Fabrication of Superconducting Bi-Sr-Ca-Cu-O Oxide Films Using the Metal Alkoxide Method

1990 ◽  
Vol 180 ◽  
Author(s):  
Shingo Katayama ◽  
Masahiro Sekine
Keyword(s):  
Oxide Films ◽  
Superconducting Films ◽  
Dip Coating ◽  
Metal Alkoxide ◽  
Nominal Composition ◽  
Metal Alkoxides ◽  
Coating Solution ◽  
H Nmr ◽  
Ft Ir ◽  
Alkoxide Method

ABSTRACTSuperconducting films in the Bi-Sr-Ca-Cu-O system were fabricated using metal alkoxides. To make a mixed alkoxide solution into a dip-coating solution, insoluble Cu alkoxide was modified with 2-dimethylaminoethanol and insoluble Bi alkoxide was dissolved in the presence of Ca and/or Sr alkoxides. The structures of these alkoxide derivatives were studied by FT-IR, 1 H-NMR, and EXAFS. The film with Tc(zero)=115K was fabricated using the alkoxide solution with a nominal composition of Bi:Sr:Ca:Cu=2:2:3:4.

Bi–Sr–Ca–Cu–O superconducting films fabricated using metal alkoxides

1991 ◽  
Vol 6 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Shingo Katayama ◽  
Masahiro Sekine
Keyword(s):  
Single Crystal ◽  
Superconducting Films ◽  
Dip Coating ◽  
Metal Alkoxides ◽  
Coating Solution ◽  
H Nmr ◽  
Zero Resistance ◽  
Ft Ir

Superconducting films in the Bi–Sr–Ca–Cu–O systems were made using metal alkoxides. To prepare a dip-coating solution using a mixed alkoxide solution, insoluble Cu and Bi alkoxides were dissolved by modification with 2-dimethylaminoethanol and formation of a double alkoxide, respectively. Formation of the double alkoxides of Bi with Ca or Sr was confirmed using FT-IR and 1H-NMR. Bi–Sr–Ca–Cu–O films on yttria-stabilized ZrO2 and single crystal MgO(100) substrates were made using this solution. The films were closely oriented along the c-axis perpendicular to the substrate. The film on MgO(100) fired at 850 °C for 48 h showed two resistance drops around 115 and 85 K, corresponding to the high-Tc and low-Tc phases, respectively, and zero resistance at 72 K.

Superconducting oxide YBa2Cu3O7−x prepared by the metal alkoxide method

1990 ◽  
Vol 5 (4) ◽  
pp. 683-690 ◽  
Author(s):  
Shingo Katayama ◽  
Masahiro Sekine
Keyword(s):  
Single Phase ◽  
Homogeneous Solution ◽  
Metal Alkoxide ◽  
H Nmr ◽  
Present Solution ◽  
Interchange Reaction ◽  
Yttrium Barium ◽  
Ft Ir ◽  
Alkoxide Method ◽  
Hydrolysis Of

Preparation of the superconducting oxide, YBa2Cu3O7−x, was carried out according to the metal alkoxide method. To obtain a homogeneous solution of yttrium, barium, and copper alkoxide in an organic solvent, alkoxides of copper and yttrium were modified by the O-R interchange reaction with 2-dimethylaminoethanol and the structures of their modified alkoxides were studied by 1H-NMR, FT-IR, and EXAFS. The YBa2Cu3O7−x precursor, prepared by hydrolysis of the present solution of alkoxides, was calcined at 850°C for 3 h to give YBa2Cu3O7−x powder as a single phase. This powder was sintered between 900°C and 950°C and characterized for bulk density, microstructure, Tc, and Jc.

Porous Gel Coatings Obtained by Phase Separation in ORMOSIL System

2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai
Keyword(s):  
Phase Separation ◽  
Reaction Time ◽  
Volume Fraction ◽  
Sol Gel ◽  
Reaction Times ◽  
Dip Coating ◽  
Coating Solution ◽  
Coating Method ◽  
Gel Phase ◽  
Dip Coating Method

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.

scholarly journals Synthesis and antioxidant properties of 2-(3-(hydroxyimino)methyl)-1H-indol-1-yl)acetamide derivatives

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Chandravadivelu Gopi ◽  
Magharla Dasaratha Dhanaraju
Keyword(s):  
Antioxidant Activity ◽  
Condensation Reaction ◽  
Antioxidant Properties ◽  
Side Chain ◽  
Antioxidant Power ◽  
H Nmr ◽  
Antioxidant Agents ◽  
Phenyl Rings ◽  
Ferric Reducing Antioxidant Power ◽  
Ft Ir

Abstract Background The main aim of this work was to synthesise a novel N-(substituted phenyl)-2-(3-(hydroxyimino) methyl)-1H-indol-1-yl) acetamide derivatives and evaluate their antioxidant activity. These compounds were prepared by a condensation reaction between 1H-indole carbaldehyde oxime and 2-chloro acetamide derivatives. The newly synthesised compound structures were characterised by FT-IR, 1H-NMR, mass spectroscopy and elemental analysis. Furthermore, the above-mentioned compounds were screened for antioxidant activity by using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods. Result The antioxidant activity result reveals that most of the compounds were exhibiting considerable activity in both methods and the values are very closer to the standards. Among the synthesised compounds, compound 3j, 3a and 3k were shown remarkable activity at low concentration. Conclusion Compounds 3j, 3a and 3k were shown highest activity among the prepared analogues due to the attachment of halogens connected at the appropriate place in the phenyl ring. Hence, these substituted phenyl rings considered as a perfect side chain for the indole nucleus for the development of the new antioxidant agents.

Ultrasound-assisted aqua-mediated synthesis of multi-substituted tetrahydropyridine-3-carboxylates using N-carboxymethyl-3-pyridinium hydrogensulfate ([N-CH2CO2H-3-pic]+HSO4−) as a new efficient ionic liquid catalyst

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Environmentally Benign ◽  
H Nmr ◽  
Sonic Waves ◽  
Ft Ir ◽  
High Yields ◽  
Work Up ◽  
C Nmr

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

1H-NMR Analysis of Degree of Substitution in N,O-Carboxymethyl Chitosans from Various Chitosan Sources and Types

2012 ◽  
Vol 506 ◽  
pp. 158-161 ◽  
Author(s):  
A. Jaidee ◽  
Pornchai Rachtanapun ◽  
S. Luangkamin
Keyword(s):  
Chemical Structure ◽  
Carboxymethyl Chitosan ◽  
Degree Of Substitution ◽  
Resonance Spectroscopy ◽  
Nmr Analysis ◽  
Reaction Conditions ◽  
H Nmr ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Chitosan Oligomer ◽  
Ft Ir

N,O-Carboxymethyl chitosans were synthesized by the reaction between shrimp, crab and squid chitosans with monochloroacetic acid under basic conditions at 50°C. The mole ratio of reactants was obtained from various reaction conditions of shrimp chitosan polymer and oligomer types. The mole ratio 1:12:6 of chitosan:sodium hydroxide:monochloroacetic acid was used for preparing carboxymethyl of chitosan polymer types while carboxymethyl of chitosan oligomer types were used the mole ratio 1:6:3 of chitosan:sodium hydroxide:monochloroacetic acid. The chemical structure was analyzed by fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnatic resonance spectroscopy (1H-NMR). The FT-IR was used for confirm the insertion of carboxymethyl group on chitosan molecules. The 1H-NMR was used for determining the degree of substitution (DS) of carboxymethylation at hydroxyl and amino sites of chitosans. Carboxymethyl chitosan samples had the total DS of carboxymethylation ranging from 1.0-2.2. The highest of DS of carboxymethylation was from shrimp chitosan oligomer type.

scholarly journals Synthesis, Characterization, and Antimicrobial Activity of Methyl-2-aminopyridine-4-carboxylate Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
S. Nagashree ◽  
P. Mallu ◽  
L. Mallesha ◽  
S. Bindya
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Studies ◽  
H Nmr ◽  
Chemical Structures ◽  
Elemental Analyses ◽  
Ft Ir

A series of methyl-2-aminopyridine-4-carboxylate derivatives,3a–f,were synthesized in order to determine theirin vitroantimicrobial activity. The chemical structures of the synthesized compounds were confirmed by elemental analyses, FT-IR, and1H NMR spectral studies. Among the synthesized compounds,3cand3dshowed good antimicrobial activity compared to other compounds in the series.

Synthesis of biomass based plasticizer from linoleic acid and cardanol for preparing durable PVC material

2021 ◽  
Author(s):  
Hongying Chu ◽  
Huabei Li ◽  
Xiaoyan Sun ◽  
Yaowang Zhang
Keyword(s):  
Thermal Stability ◽  
Linoleic Acid ◽  
Chemical Structure ◽  
Dioctyl Phthalate ◽  
H Nmr ◽  
Plasticized Pvc ◽  
Migration Resistance ◽  
Ft Ir ◽  
And Migration ◽  
Thermal Stability Of

Abstract In this paper, we synthesized a kind of bio-based plasticizer epoxidized linoleic acid cardanol ester(ELCE) from cardanol and linoleic acid. Its chemical structure was characterized with FT-IR and 1H NMR. Polyvinyl chloride(PVC) blends plasticized with ELCE were prepared via thermoplastic blending with torque rheometer. The performance including torque, mechanical property, thermal stability, plasticizing property and migration resistance of plasticized PVC blends were investigated and compared with plasticized PVC blends with commercial plasticizer dioctyl phthalate(DOP). The results showed that ELCE improved thermal stability of PVC blends. ELCE played more excellent plasticizing effect on PVC blends than DOP. The better solvent extraction resistance and volatile resistance of ELCE make it impossible to completely replace DOP in PVC products.

Synthesis, Characterization and Solution Properties of Novel Cationic Ester-Based Gemini Surfactants

2019 ◽  
Vol 233 (5) ◽  
pp. 707-720 ◽  
Author(s):  
Manorama Panda ◽  
Nazish Fatma ◽  
Mohammad Kamil
Keyword(s):  
Gemini Surfactants ◽  
Alkyl Chain ◽  
Solution Properties ◽  
H Nmr ◽  
Surfactant Solutions ◽  
Cationic Gemini Surfactants ◽  
Ft Ir ◽  
M 12 ◽  
Dimeric Surfactant ◽  
Ft Ir Spectroscopy

Abstract The present investigation involves the synthesis of a series of novel green ethylene oxide-linked diester-functionalized cationic gemini surfactants 2,2′-[(oxybis(ethane-1,2-diyl))bis(oxy)]bis(N-alkyl-N,N-dimethyl-2-oxoethanaminium) dichloride (Cm-DEG-Cm; m = 12, 14, 16). These compounds were characterized by 1H-NMR, MS-ESI (+), FT-IR spectroscopy and elemental analysis; their solution properties were evaluated by surface tension and rheology measurements. The dimeric surfactant, Cm-DEG-Cm, possesses improved physicochemical properties as compared to its monomeric counterpart. Much lower critical micelle concentration (cmc) makes the cationic gemini surfactants more useful for the biomedical, pharmaceutical, industrial and academic sectors. Longer the alkyl chain of surfactants lower are the cmc values, the order is C16-DEG-C16 < C14-DEG-C14 < C12-DEG-C12. For all the three synthesized gemini surfactants no cloud point was noticed in between the temperatures 0 °C to 100 °C at the concentrations 0.002 mM, 0.02 mM and 0.2 mM of the aqueous surfactant solutions which is a beneficial factor for the use of these amphiphiles in various areas of application.

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