scholarly journals Observation of Concentration Diffusion Behavior of Hydrazine Hydrate

2019 ◽  
Vol 33 (1) ◽  
pp. 71-76
Author(s):  
Hiroki TAKIGUCHI ◽  
Masahiro FURUYA ◽  
Takahiro ARAI
Keyword(s):  
Hydrazine Hydrate ◽  
Diffusion Behavior ◽  
Concentration Diffusion

Synthesis and Antibacterial Screening of Some Pyrazole Derivatives Catalyzed by Cetyltrimethylammoniumbromide (CTAB)

2020 ◽  
Vol 17 ◽  
Author(s):  
Ravi Bansal ◽  
Pradeep K. Soni ◽  
Neha Gupta ◽  
Sameer S. Bhagyawant ◽  
Anand K. Halve
Keyword(s):  
Hydrazine Hydrate ◽  
Ethyl Acetoacetate ◽  
Aromatic Aldehydes ◽  
Pyrazole Derivatives ◽  
Phenyl Hydrazine ◽  
One Pot ◽  
Antibacterial Screening ◽  
Water As Solvent ◽  
Substituted Pyrazoles ◽  
Sulfinic Esters

Aims: In this article we have developed an eco-friendly one-pot multi-component reaction methodology was employed for the green synthesis of functionalized pyrazole derivatives viz cyclo-condensation of aromatic aldehydes, ethyl acetoacetate and phenyl hydrazine and/or hydrazine hydrate in the presence of cetyltrimethylammoniumbromide (CTAB) at 90°C temperature in aqueous medium. Method: In the present protocol we developed a green method for the synthesis of functionalized pyrazole derivatives through one-pot, multi-component cyclo-condensation of aromatic aldehydes, phenyl hydrazine or hydrazine hydrate and ethyl acetoacetate using cetyltrimethylammoniumbromide (CTAB) as a catalyst in water as solvent. Our methodology confers advantages such as short reaction time, atom economy, purification of product without using column chromatographic and hazardous solvent. The reaction is being catalyzed by cetyltrimethylammoniumbromide (CTAB) and thus products are formed under the green reaction conditions. Results: Initially the reaction of benzaldehyde and phenylhydrazine with ethyl acetoacetate was carried out in water at room temperature in the absence of the catalyst; no product was obtained after 24 h (Table 1 entry 1). When the reaction was carried out using L-proline as catalyst in ethanol at 70°C the yield of product was 20. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. We consider that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in future. In conclusion, we have developed successfully a green and efficient one-pot multi-component methodology for the synthesis of substituted pyrazoles using CTAB as a catalyst in water as solvent with excellent yields. Purifications of compounds were achieved without the use of traditional chromatographic procedures. This methodology has advantages of operational simplicity, clean reaction profiles and relatively broad scope which make it more attractive for the diversity oriented synthesis of these heterocyclic libraries. In this methodology we suggest the further alternative possibility for formation of substituted pyrazoles. The compound 7h can be used as an anticancer drug in pharma industry.

Sorption and diffusion behavior of actinium(iii) ions in contact with hydroxyapatite as a transporter of medical radionuclides

2020 ◽  
Vol 69 (12) ◽  
pp. 2286-2293
Author(s):  
A. V. Severin ◽  
A. N. Vasiliev ◽  
A. V. Gopin ◽  
K. I. Enikeev
Keyword(s):  
Diffusion Behavior ◽  
And Diffusion ◽  
Medical Radionuclides

scholarly journals A Mechanism of Anti-Oxidation Coating Design Based on Inhibition Effect of Interface Layer on Ions Diffusion within Oxide Scale

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 454
Author(s):  
Bo Yu ◽  
Ya Liu ◽  
Lianqi Wei ◽  
Xiaomeng Zhang ◽  
Yingchao Du ◽  
...  
Keyword(s):  
Oxide Scale ◽  
Energy Barrier ◽  
Tetrahedral Site ◽  
Interface Layer ◽  
Diffusion Behavior ◽  
Mullite Phase ◽  
Inhibition Effect ◽  
Coating Design ◽  
Oxidation Effect ◽  
Dynamics Method

In this paper, a mechanism of anti-oxidation coating design based on the inhibition effect of the interface layer on the diffusion of ions within oxide scale was introduced. The Fe2+ ions diffusion behavior in Fe3O4, Cr2FeO4, and FeAl2O4 were studied by molecular dynamics method of Nudged elastic bond. As the result shown, Fe2+ ions tended to diffuse through the vacancy at tetrahedral site in Cr2FeO4 and FeAl2O4, but diffuse through the octahedral vacancy in Fe3O4. When temperature ranged from 1073 to 1325 K, the energy barrier of Fe2+ ions diffusion in Cr2FeO4 was higher than that of FeAl2O4, and both of that were still obvious higher than that in Fe3O4. A new anti-oxidation coating was prepared based on the inhibition of interface layer consisted of FeAl2O4 to protect the carbon steel S235JR at 1200 °C for 2 h. The FeAl2O4 region was formed and observed at the interface between coating and Fe element diffusion area, and the mullite phase was distributed outside of the FeAl2O4 region. Comparing to the bare sample, the prepared coating exhibited an excellent anti-oxidation effect.

scholarly journals Crystalline borophene quantum dots and their derivative boron nanospheres

2021 ◽  
Author(s):  
Huiqi Wang ◽  
Duo An ◽  
Mei Wang ◽  
Liwen Sun ◽  
Ying Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hydrazine Hydrate ◽  
High Power ◽  
Photoluminescence Properties ◽  
Chemical Exfoliation ◽  
One Step

Crystalline borophene quantum dots with two-photo fluorescence and their derivative boron nanospheres with hydrazine hydrate-dependent photoluminescence properties were prepared by efficient high-power sonication method combined with chemical exfoliation and one-step...

Fe/Ni diffusion behavior in the shear-extrusion solid state bonding process

2021 ◽  
Vol 67 ◽  
pp. 35-45
Author(s):  
Shuangjie Zhang ◽  
Wei Wang ◽  
Shibo Ma ◽  
Qiang Li
Keyword(s):  
Solid State ◽  
Bonding Process ◽  
Diffusion Behavior ◽  
Solid State Bonding

Zn diffusion and reflow behaviour of Sn-9Zn and Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga solders on a Ni/Cu substrate under IR reflow

2014 ◽  
Vol 26 (2) ◽  
pp. 87-95 ◽  
Author(s):  
J. Mittal ◽  
K.L. Lin
Keyword(s):  
Theoretical Calculations ◽  
Research Work ◽  
Content Type ◽  
Diffusion Behavior ◽  
Zn Diffusion ◽  
Cu Substrate ◽  
Practical Applications ◽  
Substrate Interface ◽  
Solder Balls ◽  
Practical Implications

Purpose – This paper aims to compare the reflow and Zn diffusion behaviors in Sn-Zn and Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga (5E) solders during soldering on a Ni/Cu substrate under infrared (IR) reflow. The study proposes a model on the effect of various elements particularly Zn diffusion behavior in the solders on the formation of intermetallic compounds (IMCs). Design/methodology/approach – The melting activities of two solders near their melting points on copper substrates are visualized in an IR reflow furnace. Reflowed solder joints were analyzed using scanning electron microscope and energy dispersive X-ray spectroscopy. Findings – Reflow behaviors of the solders are similar. During melting, solder balls are first merged into each other and then reflow on the substrate from top to bottom. Both solders show a reduced amount of Zn in the solder. Theoretical calculations demonstrate a higher Zn diffusion in the 5E solder; however, the amount of Zn actually observed at the solder/substrate interface is lower than Sn-9Zn solder due to the formation of ZnAg3 in the solder. A thinner IMC layer is formed at the interface in the 5E solder than the Sn-Zn solder. Research limitations/implications – The present work compares the 5E solder only with Sn-Zn solder. Additional research work may be required to compare 5E solder with other solders like Sn-Ag, SnAgCu, etc. to further establish its practical applications. Practical implications – The study ascertains the advantages of 5E solder over Sn-Zn solder for all practical applications. Originality/value – The significance of this paper is the understanding of the relation between reflow behavior of solders and reactivity of different elements in the solder alloys and substrate to form various IMCs and their influence on the formation of IMC layer at solder/substrate interface. Emphasis is provided for the diffusion behavior of Zn during reflow and respective reaction mechanisms.

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