scholarly journals Hybrid Electromagnetic Nanomaterials Based on Polydiphenylamine-2-carboxylic Acid

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1568
Author(s):  
Sveta Zhiraslanovna Ozkan ◽  
Aleksandr Ivanovich Kostev ◽  
Galina Petrovna Karpacheva ◽  
Petr Aleksandrovich Chernavskii ◽  
Andrey Aleksandrovich Vasilev ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Alkaline Medium ◽  
Acidic Medium ◽  
Oxidative Polymerization ◽  
Reaction Medium ◽  
Medium Ph ◽  
Extraction And Purification ◽  
Structure Morphology ◽  
Polymer Metal ◽  
Walled Carbon Nanotubes

Hybrid ternary nanomaterials based on conjugated polymer polydiphenylamine-2-carboxylic acid (PDPAC) (poly-N-phenylanthranilic acid), Fe3O4 nanoparticles and single-walled carbon nanotubes (SWCNT) were prepared for the first time. Polymer–metal–carbon Fe3O4/SWCNT/PDPAC nanocomposites were synthesized via in situ oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) by two different ways: in an acidic medium and in the interfacial process in an alkaline medium. In an alkaline medium (pH 11.4), the entire process of Fe3O4/SWCNT/PDPAC-1 synthesis was carried out in one reaction vessel without intermediate stages of product extraction and purification. In an acidic medium (pH 0.3), to prepare the Fe3O4/SWCNT/PDPAC-2 nanocomposites, prefabricated magnetite nanoparticles were deposited on the surface of obtained SWCNT/PDPAC-2. The phase composition of the nanocomposites does not depend on the synthesis reaction medium pH. The influence of the reaction medium pH on the structure, morphology, thermal, magnetic, and electrical properties of the obtained ternary nanocomposites was studied.

scholarly journals Formation Features of Hybrid Nanocomposites Based on Polydiphenylamine-2-Carboxylic Acid and Single-Walled Carbon Nanotubes

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1181 ◽  
Author(s):  
Sveta Zhiraslanovna Ozkan ◽  
Galina Petrovna Karpacheva ◽  
Aleksandr Ivanovich Kostev ◽  
Galina Nikolaevna Bondarenko
Keyword(s):  
Carbon Nanotubes ◽  
Carboxylic Acid ◽  
Carbon Nanomaterials ◽  
Oxidative Polymerization ◽  
Ammonium Hydroxide ◽  
Single Walled Carbon Nanotubes ◽  
Hybrid Nanocomposites ◽  
Heterophase System ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Hybrid nanocomposites based on electroactive polydiphenylamine-2-carboxylic acid (PDPAC) and single-walled carbon nanotubes (SWCNTs) were obtained for the first time. Polymer-carbon nanomaterials were synthesized via in situ oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) in the presence of SWCNTs by two different ways. Hybrid SWCNT/PDPAC nanocomposites were prepared both in an acidic medium and in the heterophase system in an alkaline medium. In the heterophase system, the monomer and the SWCNTs are in the organic phase (chloroform) and the oxidant (ammonium persulfate) is in an aqueous solution of ammonium hydroxide. The chemical structure, as well as the electrical and thermal properties of the developed SWCNT/PDPAC nanocomposite materials were investigated.

Reactions of some 2-(6-azauracil-5-yl)phenylhydrazones

1979 ◽  
Vol 44 (8) ◽  
pp. 2438-2442 ◽  
Author(s):  
Jan Slouka
Keyword(s):  
Carboxylic Acid ◽  
Acid Medium ◽  
Alkaline Medium ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Azo Coupling

Azo coupling of the diazotized 6-(2-aminophenyl)-2,3,4,5-tetrahydro-1,2,4-triazine-3,5-dione with ethyl cyanoacetylcarbamate and diethyl malonyl-bis-carbamate has been used for preparation of the hydrazones I and II. The latter substances have been boiled in strongly acidic medium to give 2,3,4,6-tetrahydro-1,2,4-triazino[5,6-c]cinnoline-3-one (III) which has also been obtained by reduction of the mentioned diazonium salt with alkali sulphite and sebsequent cyclization of the formed hydrazine sulphonate by boiling in acid medium. In alkaline medium the hydrazones I and II have been cyclized to the nitrile IV and to 2-[2-(3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazin-6-yl)-phenyl]-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxylic acid (V), respectively.

scholarly journals Nanostructured LiFe5O8 by a Biogenic Method for Applications from Electronics to Medicine

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 193
Author(s):  
Silvia Soreto Teixeira ◽  
Manuel P. F. Graça ◽  
José Lucas ◽  
Manuel Almeida Valente ◽  
Paula I. P. Soares ◽  
...  
Keyword(s):  
Spinel Ferrite ◽  
Sol Gel ◽  
Reaction Medium ◽  
Magnetic Hyperthermia ◽  
Magnetic Characteristics ◽  
Secondary Phases ◽  
Heat Treated ◽  
Structure Morphology ◽  
Sol Gel Process ◽  
Crystallite Sizes

The physical properties of the cubic and ferrimagnetic spinel ferrite LiFe5O8 has made it an attractive material for electronic and medical applications. In this work, LiFe5O8 nanosized crystallites were synthesized by a novel and eco-friendly sol-gel process, by using powder coconut water as a mediated reaction medium. The dried powders were heat-treated (HT) at temperatures between 400 and 1000 °C, and their structure, morphology, electrical and magnetic characteristics, cytotoxicity, and magnetic hyperthermia assays were performed. The heat treatment of the LiFe5O8 powder tunes the crystallite sizes between 50 nm and 200 nm. When increasing the temperature of the HT, secondary phases start to form. The dielectric analysis revealed, at 300 K and 10 kHz, an increase of ε′ (≈10 up to ≈14) with a tanδ almost constant (≈0.3) with the increase of the HT temperature. The cytotoxicity results reveal, for concentrations below 2.5 mg/mL, that all samples have a non-cytotoxicity property. The sample heat-treated at 1000 °C, which revealed hysteresis and magnetic saturation of 73 emu g−1 at 300 K, showed a heating profile adequate for magnetic hyperthermia applications, showing the potential for biomedical applications.

Iron and nitrogen co-functionalized porous 3D graphene frameworks as an efficient oxygen reduction catalyst

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74886-74894 ◽  
Author(s):  
Lili Cui ◽  
Mei Wu ◽  
Jinbao Xiang
Keyword(s):  
Oxygen Reduction ◽  
Alkaline Medium ◽  
Electrocatalytic Activity ◽  
Acidic Medium ◽  
3D Graphene ◽  
Enhanced Activity ◽  
Oxygen Reduction Catalyst

Fe/N-GAs exhibit comparable electrocatalytic activity to commercial Pt/C in alkaline medium together with enhanced activity compared to N-GAs in acidic medium.

scholarly journals Estimation of ethylene production and 1-aminocyclopropane-1-carboxylic acid in plants by means of gas chromatography

2008 ◽  
Vol 54 (No. 2) ◽  
pp. 55-60 ◽  
Author(s):  
H. Fišerová ◽  
Z. Mikušová ◽  
M. Klemš
Keyword(s):  
Gas Chromatography ◽  
Carboxylic Acid ◽  
Ethylene Production ◽  
Sampling Procedure ◽  
Alternative Methods ◽  
Time Consumption ◽  
Advantages And Disadvantages ◽  
Endogenous Level ◽  
Extraction And Purification ◽  
And Storage

The paper deals with problems associated with preparation and collection of samples when estimating the production of ethylene and content of ACC (1-aminocyclopropane-1-carboxylic acid) in plants by means of gas chromatography. A proper method of sampling can significantly influence not only the reliability of obtained data but also their interpretation. Attention was paid to cultivation of plant material, sampling vessels, conditions of ethylene production, sampling procedure, and storage of gaseous samples. The estimation of ACC as a precursor of ethylene is more laborious but it supplements the information about the endogenous level of ethylene in a given part of the plant organism. The authors describe the sampling procedure, methods of sample preservation, extraction and purification, and also the method of oxidation of ACC to ethylene. In the final part of this study the authors evaluate the time consumption and difficulty of individual methods and describe their advantages and disadvantages as compared with other, alternative methods.

Sidewall Carboxylic Acid Functionalization of Single-Walled Carbon Nanotubes

2003 ◽  
Vol 125 (49) ◽  
pp. 15174-15182 ◽  
Author(s):  
Haiqing Peng ◽  
Lawrence B. Alemany ◽  
John L. Margrave ◽  
Valery N. Khabashesku
Keyword(s):  
Carbon Nanotubes ◽  
Carboxylic Acid ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes
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