scholarly journals Electrical conductivity of wood sawdust using graphite catalytic coating: Unlocking the microwave-assisted pyrolysis efficiency of lignocellulosic biomass

2021 ◽  
Author(s):  
Florent Bouxin ◽  
Vitaliy L. Budarin ◽  
Jiajun Fan ◽  
James Clark
Keyword(s):  
Electrical Conductivity ◽  
Lignocellulosic Biomass ◽  
Catalytic Amount ◽  
Microwave Assisted ◽  
Wood Sawdust ◽  
Catalytic Coating

The coating of the beech sawdust using a catalytic amount of graphite (as low as 0.25 wt.%) allowed a step improvement in the microwave-assisted thermolysis. Results demonstrated that the pyrolysis...

Microwave assisted synthesis of novel Pyrazole derivatives and their biological evaluation as anti-bacterial agents

2020 ◽  
Vol 23 ◽  
Author(s):  
Hadis Khodadad ◽  
Farhad Hatamjafari ◽  
Khalil Pourshamsian ◽  
Babak Sadeghi
Keyword(s):  
Antibacterial Activity ◽  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Antibacterial Activities ◽  
Structural Features ◽  
Biological Evaluation ◽  
Aureus Strain ◽  
Microwave Assisted Synthesis ◽  
Pyrazole Derivatives ◽  
Microwave Assisted

Aim and Objective: Microwave-assisted condensation of acetophenone 1 and aromatic aldehydes 2 gave chalcone analogs 3, which were cyclized to pyrazole derivatives 6a-f via the reaction with hydrazine hydrate and oxalic acid in the presence of the catalytic amount of acetic acid in ethanol. Materials and Methods: The structural features of the synthesized compounds were characterized by melting point, FT-IR, 1H, 13C NMR and elemental analysis. Results: The antibacterial activities of the synthesized pyrazoles was evaluated against three gram-positive bacteria such as Enterococcus durans, Staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria such as Escherichia coli and Salmonella typhimurium. Conclusion: All the synthesized pyrazoles showed relatively high antibacterial activity against S. aureus strain and none of them demonstrated antibacterial activity against E. coli.

Co-modification of a lignocellulosic biomass by maleic anhydride and ferric hydroxide for high-efficient biosorption of methylene blue

2021 ◽  
Author(s):  
Youcheng Gao ◽  
Jun Zeng ◽  
Siming Zhu ◽  
Qiang Liu
Keyword(s):  
Methylene Blue ◽  
Maleic Anhydride ◽  
Sugar Beet ◽  
Lignocellulosic Biomass ◽  
Ferric Hydroxide ◽  
Sugar Beet Pulp ◽  
Microwave Assisted ◽  
High Efficient ◽  
Beet Pulp ◽  
Ft Ir

Herein, a novel biosorbent originated from sugar beet pulp (SBP) was synthesized by microwave-assisted esterification with maleic anhydride (MA) and further decoration with ferric hydroxide. Characterized methods including FT-IR, SEM,...

scholarly journals Influence of Acidity and Oxidant Concentration on the Nanostructures and Electrochemical Performance of Polyaniline during Fast Microwave-Assisted Chemical Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 310 ◽  
Author(s):  
Biwei Qiu ◽  
Jingyun Wang ◽  
Zhoujing Li ◽  
Xia Wang ◽  
Xiaoyan Li
Keyword(s):  
Electrical Conductivity ◽  
Electrochemical Performance ◽  
Oxidative Polymerization ◽  
Molecular Structures ◽  
Chain Growth ◽  
Acidic Solutions ◽  
Microwave Assisted ◽  
Oxidant Concentration ◽  
Weakly Acidic Solution ◽  
Hcl Concentration

Polyaniline (PANI), a typical conducting polymer, has attracted great interest as an electrode material. A series of PANIs were prepared through fast microwave-assisted chemical oxidative polymerization with varying HCl and APS concentrations here. It was found that the microwave synthesized PANIs had ~4 times higher for the yields and 7~10 times higher for the electrical conductivity in comparison to PANI samples prepared using conventional method. PANI nanosheets could easily be fabricated in weakly acidic solution due to their oligomeric structure, which contained flat phenazine rings. By contrast, linear PANI chains produced in highly acidic solutions formed nanofibers. The APS concentration did not significantly affect the molecular structures of PANIs under the conditions here. However, increasing the concentration of APS produced nanofibers with shorter branches, which may be due to secondary nucleation during chain growth resulting from increases in active initiation centers. The electrical conductivity and electrochemical performance of PANIs were both improved with increasing HCl and APS concentrations. Improvements due to increases in HCl concentration may be attributed to additions in conjugation length and enrichment of doping levels, while improvements due to increases in APS concentration could be attributed to the increased crystallinity of PANI, which facilitates ion transport.

DC electrical conductivity retention and antibacterial aspects of microwave-assisted ultrathin CuO@polyaniline composite

2020 ◽  
Vol 74 (11) ◽  
pp. 3887-3898 ◽  
Author(s):  
Mohammad Omaish Ansari ◽  
Mohammad Oves ◽  
Numan Salah ◽  
Mohammad Asad ◽  
Rajeev Kumar ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Microwave Assisted ◽  
Dc Electrical Conductivity ◽  
Conductivity Retention

scholarly journals Microwave-Assisted Improved Regioselective Synthesis of 12H-Benzopyrano[3,2-c][1]benzopyran-5-ones by Radical Cyclisation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Pradipta Kumar Basu ◽  
Amrita Ghosh
Keyword(s):  
Microwave Irradiation ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Benzyl Bromide ◽  
Catalytic Amount ◽  
Ammonium Bromide ◽  
Catalysis Condition ◽  
Microwave Assisted ◽  
Tributyltin Hydride ◽  
Tetrabutyl Ammonium

Two new effective methodologies have been adopted for the preparation of 4-(2′-bromobenzyloxy)benzopyran-7-ones 3(a–h). In the first methodology, 4-hydroxy[1]benzopyran-2-ones 1(a–d) was alkylated with 2-bromobenzyl bromide 2a or 2-bromo-5-methoxy benzyl bromide 2b under phase transfer catalysis condition using lithium hydroxide/tetrabutyl ammonium bromide in N,N-dimethylformamide at 40–50°C and in the second method the microwave irradiation protocol has been exploited by simply mixing of 4-hydroxy[1]benzopyran-2-ones 1(a–d) with 25% excess of 2-bromobenzyl bromide 2a or 2-bromo-5-methoxy benzyl bromide 2b. A catalytic amount of TBAB and potassium carbonate were added and irradiated in an open Erlenmeyer flask in a microwave oven for 4–10 min. The tributyltin-hydride-mediated radical cyclisation of 3(a–h) was carried out under microwave irradiation to generate 12H-benzopyrano[3,2-c][1]benzopyran-5-ones 4(a–h) in 78–88% yield and in this technique yields were significantly improved and reaction time was shortened compared to the previously reported conventional radical cyclisation method.

From Lignocellulosic Biomass to Lactic- and Glycolic-Acid Oligomers: A Gram-Scale Microwave-Assisted Protocol

ChemSusChem ◽  
2015 ◽  
Vol 8 (8) ◽  
pp. 1342-1349 ◽  
Author(s):  
Diego Carnaroglio ◽  
Silvia Tabasso ◽  
Beata Kwasek ◽  
Dariusz Bogdal ◽  
Emanuela Calcio Gaudino ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Glycolic Acid ◽  
Microwave Assisted

A Convenient One-Pot and Rapid Microwave-Assisted Synthesis of Biologically Active s-Triazolo[3,4-b][1,3,4]Thiadiazine and s-Triazolo[3,4-b][1,3,4]Thiadiazole Nanoarchitectonics

2020 ◽  
Vol 20 (5) ◽  
pp. 2917-2929
Author(s):  
Ahmed F. M. EL-Mahdy ◽  
Hassan A. H. EL-Sherief ◽  
Zeinab A. Hozien ◽  
Shiao-Wei Kuo
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Reaction Time ◽  
Catalytic Amount ◽  
Biologically Active ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
Microwave Assisted ◽  
Work Up ◽  
Temperature Time

A rapid and efficient one-pot protocol has been developed for the synthesis of s-triazolo[3,4-b][1,3,4]thiadiazine and s-triazolo[3,4-b][1,3,4]thiadiazole nanoarchitectonics through the reaction of s-triazoles with ketones and nitriles in acetic acid containing a catalytic amount of sulfuric acid under microwave irradiation in excellent yields. With this catalytic reaction, the cheap sulfuric acid as well as other acids were examined as catalysts and the highly toxic and irritating haloketones and halonitriles were avoided to form. The effects of microwave power, temperature, time, solvent and catalyst were examined. This method achieved a better performance; e.g., higher yields, shorter reaction time and easier work-up as compared to other conventional methods. Therefore, the proposed method will be readily applicable to the synthesis of biologically important compounds containing s-triazolo[3,4-b][1,3,4]thiadiazine and s-triazolo[3,4-b][1,3,4]thiadiazole framework.

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