preparation and Characterization of Sic From Alkoxide-Derived Polymeric Precursors

1991 ◽  
Vol 249 ◽  
Author(s):  
Zhiping Jiang ◽  
Wendell E. Rhine
Keyword(s):  
Carbothermic Reduction ◽  
Pyrolysis Products ◽  
Polymeric Precursors ◽  
Polyfurfuryl Alcohol ◽  
Elemental Analyses ◽  
Molecular Source

ABSTRACTCrystalline SiC was prepared by carbothermic reduction of alkoxide-derived polymeric precursors under a flow of argon at 1400-1600°C. The pyrolysis products from the precursors with a molecular source of carbon, i.e., (R1)x(R2)ySiO1.5(Rl=phenyl; R2=propyl, vinyl), showed different morphologies from those of the precursors derived from TEOS and a polymeric source of carbon (polyfurfuryl alcohol). Furthermore, the pyrolysis chemistry of theses precursors and the microstructure of their corresponding pyrolysis products were studied by means of FTIR, TGA, XRD, SEM, BET, elemental analyses, etc.

Preparation and Characterization of Heparin-Immobilized Poly(Ether Urethanes)

2011 ◽  
Vol 393-395 ◽  
pp. 236-239
Author(s):  
Li Ming Lian ◽  
Bing Leng ◽  
Xiao Hua Ma
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Aqueous Solutions ◽  
Fourier Transform Infrared Spectroscopy ◽  
Toluidine Blue ◽  
Water Contact ◽  
The Fourier Transform ◽  
Hydrolysis Of

Heparin (Hep)-immobilized poly(ether urethanes) (PU) was prepared by a unique preparation procedure. Firstly, the poly(ether urethanes)(PU) containing diester groups in the side chains were synthesized. Then, PU was dispersed in aqueous solutions and immobilized with heparin after the hydrolysis of diester groups and carboxylation. The Fourier transform infrared spectroscopy (FTIR) and water contact angle (WCA) were used to characterize the heparin-bonded PU. The amount of heparin grafted on the PU was determined to be 0.57wt.% by the toluidine blue method. The heparin-immobilized PU could release just 12% of the immobilized heparin in the early 10 hours of the 70 hours immobilized heparin stability test.

Characterization of Electron Beam Irradiated Polyvinylpyrrolidone-Dextran (PVP/DEX) Blends

2012 ◽  
Vol 188 ◽  
pp. 102-108 ◽  
Author(s):  
Maria Dumitraşcu ◽  
Mădălina Georgiana Albu ◽  
Marian Vîrgolici ◽  
Cătălin Vancea ◽  
Viorica Meltzer
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Polymeric Materials ◽  
Beam Irradiation ◽  
Molecular Weights ◽  
The Past ◽  
Polymeric Blends ◽  
Irradiation Treatment ◽  
Ft Ir

In the past years an increased interest to create new polymeric blends with application in the medical area for development of new types of biomaterials has appeared. Electron beam irradiation is well known as a method of producing important changes in polymer structure, being an alternative to chemical synthesis of biomaterials based on polymeric materials. The aim of the present study was to investigate the behaviour of some polyvinylpyrrolidone-dextran (PVP/DEX) blends under electron beam irradiation. Aqueous solutions of PVP with molecular weights of 360 000 Da (PVP 360), 40 000 Da (PVP 40), and DEX with molecular weight of 500 000 Da (DEX), were mixed as to obtain 50:50 blends of PVP40/DEX and PVP360/DEX. The obtained blends were irradiated with electron beam at different radiation doses and after irradiation treatment were processed by freeze-drying. PVP/DEX blends were characterized by infrared spectroscopy (FT-IR) and thermal analysis. The analyses were conducted in order to establish the relation between radiation dose and changes of structural and thermal properties.

Synthesis and Structural Characterization of a Series of Group 11 2,2-Dialkyl-1,3-dicyclohexylguanidinate Complexes

2014 ◽  
Vol 67 (7) ◽  
pp. 1021 ◽  
Author(s):  
Sonya K. Adas ◽  
Jesus A. Ocana ◽  
Scott D. Bunge
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
7Li Nmr ◽  
Elemental Analyses ◽  
Lithium Diethylamide ◽  
Structural Aspects

The addition of either lithium dimethylamide or lithium diethylamide to a tetrahydrofuran (THF) solution of 1,3-dicyclohexylcarbodiimide yielded THF adducts of lithium 2,2-dimethyl-1,3-dicyclohexylguandidinate (1) and lithium 2,2-diethyl-1,3-dicyclohexylguandidinate (2), respectively. One equivalent of either 1 or 2 was subsequently reacted with one equivalent of Group 11 halide (CuCl, AgBr, and AuCl) to generate oligonuclear complexes with the general formula {M[CyNC(NR2)NCy]}n where M, R, and n are respectively Cu, CH3, 2 (3); Cu, CH2CH3, 2 (4); Ag, CH3, 3 (5); Ag, CH2CH3, 3 (6); Au, CH3, 2 (7); and Au, CH2CH3, 2 (8). Compounds 1–8 were characterized by single-crystal X-ray diffraction. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, Fourier transform infrared spectroscopy, and 1H, 13C, and 7Li NMR studies. The unique structural aspects of this family of Group 11 complexes are highlighted.

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